This is a system for controlling a PGA2311 or similar volume control with an Arduino. It is quite featureful, with pushbutton mute, multiple supported channels (relay switched), compile time balance, etc. Will run on most any Arduino with enough I/O for the features that desire enabling. This is a complete large system - you will have to pull out what you need for a reduced feature set.
- Rotary encoder volume control with push button mute
- Control of PGA2311 or similar volume controllers
- Channel toggle controlling input relay
- Channel and output dependent EEPROM volume save state
- Output relay for output headphone isolation / output switching
- XOR logic toggle and relay control
- Volume scaling function for smoother volume transitions
- Channel balance setting (static or adjustable)
- Limiting on maximum volume for PGA2311 control registers
- Digital I/O used: 12 pins (with adjustable balance)
- Serial debug provided if desired
- Descriptive commenting
- Code approximately 10 kB incuding serial debug
To use this code, you simply need import it to you Arduino IDE and ensure that the dependent libraries are available. You should choose which pins meet your needs and set them in the #define section. You can reverse the operation of some pins, both input switch pins and output control pins, but setting the Reverse flag, which is XOR'd with internal logic.
If you are using the PGA2311 functionality, you will want to pull up the mute pin to logical high with a suitable resistor so that it is in the mute state on turn on. You will also want to make a reasonable RC filter stage to further debounce your switches and encoder. It does not effect performance leaving the serial debug in the code even when you transition it away from the USB jumper cable. Given the use of Arduino pins 0 and 1 for the serial, you might not choose to use any of those for your pins if you are using a pre-made Arduino, such as the UNO.
You might find it prudent to trim this code to the feature set you are looking for rather than use it with all the conditional compilation. That would clean it up quite a bit and make it simpler to debug. As is clear, this code has a fair bit of flexible functionality, but it is rather a mess.
Release of this code in no way implicates that any product designed by myself or any company that I am involved with is constrained in any way to the methods and / or implications of functionality, expressly or implicitly, based on the code contained herein. The code presented here is intended as an as-is instructional collection of potential methods that may or may not be fit for any application.