Looking at the schematics for LED, Green and Red are connected to PORTA and Blue is connected to PORTB of MCP23017.
But in the code LiquidTWI2::setBacklight(), burstBits16 is being called which is sending to PORTA in two separate 8 bits.
Does it not just override the first write and Blue in PORTB is not even triggered?
Should it not be, writing only the first 8 bits to PORTA and the next 8 bits to PORTB.
Sorry if i don't understand it correctly, but could someone help me out.
The V2 LED hardware works just fine. Blue is triggered without issue.
Someone with more knowledge of LiquidTWI2 will have to explain the code.