ESP32-S3-LCD-1.69 more footswitching functionality

[madejm]

Hello, I'm thinking about developing more footswitch functionality for ESP32-S3-LCD-1.69.
The 12-pin header has 5 available GPIO pins: GPIO2, GPIO3, GPIO16, GPIO17 and GPIO18. Here are my ideas.

Multiple momentary footswitches

A binary switching implementation could allow for connecting multiple footswitches. With 5 GPIOs it could handle up to 31 switches. However instead of using relays or SR latches, binary signal could be done with momentary switches and diodes. Example for 3 IOs and 7 switches:

Each switch connects single/multiple diodes to the ground, resulting in a binary value on the inputs.

Effects on/off

Several footswitch signals could be mapped to turning gate, compressor, delay, modulation and reverb on and off. Quite simple idea, implementation shouldn't be too complicated, but the web configuration would have to include more detailed config of the footswitches.

Tap tempo

A new task would read the state of a single GPIO, measure time between states when the IO state is 1 and take an average. Task delay of 5ms should be enough to provide "good enough" values for two footswitch taps, and quite accurate when averaging 4 taps (for high BPM, 4 taps could differentiate between a span of 750 and 755 ms resulting in 240 and 238,4 BPM).

Please let me know if my ideas have any drawbacks or technical limitations.

[Builty]

Hi. I have just about completed the next version of firmware. The new version allows connection of up to 16 footswitches, using an I2C IO expander chip. In the web config you can select what preset switching scheme is used, and can also assign up to 5 footswitches that can be used for effect switching.

I don't have anything for tap tempo yet, but I am getting a few requests for it now.

I suggest to hold off for a little longer, so I can finish testing of V1.0.8 and I'll release that. Then you can see if that meets your needs already (apart from tap tempo which I'll need to work on.)

[madejm]

Oh I was already getting ready to start coding, but seems like I won't have to :D

Does the expander chip allow for connecting LEDs?

[madejm]

Also looking at Quad Cortex, "hold for tuner" on the Tap Tempo footswitch would be a nice feature too :D

[Builty]

The expander can drive leds, but I haven't done any code for that so far.
I'm not sure if I can launch the tuner from the USB interface, but I can investigate.