"Richard Smith" wrote in message news:m1r0g5i355.fsf@void.com...

I have learned a bit of other languages.
Problem is the one-to-many relationship, as a native English speaker.
It was amazing learning some Turkish when working in Turkey.
Never took any language that far.

-----------------------------

Then I used a bad example. I'd heard that Europeans (or Continentals) tend
to learn more than one, unlike Americans. Urban Germans often knew English
while rural ones mostly didn't, and many spoke significantly different local
dialects which doubled my difficulty understanding them. It helped that some
of the differences were those by which Saxon German morphed into Old
English. For example Ein/Eine became Uh (a) and Der/Die/Das became Duh
(the).

Anyway learning computers becomes easier once you pass over the initial hump
of the seemingly unrelated basics. Programming is really just another
language, that fortunately you don't have to speak and understand in live
conversation. It's said the Romans' greatest accomplishment was being able
to speak their grammatically challenging language.

"Richard Smith" wrote in message news:m1r0g5i355.fsf@void.com...

I have learned a bit of other languages.
Problem is the one-to-many relationship, as a native English speaker.
--------------------------------

Although "dead", Latin clarified the grammar and vocabulary of many modern
European languages including English. German gave me entry to Dutch,
Scandinavian and Yiddish. French has been useful in neighboring Quebec and
some help with Spanish, in fact the two shade together across Provence and
Catalonia. I gave up on Russian when they turned inward and hostile, the
little I know is recognizable in other Slavic languages. I know the alphabet
and have some vocabulary in Greek because of its heavy use in science but
can't put a sentence together.

no@no.no (James Waldby) writes:

> Richard Smith <null@void.com> wrote:
>> "Jim Wilkins" <muratlanne@gmail.com> writes:
>>> "Richard Smith" wrote in message news:m1ttl3qahq.fsf@void.com...
>>>
>>>> "Second picture is where commented-out "pinMode(2,
>>>> INPUT_PULLUP);". Initially LED lighting randomly when button not
>>>> pressed. Then added in the circuit the "pull-up" resistor connected to
>>>> on-board supply voltage and the circuit behaved like the first
>>>> circuit."
>
> The webpage pictures and your problem descriptions aren't clear enough
> or specific enough for definitive help. Explicit wiring diagrams and
> complete code listings are needed, as well as context like Arduino
> IDE version number. <https://arduino.stackexchange.com> may be of
> help if you can fully explain what you wired up and give a
> minimum-working-example for the problem,
>
> I suggest that when getting started, you first navigate to the Blink
> sketch (run Arduino, then File / Examples / Basics / Blink) and
> compile it and download it. Then, to verify you are able to make and
> install program changes, copy it to a directory of your own with a new
> name, eg Blink2, and try a few simple changes, like substituting 13 in
> place of LED_BUILTIN, or 400 in place of 1000, etc. and download
> again. If you want to try an external LED, connect it to some other
> IO pin (not D13) with eg a 2K resistor, put that IO number into your
> Blink2, test it, etc.
>
> Then, if you are working with a program like DigitalInputPullup,
> connect a switch between an IO pin and Gnd, say D2 and ground, per
> .png-image schematics in examples/02.Digital/DigitalInputPullup .
> When you download the program to the Uno and it starts running,
> setup() will be called, which will set up serial IO and pinModes for
> D2 and D13. The pinMode(2, INPUT_PULLUP) statement places D2 into
> input mode with a pullup resistor to V+ (say 5V). That is, if D2 is
> in the INPUT_PULLUP state, an internal resistor like 35K ohms (RPU min
> 20K, max 50K per spec sheet) is connected between V+ and D2, which
> means that if you leave D2 open, D2 will sit at V+; or if you connect
> D2 to ground, after transients settle (~1us) D2 will sit at 0V, and
> some number of uA, eg 5/35000 A ~ 143 uA, will flow through the pullup
> resistor. You can measure that current by hooking an ammeter between
> the pin and ground if you want to calculate pullup resistance. If the
> current's really high or is zero the pin's not in INPUT_PULLUP mode.
> If you have an external pullup and turn on INPUT_PULLUP, the effective
> pullup resistance is the two resistors in parallel. If your external
> resistor is a pulldown (connected to Gnd instead of V+) the open-pin
> voltage [open aside from pull resistors] will be that of a resistor
> divider, instead of 0 or V+.
>
> Re the I2C problem with your MCP9600 breakout board - Again, wiring
> diagrams and code listings are needed for diagnosis. One comment: You
> could write an if statement to try both addresses, 0x66 and 0x67,
> mentioned in the Pimoroni page, or a loop to try the whole range
> 0x60-0x67, proceeding ahead when a ready-test succeeds. Or, for
> simpler programming you could make a program with one address,
> download and test it, then change it for each possible address until
> successful. The I2C fails I've seen were due to wrong addresses,
> miswiring, bad chips, or in one case wires longer than a few feet.
>
>>> Unconnected inputs are sensitive antennas that pick up secret messages
>>> from space, or noise from fluorescent lights and radio/TV
>>> transmitters. Some even float to a middle level where they partly turn
>>> on both the input high and input low circuits, causing oscillation or
>>> higher power consumption. They are all best made high or low if not
>>> used. [...]
>
> Setting an open IO to low or high output like that is one approach,
> but on the Arduino Uno a simpler / less risky approach is to set
> pinMode to INPUT_PULLUP. Note, ATmega328P microcontroller chip
> hardware as on an Uno sets all IO pins to INPUT during Reset, but boot
> firmware changes the modes of some pins like D0, D1, D13 as per eg
> <https://forum.arduino.cc/t/behavior-of-pins-during-reset-state/640285/12>
>
>> It is a bit of a thought that I would need an oscilloscope to
>> proceed much further.
>
> One can do a lot with indicator LEDs attached to several outputs. You
> can connect a resistor in series with an LED between an IO pin and
> ground or 5V. Eg, a 3.5V LED with a 1.5K resistor will draw 1 mA,
> either when the pin is low if series is between 5V and pin, or when
> the pin is high if series is between Gnd and pin. ( 0.001 A =
> (5V-3.5V)/1500 ohms.) Or, because modern LEDs light up ok (visible
> but not annoyingly bright) with a few microamps, you can connect an
> LED between an IO pin and Gnd; turn it on with perhaps 43 uA, ie
> (5V-3.5V)/35000 ohms, when you set pinMode to INPUT_PULLUP; turn it
> off by setting pinMode to INPUT. Note, outputting debug data via the
> serial port also is easy to do with Arduino.
>
> If you are uncertain how much electronics work you'll do, or have to
> really economize, an item like <https://www.amazon.com/dp/B0C6XPVLPZ>
> ($37) would get you at least basic scope function, making it possible
> to see switch bounce, PWM sequences, and other low frequency stuff.
> For a hundred or two more, you can get a 50MHz 2 channel scope like
> previously mentioned, a big step up. If you're into micros for the
> long term, go ahead and get a medium cost 4 channel 100MHz or 200MHz
> scope, somewhere between $300 and $800. Scopes in that range often
> have an input to accept data from optional add-on logic analyzer
> modules, adding 8 or more 0-1 inputs, and often have builtin protocol
> analyzers. Eg, besides displaying an I2C waveform they show its data
> content as text on the screen.
>
>> I have seen videos of them used to diagnose even what is happening
>> when you push a push-button - all sorts of noise! With the
>> oscilloscope showing very clearly.
>
> It's mostly switch bounce, not noise. On some switches bounce will be
> over within just a few milliseconds (ms), on others it can be dozens
> of ms. With search terms = arduino debounce, you can find code
> examples plus simple switch or switch+resistor circuits, and may also
> see pages like below with more-complex Schmitt trigger hardware
> debounce, or with low-pass filters, which in some cases are truely
> awful, amazingly bad. Following link explains bounce problem and
> shows hardware and software debouncing with detailed code notes.
> <https://www.circuitbasics.com/how-to-use-switch-debouncing-on-the-arduino/>

