Continue to Site

Welcome to our site!

Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

  • Welcome to our site! Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

Potentiometer board schematic check for boo-boos

TonyAme

New Member
Hello,

I'm designing a general purpose potentiometer board with the addition of a power input, photoresistors and a simple audio output circuit (RC filtering) and volume control. Would be great if anyone can help find any problems before I send off to get them made.

It's for use with an Arduino Nano, but can be used with any microcontroller.
1. The pots go out to the Arduino's analog input pins as does the photoresistors.
2. The audio circuit connects to a couple of digital pins on the Arduino that are sending PWM, those signals get filtered through a couple of RC filters, then out to a couple of volume control pots.

My project is for use as an digital audio synthesizer using the Mozzi audio library for Arduino, however the board is really meant for general purpose, so that I can use it with other microcontroller projects.

Sincere thanks for any help.
TonyAme
modified8PotBoard.png
 
One thought is to separate the pot supply & any pull-up resistors from the onboard 5V, and use a separate supply pin for those.

Some boards use 5V external power but 3.3V MCUs, so allowing for the 3.3V back from boards such as those would make it far more versatile.
 
One thought is to separate the pot supply & any pull-up resistors from the onboard 5V, and use a separate supply pin for those.

Some boards use 5V external power but 3.3V MCUs, so allowing for the 3.3V back from boards such as those would make it far more versatile.
A separate supply pin from the Arduino? Well, the main board that this board connects up to provides 7-9 volts straight into the Arduino, and then 5V regulated to the peripheral components (i.e, the potentiometer board). I can post the schematic to illustrate.

Thanks again,
TonyAme
 
The Arduino Due (among others), Raspberry Pi, ESP32 based modules and various others are restricted to 3.3V on the inputs, even if they use 5V for the module power supply.

I did not realise you were relying on an Arduino to provide 5V; not all devices do that and many need an external regulated 5V supply, and (for 3.3V core ones) have 3.3V out available on a separate pin.

You were specifically asking how to make it generic, to suit other microprocessor types or modules?
 
Thank you. Here is the schematic explaining the way I have the power input made.
9 volts comes in and gets routed to the Vin of the arduino, then the 9volts enters the 7805 5V power regulator and out to peripheral components such as the potentiometer board, etc.

Yes, it is general purpose for the things I make, not necessarily for other people's projects.
Thank you for looking it over, I appreciate it. (Let me know if you see anything in this new schematic; suggestions, etc.

Thanks again,
TonyAme
simplifiedNano.png
 
If you are only ever going to use it with MCUs/modules that take 7V or more in & internally run on 5V, it's fine.

However it will be unusable with the more powerful MCUs that use 5V power and 3.3V i/o - which includes many that are powerful enough for audio processing, or controlling graphics LCDs etc., like the ARM based Arduinos & other fast, large memory devices.

It's all down to what you need it to do in the future.
 
If you are only ever going to use it with MCUs/modules that take 7V or more in & internally run on 5V, it's fine.

However it will be unusable with the more powerful MCUs that use 5V power and 3.3V i/o - which includes many that are powerful enough for audio processing, or controlling graphics LCDs etc., like the ARM based Arduinos & other fast, large memory devices.

It's all down to what you need it to do in the future.
Right, thank you. I figure I can update in the future when I start using those MCU's. Thanks for bringing that to my attention.
TonyAme
 
Back
Top