Break out more pins

[rwb27]

I’ve been thinking a bit more about this, and we might struggle for pins after all – Currently we have 14 channels of Darlington pair drivers (of which 12 are used). Extra things we might like are:

1. Limit switches (up to 3)
2. LED control (using Darlington pair or, better, i2c-controlled digital potentiometers with constant-current drivers)
3. Heater control (using one or two analogue pins plus a PWM pin for output, driving a power MOSFET)

The Nano has 14 digital pins of which 2 are the serial interface and 12 control the motors. That leaves us 8 analogue pins to play with, which would be just enough to do the 3 things above, either using a digipot + constant current circuit for the LEDs or just the darlington pairs.

[rwb27]

I think the two unused Darlington pairs are broken out now - though I don't know if that version has been uploaded (?)

[rwb27]

I'm going to make a number of more specific issues for the next revision of the board.

[rwb27]

While there are lots of nice suggestions for the next version, I think these are the most useful changes in the short term, and shouldn't be too much work...

[sctv]

As few more suggestions.... for the future.

For LEDs you could use neopixels or similar.

https://create.arduino.cc/projecthub/whimsy-makerspace/arduino-compatible-nano-neopixel-controller-6f0c4b

On the nano analogue pins 1-6 can be used as digital if required ;)

"A0-A5 can be used as: analog input/digital input/digital output.
A6 and A7 are analog inputs only." (Via https://forum.arduino.cc/index.php?topic=502105.0

[rwb27]

Thanks - that is useful. I've shied away from the neopixels for the moment, largely because my experience with other multi-colour LEDs is that the colours come from different locations on the die - while that's not an issue in lighting/display applications, it can be a real pain in microscopy.

That said, we are looking at more sophisticated condenser designs that might include diffusers, at which point neopixels might be a very good option :)

[sctv]

Its good to know about that disadvantage with multi led dies + microscopy.

…

On Wed, Dec 13, 2017 at 9:21 AM, Richard Bowman ***@***.***> wrote: Thanks - that is useful. I've shied away from the neopixels for the moment, largely because my experience with other multi-colour LEDs is that the colours come from different locations on the die - while that's not an issue in lighting/display applications, it can be a real pain in microscopy. That said, we are looking at more sophisticated condenser designs that might include diffusers, at which point neopixels might be a very good option :) — You are receiving this because you commented. Reply to this email directly, view it on GitHub <#2 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/AAAVwhDABEi3IhKMrZsCk-JQDE9pPFRxks5s_5c1gaJpZM4OH1Uu> .

-- ---------------------------------------- Brian Degger twitter: @drbrian http://makerspace.org.uk http://transitlab.org ----------------------------------------

[sangavalerian]

thanks for the comments, i am finalizing version 0.2 of sangaboard (openflexure_nano_motor_controller). This time i have used eagle.