Hi James, everyone

Thanks for the ideas in your reply.

Do thing of copying the example code then adding features.
eg. "blink" -> flashes-out morse code with LED on "breadboard"
At least got that far.

Addresses hint re. Arduino I2C to breakout board great.

Maybe accept crawl before tray to walk - do simpler code just to see if
can get the I2C connection going - forget trying to read the
thermocouple yet?
Thinking of the idea of trying the addresses.

Rich S

On Tue, 19 Mar 2024 10:05:11 -0400, Leon Fisk <lfiskgr@gmail.invalid>
wrote:

>On Tue, 19 Mar 2024 09:12:40 -0400
>"Jim Wilkins" <muratlanne@gmail.com> wrote:
>
><snip>
>>As an example the specs on this look adequate for troubleshooting I2C
>>waveforms.
>>https://www.amazon.com/FNIRSI-1013D-Oscilloscope-Handheld-Bandwidth/dp/B0BB2GTM1J
>
>I find the test equipment available nowadays truly amazing and
>especially at that price... However my old stuff from ~30 years ago
>still works (some pots and switches could use cleaning) and I wonder
>how long these new items will last. Of course if they were to work for
>another 20 years I'll not likely be around to complain about it?
I picked up a cheap portable storage scome (single chanel only) for
that kind of work then stumpled across a primo Tektronics 465 with
the DM44 add-on for $50. I had been scopeless for a couple decades
since my old Heathkit blew a couple capacitors (with a big bang and
lots of smoke)
Picker it up to do some automotive electronic troubleshooting - and
made a pressure pulse sensor for it as well.

