Just checking if I am reading the datasheet right. I am using I2C from an ATTiny85 to send data to an UNO, no problems there, and since I had an extra pin and some analog temperature sensors I thought I'd send that data too. OK, the Microchip MCP9700 has a straight analog output of 10mv/C degree, with a base of 500mv at 0 degrees C. Still no problem, reads and transmits the raw data fine, but I would like to use the internal 1.1V reference voltage to increase the sensitivity. Now the problem: page 62 "PBO = MOSI:: SPI Master Data Output / Slave Data Input AIN0: Analog Comparator, Positive Input OC0A: Timer/Counter0 Compare Match A output OC1A: Complementary Timer/Counter1 Compare Match A Output DI: USI Data Input (Three Wire Mode) SDA: USI Data Input (Two Wire Mode) AREF: External Analog Reference PCINT0: Pin Change Interrupt 0, Source 0"
AND page 64
" AREF: External Analog Reference for ADC. Pullup and output driver are disabled on PB0 when the pin is used as an external reference or Internal Voltage Reference with external capacitor at the AREF pin."
SO.... setting the internal analog reference will NOT work if I am using I2C, correct? Don't really need the accuracy, but it would be nice to get it to work. Thanks , TomJ