Cannot change I2C address of the Adafruit Mini I2C STEMMA QT Gamepad about adafruit_seesaw

[caternuson]

Was able to recreate this. The issue is the hardwired value of 0x3F for SEESAW_EEPROM_I2C_ADDR here:

Adafruit_Seesaw/Adafruit_seesaw.h

Lines 202 to 204 in c3e7b8f

	#define SEESAW_EEPROM_I2C_ADDR \
	0x3F ///< EEPROM address of i2c address to start up with (for devices that
	///< support this feature)

That's the correct location for SAMD based seesaw firmware:
https://github.com/adafruit/seesaw/blob/af364d5bcd24330fbb00d9c34e6b27f090af7ab3/include/RegisterMap.h#L215

However, for ATtiny based seesaw firmware, the location is the end of EEPROM, which is determined dynamically:
https://github.com/adafruit/Adafruit_seesawPeripheral/blob/12dd2e85d294eee182922d6cc544f17bb30ef19a/Adafruit_seesawPeripheral.h#L26
The EEPROM address location ends up being 0x7F on ATtiny816 used on GamePad. (ATtiny16xx's would be 0xFF)

So this library is reading/writing to the incorrect EEPROM location for any ATtiny based seesaw product.

[pongsagon]

Thanks I can change the I2C address now.

Adafruit_seesaw ss;
...
uint8_t newAddress = 0x49;
ss.EEPROMWrite8(0x7F, newAddress);
delay(250);
ss.begin(newAddress); // now return true and can read the input