On Tue, 19 Mar 2024 11:31:57 -0400, Leon Fisk <lfiskgr@gmail.invalid>
wrote:

>On Tue, 19 Mar 2024 10:44:31 -0400
>"Jim Wilkins" <muratlanne@gmail.com> wrote:
>
><snip>
>>A 5-1/2 digit Fluke 8800A bench multimeter from around 1980 that I bought
>>for $25 still matches a calibrated voltage standard to the last count.
>>Industry dumps equipment (and people) when age makes their reliability
>>questionable.
>
>I picked up (Ebay) a Fluke 8010A and a 37 a few years ago. Was
>hoping for the best but they both need work. Would really like to get
>the 37 working. It's a lot like my 87 but not quite the same spec. Has
>a bargraph display which can be handy when tuning circuits. Made to
>sit on a bench or portable. Uses a 9v battery, same as 87 series.
>Suspect the input protection, "Varistors" maybe flakey. I ordered some
>in but have been too lazy to seriously dig into it? The 8010A may need
>some serious switch work/cleaning. Used to see those switches in radio
>equipment and they were prone for dirt/noise. Royal pain to desolder
>and probably unobtanium to replace nowadays. So need to be carefully
>disassembled and cleaned...
>
>I don't lack for projects just the drive to do it?

I've found Stabilant22 can make a HUGE difference in electronic
connections that are "noisy" or intermitternt. Pricy stuff at about
$400 an ounce but it goes a long way. 1/4 ounce mixed with 3/4 oz of
99.9 ethanol makes an ounce of 22E for about $100 - the last ounce
lasted me about 20 years. Just mixed 2 oz of 22E and 2 oz of 22A
(mixed with 99% IPA) yesterday. $5 an ounce for the ethanol and $7 for
half a liter of IPA - (and no, not the hoppy beverage libation 111)

One drop of the stuff can make a noisy control DEAD QUIET. or an
intermittent connection rock solid Used on test lead plugs? fantastic
- electrically virtually identical to a good soldered joint and no
worries about shorts between pins etc. I stumbled across the stuff
when working on American Megatrends mother boards back when all the
memory and most other chips were still socketted and the pin
connections would get flaky from heat cycling. You could re-seat the
chips once every 2 months - or use a bit of Stabilant22 and never
touch them again for 5 years. with 3 year warrany on our machines the
stuff was worth it's weight in platinum in eliminating over 90% of
warranty claims

On Wed, 20 Mar 2024 16:54:36 -0400
Clare Snyder <clare@snyder.on.ca> wrote:

<snip>
>I picked up a cheap portable storage scome (single chanel only) for
>that kind of work then stumpled across a primo Tektronics 465 with
>the DM44 add-on for $50...

Yowza! That's a really nice looking scope👍 I can't beat that deal...

--
Leon Fisk
Grand Rapids MI

On Tue, 19 Mar 2024 18:02:56 -0400, Leon Fisk <lfiskgr@gmail.invalid>
wrote:

>On Tue, 19 Mar 2024 17:34:20 -0400
>"Jim Wilkins" <muratlanne@gmail.com> wrote:
>
><snip>
>>Thanks. I was taught to use an ink eraser to clean contacts. The Army tool
>>kits for telephone and Teletype repairmen included contact burnishers. The
>>school concentrated on electronics, ciphony and Modems, and slighted the
>>mechanical components.
>>https://jonard.com/contact-burnishers-burnisher-files
>
>I was using "burnish" in a general sense. It's really hard to get
>anything inside those switch shells to clean up the contact area. So
>maybe a Q-tip with something on it, bit of cloth held in a hemostat...
>you have to improvise with something depending on how bad they look to
>be?
>
>I have several different erasers, they work pretty good if they can
>reach the problem area?
There used to be a "tuner lube" for mechanical TV tuners that had a
real fine abrassive in it - the stuff was a black paste in a
hypordermic needle that you very carefully squirted in to the contacts
of all the wafer switches inTV tuners to "quiet" them down. My lat
tube hardened up and gat thrownout tears ago - I think it was from M-G
Chemicals (same company that manufactures Stabilant up here north of
Toronto) - Their NuTrol is a pretty decent volume control cleaner too.

On Wed, 20 Mar 2024 07:47:03 -0000 (UTC), no@no.no (James Waldby)
wrote:

