Could use a check of my Potentiometer Board. Thank you. - Page 1
Forum section: electronics / projects

author: axeonic
author_rank: Contributor
timestamp: September 03, 2023, 08:20:29 pm
content: I am designing a PCB for a general purpose potentiometer (with 2 photoresistors) board, I've added a circuit for audio input from Arduino (PWM), with RC filtering and volume pots.It could be used with any microcontroller. I am using it with Arduino Nano for use with an audio synth library called Mozzi.Would be great if I had some fresh eyes checking for mistakes before I have sent out to be made. Would be sincerely appreciated. If anyone could use my designs, feel free to do so, e-mail me for gerber files.I've attached my 8 Pots Board and an image of the Arduino Nano board it will be connecting to.Thank you.

author: axeonic
author_rank: Contributor
timestamp: September 03, 2023, 08:22:09 pm
content: Here is the 8 Pots Board for above:

author: axeonic
author_rank: Contributor
timestamp: September 03, 2023, 08:30:34 pm
content: Sorry, posted the wrong Arduino Nano schematic with the misplaced pot caps.Here is the correct schem with pot caps fixed:

author: donlisms
author_rank: Frequent Contributor
timestamp: September 04, 2023, 12:01:13 am
content: I'm kinda curious what this board is supposed to do! :-)

author: axeonic
author_rank: Contributor
timestamp: September 04, 2023, 02:40:37 am
content: Hello,I'm using it as a general purpose pot board when using microcontrollers, or in this specific example I'll be using it to connect to the Arduino Nano for reading pots, photoresistors and for filtering PWM signals. I'll be using an audio library called Mozzi, that allows for the creation of digital audio synthesis.The pots and photoresistors control audio synthesis parameters, etc. But, this board could be used any time you need to connect a lot of pots to your microcontroller. The posted Arduino Nano board is also general purpose, but since I make audio devices I use it for digital audio.Just looking for anyone who might be able to find errors or offer advice/suggestions before I send off to get made.Thanks,TonyAme

author: ledtester
author_rank: Super Contributor
timestamp: September 04, 2023, 03:49:47 am
content: You might be interested in the design philosophy behind the Arduino "Sensor Shield".As you've probably noticed, every sensor input (both analog and digital types) often needs access to GND and Vcc so it makes sense to have a 3-pin connector for each analog and digital input. That makes it easy to mix and match the sensors attached to the microcontroller.The 3-pin headers can also be used for outputs -- e.g. LEDs, servos, speakers, ...

author: floobydust
author_rank: Super Contributor
timestamp: September 04, 2023, 04:15:28 am
content: I would consider some protection for the potentiometers. If you accidentally have an MCU pin as a digital output it will damage the potentiometer at the end. I'd add 1kΩ resistors from the wiper to the cap. You can use resistor packs as well if this is a small SMT design.Is your Nano a 3.3V or 5V one? Then the potentiometer and midi-in power etc. would need to be jumperable and go to either rail.I don't like R9 at 500kΩ it seems weird.

author: axeonic
author_rank: Contributor
timestamp: September 04, 2023, 07:05:56 am
content: Thank you. I'll consider this some more.

author: axeonic
author_rank: Contributor
timestamp: September 04, 2023, 07:08:02 am
content: Quote from: floobydust on September 04, 2023, 04:15:28 amI'll consider this too. Yeah, the 500k for R9 does seem weird... I will have to double check that, thanks for pointing that out.