When I was first testing this, I made a break-out board for an Arduino Mega. I designed a 32key Matrix key panel with LEDs at the same time. When I got that working with Arduino connector, I was not happy with the pulsing effect of the LEDs. I also had pretty bad lag (which seems it may have been resolved with adjusting the serial timeout recently)
I made another break out board using a Teensy 4.1 which is also arduino compatible but much faster. I figured this may resolve the lag issues. The Teensy 4.1 has far fewer IO pins than the Mega so I used 1 MCP23017 IO expander on the break out board and I remade the key panel using 4 MCP23017s meant to connect to a separate I2C channel than the 1 on the BOB.
I was going to get help adding the code for this from a friend (I don't really do code myself), when I realized the lag was still too bad to deal with I basically just dropped the whole thing. Now that I see there may be an easy fix for the lag issue I am wondering if there is any chance someone will add the support for I2C IO expanders to this code. I'd like to give this a try again but since I already have a Teensy BOB and boards that use I2C IO expanders, I would prefer to use that.
When I was first testing this, I made a break-out board for an Arduino Mega. I designed a 32key Matrix key panel with LEDs at the same time. When I got that working with Arduino connector, I was not happy with the pulsing effect of the LEDs. I also had pretty bad lag (which seems it may have been resolved with adjusting the serial timeout recently)
I made another break out board using a Teensy 4.1 which is also arduino compatible but much faster. I figured this may resolve the lag issues. The Teensy 4.1 has far fewer IO pins than the Mega so I used 1 MCP23017 IO expander on the break out board and I remade the key panel using 4 MCP23017s meant to connect to a separate I2C channel than the 1 on the BOB.
I was going to get help adding the code for this from a friend (I don't really do code myself), when I realized the lag was still too bad to deal with I basically just dropped the whole thing. Now that I see there may be an easy fix for the lag issue I am wondering if there is any chance someone will add the support for I2C IO expanders to this code. I'd like to give this a try again but since I already have a Teensy BOB and boards that use I2C IO expanders, I would prefer to use that.