>Richard Smith <null@void.com> wrote:
>> "Jim Wilkins" <muratlanne@gmail.com> writes:
>>> "Richard Smith" wrote in message news:m1ttl3qahq.fsf@void.com...
>>>
>>>> "Second picture is where commented-out "pinMode(2,
>>>> INPUT_PULLUP);". Initially LED lighting randomly when button not
>>>> pressed. Then added in the circuit the "pull-up" resistor connected to
>>>> on-board supply voltage and the circuit behaved like the first
>>>> circuit."
>
>The webpage pictures and your problem descriptions aren't clear enough
>or specific enough for definitive help. Explicit wiring diagrams and
>complete code listings are needed, as well as context like Arduino
>IDE version number. <https://arduino.stackexchange.com> may be of
>help if you can fully explain what you wired up and give a
>minimum-working-example for the problem,
>
>I suggest that when getting started, you first navigate to the Blink
>sketch (run Arduino, then File / Examples / Basics / Blink) and
>compile it and download it. Then, to verify you are able to make and
>install program changes, copy it to a directory of your own with a new
>name, eg Blink2, and try a few simple changes, like substituting 13 in
>place of LED_BUILTIN, or 400 in place of 1000, etc. and download
>again. If you want to try an external LED, connect it to some other
>IO pin (not D13) with eg a 2K resistor, put that IO number into your
>Blink2, test it, etc.
>
>Then, if you are working with a program like DigitalInputPullup,
>connect a switch between an IO pin and Gnd, say D2 and ground, per
>.png-image schematics in examples/02.Digital/DigitalInputPullup .
>When you download the program to the Uno and it starts running,
>setup() will be called, which will set up serial IO and pinModes for
>D2 and D13. The pinMode(2, INPUT_PULLUP) statement places D2 into
>input mode with a pullup resistor to V+ (say 5V). That is, if D2 is
>in the INPUT_PULLUP state, an internal resistor like 35K ohms (RPU min
>20K, max 50K per spec sheet) is connected between V+ and D2, which
>means that if you leave D2 open, D2 will sit at V+; or if you connect
>D2 to ground, after transients settle (~1us) D2 will sit at 0V, and
>some number of uA, eg 5/35000 A ~ 143 uA, will flow through the pullup
>resistor. You can measure that current by hooking an ammeter between
>the pin and ground if you want to calculate pullup resistance. If the
>current's really high or is zero the pin's not in INPUT_PULLUP mode.
>If you have an external pullup and turn on INPUT_PULLUP, the effective
>pullup resistance is the two resistors in parallel. If your external
>resistor is a pulldown (connected to Gnd instead of V+) the open-pin
>voltage [open aside from pull resistors] will be that of a resistor
>divider, instead of 0 or V+.
>
>Re the I2C problem with your MCP9600 breakout board - Again, wiring
>diagrams and code listings are needed for diagnosis. One comment: You
>could write an if statement to try both addresses, 0x66 and 0x67,
>mentioned in the Pimoroni page, or a loop to try the whole range
>0x60-0x67, proceeding ahead when a ready-test succeeds. Or, for
>simpler programming you could make a program with one address,
>download and test it, then change it for each possible address until
>successful. The I2C fails I've seen were due to wrong addresses,
>miswiring, bad chips, or in one case wires longer than a few feet.
>
>>> Unconnected inputs are sensitive antennas that pick up secret messages
>>> from space, or noise from fluorescent lights and radio/TV
>>> transmitters. Some even float to a middle level where they partly turn
>>> on both the input high and input low circuits, causing oscillation or
>>> higher power consumption. They are all best made high or low if not
>>> used. [...]
>
>Setting an open IO to low or high output like that is one approach,
>but on the Arduino Uno a simpler / less risky approach is to set
>pinMode to INPUT_PULLUP. Note, ATmega328P microcontroller chip
>hardware as on an Uno sets all IO pins to INPUT during Reset, but boot
>firmware changes the modes of some pins like D0, D1, D13 as per eg
><https://forum.arduino.cc/t/behavior-of-pins-during-reset-state/640285/12>
>
>> It is a bit of a thought that I would need an oscilloscope to
>> proceed much further.
>
>One can do a lot with indicator LEDs attached to several outputs. You
>can connect a resistor in series with an LED between an IO pin and
>ground or 5V. Eg, a 3.5V LED with a 1.5K resistor will draw 1 mA,
>either when the pin is low if series is between 5V and pin, or when
>the pin is high if series is between Gnd and pin. ( 0.001 A =
>(5V-3.5V)/1500 ohms.) Or, because modern LEDs light up ok (visible
>but not annoyingly bright) with a few microamps, you can connect an
>LED between an IO pin and Gnd; turn it on with perhaps 43 uA, ie
>(5V-3.5V)/35000 ohms, when you set pinMode to INPUT_PULLUP; turn it
>off by setting pinMode to INPUT. Note, outputting debug data via the
>serial port also is easy to do with Arduino.
>
>If you are uncertain how much electronics work you'll do, or have to
>really economize, an item like <https://www.amazon.com/dp/B0C6XPVLPZ>
>($37) would get you at least basic scope function, making it possible
>to see switch bounce, PWM sequences, and other low frequency stuff.
>For a hundred or two more, you can get a 50MHz 2 channel scope like
>previously mentioned, a big step up. If you're into micros for the
>long term, go ahead and get a medium cost 4 channel 100MHz or 200MHz
>scope, somewhere between $300 and $800. Scopes in that range often
>have an input to accept data from optional add-on logic analyzer
>modules, adding 8 or more 0-1 inputs, and often have builtin protocol
>analyzers. Eg, besides displaying an I2C waveform they show its data
>content as text on the screen.
>
>> I have seen videos of them used to diagnose even what is happening
>> when you push a push-button - all sorts of noise! With the
>> oscilloscope showing very clearly.
>
>It's mostly switch bounce, not noise. On some switches bounce will be
>over within just a few milliseconds (ms), on others it can be dozens
>of ms. With search terms = arduino debounce, you can find code
>examples plus simple switch or switch+resistor circuits, and may also
>see pages like below with more-complex Schmitt trigger hardware
>debounce, or with low-pass filters, which in some cases are truely
>awful, amazingly bad. Following link explains bounce problem and
>shows hardware and software debouncing with detailed code notes.
><https://www.circuitbasics.com/how-to-use-switch-debouncing-on-the-arduino/>
The arduino instructions say to tie all unused digital inputs either
high or low and all analog inputs low to prevent ambiguous outputs.
and don't forget de-spiking capacitors still work on
Microprocessors!!!

On Wed, 20 Mar 2024 10:55:18 +0000, Richard Smith <null@void.com>
wrote:

>I have learned a bit of other languages.
>Problem is the one-to-many relationship, as a native English speaker.
>It was amazing learning some Turkish when working in Turkey.
>Never took any language that far.
Took a bit of French in grade 9 - that's 60 years ago - and a
conversational Spanish course back in about '76. The 2 languages are
just close enough I managed to get out SOME "Spenchlish" for a couple
of years - - -
My eldest daughter (turnd 42 on Sunday) has worked predominantly in
French for about 12 years (in charge of programs in a large part of
French West Africa for a major NGO)
She's made good use of her French Immersion schooling.

On Wed, 20 Mar 2024 16:30:43 +0000, Richard Smith <null@void.com>
wrote:

>no@no.no (James Waldby) writes:
>
>> Richard Smith <null@void.com> wrote:
>>> "Jim Wilkins" <muratlanne@gmail.com> writes:
>>>> "Richard Smith" wrote in message news:m1ttl3qahq.fsf@void.com...
>>>>
>>>>> "Second picture is where commented-out "pinMode(2,
>>>>> INPUT_PULLUP);". Initially LED lighting randomly when button not
>>>>> pressed. Then added in the circuit the "pull-up" resistor connected to
>>>>> on-board supply voltage and the circuit behaved like the first
>>>>> circuit."
>>
>> The webpage pictures and your problem descriptions aren't clear enough
>> or specific enough for definitive help. Explicit wiring diagrams and
>> complete code listings are needed, as well as context like Arduino
>> IDE version number. <https://arduino.stackexchange.com> may be of
>> help if you can fully explain what you wired up and give a
>> minimum-working-example for the problem,
>>
>> I suggest that when getting started, you first navigate to the Blink
>> sketch (run Arduino, then File / Examples / Basics / Blink) and
>> compile it and download it. Then, to verify you are able to make and
>> install program changes, copy it to a directory of your own with a new
>> name, eg Blink2, and try a few simple changes, like substituting 13 in
>> place of LED_BUILTIN, or 400 in place of 1000, etc. and download
>> again. If you want to try an external LED, connect it to some other
>> IO pin (not D13) with eg a 2K resistor, put that IO number into your
>> Blink2, test it, etc.
>>
>> Then, if you are working with a program like DigitalInputPullup,
>> connect a switch between an IO pin and Gnd, say D2 and ground, per
>> .png-image schematics in examples/02.Digital/DigitalInputPullup .
>> When you download the program to the Uno and it starts running,
>> setup() will be called, which will set up serial IO and pinModes for
>> D2 and D13. The pinMode(2, INPUT_PULLUP) statement places D2 into
>> input mode with a pullup resistor to V+ (say 5V). That is, if D2 is
>> in the INPUT_PULLUP state, an internal resistor like 35K ohms (RPU min
>> 20K, max 50K per spec sheet) is connected between V+ and D2, which
>> means that if you leave D2 open, D2 will sit at V+; or if you connect
>> D2 to ground, after transients settle (~1us) D2 will sit at 0V, and
>> some number of uA, eg 5/35000 A ~ 143 uA, will flow through the pullup
>> resistor. You can measure that current by hooking an ammeter between
>> the pin and ground if you want to calculate pullup resistance. If the
>> current's really high or is zero the pin's not in INPUT_PULLUP mode.
>> If you have an external pullup and turn on INPUT_PULLUP, the effective
>> pullup resistance is the two resistors in parallel. If your external
>> resistor is a pulldown (connected to Gnd instead of V+) the open-pin
>> voltage [open aside from pull resistors] will be that of a resistor
>> divider, instead of 0 or V+.
>>
>> Re the I2C problem with your MCP9600 breakout board - Again, wiring
>> diagrams and code listings are needed for diagnosis. One comment: You
>> could write an if statement to try both addresses, 0x66 and 0x67,
>> mentioned in the Pimoroni page, or a loop to try the whole range
>> 0x60-0x67, proceeding ahead when a ready-test succeeds. Or, for
>> simpler programming you could make a program with one address,
>> download and test it, then change it for each possible address until
>> successful. The I2C fails I've seen were due to wrong addresses,
>> miswiring, bad chips, or in one case wires longer than a few feet.
>>
>>>> Unconnected inputs are sensitive antennas that pick up secret messages
>>>> from space, or noise from fluorescent lights and radio/TV
>>>> transmitters. Some even float to a middle level where they partly turn
>>>> on both the input high and input low circuits, causing oscillation or
>>>> higher power consumption. They are all best made high or low if not
>>>> used. [...]
>>
>> Setting an open IO to low or high output like that is one approach,
>> but on the Arduino Uno a simpler / less risky approach is to set
>> pinMode to INPUT_PULLUP. Note, ATmega328P microcontroller chip
>> hardware as on an Uno sets all IO pins to INPUT during Reset, but boot
>> firmware changes the modes of some pins like D0, D1, D13 as per eg
>> <https://forum.arduino.cc/t/behavior-of-pins-during-reset-state/640285/12>
>>
>>> It is a bit of a thought that I would need an oscilloscope to
>>> proceed much further.
>>
>> One can do a lot with indicator LEDs attached to several outputs. You
>> can connect a resistor in series with an LED between an IO pin and
>> ground or 5V. Eg, a 3.5V LED with a 1.5K resistor will draw 1 mA,
>> either when the pin is low if series is between 5V and pin, or when
>> the pin is high if series is between Gnd and pin. ( 0.001 A =
>> (5V-3.5V)/1500 ohms.) Or, because modern LEDs light up ok (visible
>> but not annoyingly bright) with a few microamps, you can connect an
>> LED between an IO pin and Gnd; turn it on with perhaps 43 uA, ie
>> (5V-3.5V)/35000 ohms, when you set pinMode to INPUT_PULLUP; turn it
>> off by setting pinMode to INPUT. Note, outputting debug data via the
>> serial port also is easy to do with Arduino.
>>
>> If you are uncertain how much electronics work you'll do, or have to
>> really economize, an item like <https://www.amazon.com/dp/B0C6XPVLPZ>
>> ($37) would get you at least basic scope function, making it possible
>> to see switch bounce, PWM sequences, and other low frequency stuff.
>> For a hundred or two more, you can get a 50MHz 2 channel scope like
>> previously mentioned, a big step up. If you're into micros for the
>> long term, go ahead and get a medium cost 4 channel 100MHz or 200MHz
>> scope, somewhere between $300 and $800. Scopes in that range often
>> have an input to accept data from optional add-on logic analyzer
>> modules, adding 8 or more 0-1 inputs, and often have builtin protocol
>> analyzers. Eg, besides displaying an I2C waveform they show its data
>> content as text on the screen.
>>
>>> I have seen videos of them used to diagnose even what is happening
>>> when you push a push-button - all sorts of noise! With the
>>> oscilloscope showing very clearly.
>>
>> It's mostly switch bounce, not noise. On some switches bounce will be
>> over within just a few milliseconds (ms), on others it can be dozens
>> of ms. With search terms = arduino debounce, you can find code
>> examples plus simple switch or switch+resistor circuits, and may also
>> see pages like below with more-complex Schmitt trigger hardware
>> debounce, or with low-pass filters, which in some cases are truely
>> awful, amazingly bad. Following link explains bounce problem and
>> shows hardware and software debouncing with detailed code notes.
>> <https://www.circuitbasics.com/how-to-use-switch-debouncing-on-the-arduino/>
>
>Hi James, everyone
>
>Thanks for the ideas in your reply.
>
>Do thing of copying the example code then adding features.
>eg. "blink" -> flashes-out morse code with LED on "breadboard"
>At least got that far.
>
>Addresses hint re. Arduino I2C to breakout board great.
>
>Maybe accept crawl before tray to walk - do simpler code just to see if
>can get the I2C connection going - forget trying to read the
>thermocouple yet?
>Thinking of the idea of trying the addresses.
>
>Rich S
The most I ever accomplished was a remote elevator trim for homebuilt
(experimental) aircraft using a large scale Radio control servo driven
by the arwuino with 2 push buttons for "UP" and "DOWN" and one for
"reset to neutral" - with a small micro-servo slaved as the trim
indicator on the panel. Then I had fuel guages using pressure
transfucers plumbed into the bottom of the tank that calculated the
volume by the fuel column weight and converted togallons in the tank
using a table ofvolume per inch of depth (irregular tank shape)

I just started out with some sample "sketches" and built from there.
After getting a sketch working to do one part of the job, I'd set it
asife and work on another function - then link the sketches together -
calling them as sub-routines as required.

each project took several weeks of spare time

There was enough capacity for one Arduino to handle both tasks, but I
wasn't smart enough to combine the 2 programs and I felt safer with
the 2 functions on separate controllers in case of a failure - where I
would only lose one function at a time - - -
Sold the plane before I got a chance to fly it.

"Richard Smith" wrote in message news:m1h6h0987g.fsf@void.com...

Hi James, everyone

Thanks for the ideas in your reply.

Do thing of copying the example code then adding features.
eg. "blink" -> flashes-out morse code with LED on "breadboard"
At least got that far.

Addresses hint re. Arduino I2C to breakout board great.

Maybe accept crawl before tray to walk - do simpler code just to see if
can get the I2C connection going - forget trying to read the
thermocouple yet?
Thinking of the idea of trying the addresses.

Rich S

-------------------------------------------
For me finding and correcting programming errors is hard enough that I try
one new thing at a time so I know at least where to look if it fails. That's
why I decide and test how to display dummy data before measuring it for
real. I2C data may be useful if shown both as binary bits and their
numerical equivalent, for configuration and temperature.

I've programmed since the early 80's but a few days ago I got tangled in a
simple IF THEN ELSE in a spreadsheet. After breaking off to do something
else and returning with fresh eyes the typing error was obvious.

On Wed, 20 Mar 2024 17:16:52 -0400, Leon Fisk <lfiskgr@gmail.invalid>
wrote:

>On Wed, 20 Mar 2024 16:54:36 -0400
>Clare Snyder <clare@snyder.on.ca> wrote:
>
><snip>
>>I picked up a cheap portable storage scome (single chanel only) for
>>that kind of work then stumpled across a primo Tektronics 465 with
>>the DM44 add-on for $50...
>
>Yowza! That's a really nice looking scope? I can't beat that deal...

It was something of an estate sale. The old guy had been an engineer
with Square D Canada and Allen Bradley (Rockwell Automation) and
continued doing some repair work at home after retirement and had
ammassed a PILE of "stuff" the family had to dispose of after his
death. I cot boxed of compinents, 8X10X2 inches for $2 Canafian each -
the scope, a decade resistir sub box, a 10 amp CanLab Powerstat in a
nice cabinet, Also a brand new foot swith unit with a heavcy magnetic
contactor - all in nice cabinetry and a brand new Sencore SCR tester
(but without the required Sencore Megger to use it woith - know anyone
who needs it?) I think the total was $75 or $80. There was still a
truck-load in the garage when I left - but I had no room for any more
- wife's always at me to get rid of "stuff"

Jim Wilkins <muratlanne@gmail.com> wrote:
> "James Waldby" wrote in message news:ute49n$1ci6f$1@dont-email.me...
[big snip]
> --------------------------
> Thanks, I'm glad someone whose Arduino experience is less archaic than mine
> has jumped in. I think in hardware terms, voltage and current, and should
> have clarified that INPUT_PULLUP is sufficient to make the pin high.
>
> The $23 one-channel DSO211 oscilloscope I have doesn't seem available and
> wouldn't capture both I2C signals so I didn't suggest it. I bought it for
> signals whose return can't be grounded.

Yes, it's a good feature of battery-powered small cheap scopes that
they allow ungrounded operation. As you note, some of them can't
capture I2C, which I didn't think about WRT the cheap scope I linked.
It does 250 KHz, not good enough for `Fast Mode` I2C at 400 KHz, let
alone the 3.4 MHz and 5 MHz versions of I2C.
> IIRC the Arduino needed a separate terminal to talk to the user, the IDE
> didn't provide that function. Does it now?

I think a decade ago there were some issues with Serial.printf, and
some serial-over-USB drivers had bugs that hung around a while, but
for a good while the same USB link used to program an Arduino Uno or
Nano has been working fine for serial IO to a window that's part of
the IDE. However, on Linux at least, a not-IDE Python or C program
can't share a serial link with the IDE; one or the other has to
relinquish it.

Note, the IDE now has an easy-to-use Serial Plotter tool. If a sketch
outputs some numbers on each line of serial output and you open a
Serial Plotter window, data will be plotted as it arrives, like on a
multi-channel scope.

> The simplest switch debouncer I've seen and used is a spare buffer
> or noninverting gate(s) with a feedback resistor from output to
> input that makes it retain its logic level until the switch on its
> input yanks it to the other one. The switch needs to be double
> throw, connected to both power and ground, the resistor limits gate
> output current. In the days of hardwired logic there were almost
> always spare gates available.

At the time, gates were cheaper than lines of code, vs the other way
around now. But if an application has lots of switches, software
debounce may be to much of a challenge for some programmers. So there
are libraries, eg Bounce2, that can be used to take care of software
debounce with a not-too-bad learning curve.

Clare Snyder <clare@snyder.on.ca> wrote:
> On Wed, 20 Mar 2024 07:47:03 -0000 (UTC), (James Waldby) wrote:
>>Richard Smith <null@void.com> wrote:
>>> "Jim Wilkins" <muratlanne@gmail.com> writes:
>>>> "Richard Smith" wrote in message news:m1ttl3qahq.fsf@void.com...
>>>>> "Second picture is where commented-out "pinMode(2,
>>>>> INPUT_PULLUP);". Initially LED lighting randomly when button not
>>>>> pressed. Then added in the circuit the "pull-up" resistor connected to
>>>>> on-board supply voltage and the circuit behaved like the first
>>>>> circuit."
[snip]
>>>> Unconnected inputs are sensitive antennas that pick up secret messages
>>>> from space, or noise from fluorescent lights and radio/TV
>>>> transmitters. Some even float to a middle level where they partly turn
>>>> on both the input high and input low circuits, causing oscillation or
>>>> higher power consumption. They are all best made high or low if not
>>>> used. [...]

>>Setting an open IO to low or high output like that is one approach,
>>but on the Arduino Uno a simpler / less risky approach is to set
>>pinMode to INPUT_PULLUP. Note, ATmega328P microcontroller chip
>>hardware as on an Uno sets all IO pins to INPUT during Reset, but boot
>>firmware changes the modes of some pins like D0, D1, D13 as per eg
>><https://forum.arduino.cc/t/behavior-of-pins-during-reset-state/640285/12>
[snip]

> The arduino instructions say to tie all unused digital inputs either
> high or low and all analog inputs low to prevent ambiguous outputs.

That's probably ok advice in general, particularly for an Arduino Uno
being used for numerous projects. But setting the modes of unused
inputs to INPUT_PULLUP seems safer, because then they won't be at risk
of Gnd-to-V+ shorts due to program glitches. That aside, I should do
some measurements to see which is best among the various INPUT /
OUTPUT / INPUT_PULLUP modes, with input left open / connected to Gnd /
connected to V+. Note, some Arduino inputs don't have internal
pullups available. For example, A6 and A7 on Arduinos with ATmega -P
and -PA processors, and most IO pins on ESP8266-based micros.

To Richard: The IDE is the computer host program that communicates with the
Arduino. Input pullups are generally harmless except on analog inputs making
measurements.

I haven't seen a floating input cause an overheating problem on a device
released for production but I have in R&D where I found the resulting hot
spot on the chip with a microscope and infrared camera.
https://www.waferworld.com/post/what-is-a-wafer-prober

Inputs and outputs have normally reverse-biased clamp diodes to (+) and Gnd,
either inherently or for static protection. An external High signal on a pin
when the device isn't powered up will pass through them to the device power
supply and try to power the board and charge its bypass capacitors, which
may damage the pin or the signal source. This means one switch should
control the power for every board in the circuit.

Some power supplies don't take well to externally applied voltage on their
output when they are turned off, or higher than their set point. This is
mainly a concern when using them to charge batteries, also some
consideration in bench test setups.

Hot-pluggables like USB have (or should) built-in surge current limiters to
prevent damage or voltage dips in the source. They may be a series
"thermistor" whose resistance increases sharply when they warm up. Otherwise
plugging in a USB device could crash the computer. For USB2 the current
limit is 0.5A, with some brief overload capacity to charge capacitors. If a
USB-powered board and whatever you add to it draws more current the USB 5V
output may drop and the board not work right.

"James Waldby" wrote in message news:utgg8s$21ao1$1@dont-email.me...

Yes, it's a good feature of battery-powered small cheap scopes that
they allow ungrounded operation. As you note, some of them can't
capture I2C, which I didn't think about WRT the cheap scope I linked.
It does 250 KHz, not good enough for `Fast Mode` I2C at 400 KHz, let
alone the 3.4 MHz and 5 MHz versions of I2C.

---------------------------
He could setClock() low enough for it. That scope would be fast enough for
most of my hobby use, though I was spoiled by the $20,000 scope I ordered
for digital radio data speeds. The company had one that went to 70GHz, with
liquid helium cooled Josephson junction input amplifiers. They used it to
develop military satellite uplinks, then parked it and its Dewar in the back
of my lab. Since it lacked storage and even a trigger it wasn't generally
useful. Mostly I used an HP8753 vector network analyzer instead of a scope
above 1GHz.

Digital radio tech has made them very affordable:
https://nanovna.com/?page_id=21

Unlike many other communications protocols I2C doesn't depend on timing
accuracy and the actual speed can be whatever suits the controller hardware
and software, without bothering with timing. It is event-driven, the rising
SCL clock edge indicates when to put SDA data on the bus, the falling edge
of SCL when to read it, a microSecond or a day later. A program may impose
an arbitrary timeout to detect a bad connection. In practice the upper speed
limit depends on how quickly the pullup resistors can charge the capacitance
of the interconnecting wires, which is why their length is limited.
https://docs.arduino.cc/learn/communication/wire/

"James Waldby" wrote in message news:utgg8s$21ao1$1@dont-email.me...

Yes, it's a good feature of battery-powered small cheap scopes that
they allow ungrounded operation. As you note, some of them can't
capture I2C, which I didn't think about WRT the cheap scope I linked.
It does 250 KHz, not good enough for `Fast Mode` I2C at 400 KHz, let
alone the 3.4 MHz and 5 MHz versions of I2C.

------------------------------------
Amazon shows other low cost scopes with 2 channels and higher bandwidth.
Their operation is entirely by menu choices which is initially confusing for
me, a user since the big vacuum tube Tektronix era, let alone a newbie to
scope use with only a vaguely worded instruction sheet and no other owners
to ask for help.

I use Amazon as an aggregator of similar items, for an overview of what's
available with user reviews, not necessarily as the seller I buy from.

"Jim Wilkins" <muratlanne@gmail.com> writes:

> To Richard: The IDE is the computer host program that communicates
> with the Arduino. Input pullups are generally harmless except on
> analog inputs making measurements.
>
> ...

Lot to learn...
Mercifully with the current price of devices, can get on with
applications and learn by trial-and-error.

On Thu, 21 Mar 2024 17:55:39 -0400
"Jim Wilkins" <muratlanne@gmail.com> wrote:

<snip>
>I use Amazon as an aggregator of similar items, for an overview of what's
>available with user reviews, not necessarily as the seller I buy from.

I do this with almost everything new[1] I buy nowadays. Helps to
determine a fair price and most importantly if a product has some
serious defects and best to avoid...

[1] A product new to me, that I haven't bought before or investigated.

--
Leon Fisk
Grand Rapids MI