1 (MOSI/DI/SDA/!OC1A/PCINT8) PB0 MOSI,LED1 SENSE1+ PA0 (ADC0/DI/SDA/PCINT0)
2 (MISO/DO/OC1A/PCINT9) PB1 MISO,PWM1 SENSE12- PA1 (ADC1/DO/PCINT1)
3 (SCK/USCK/SCL/!OC1B/PCINT10) PB2 SCK,LED2 SENSE2+ PA2 (ADC2/INT1/USCK/SCL/PCINT2)
4 (OC1B/PCINT11) PB3 PWM2 SW2 PA3 (AREF/PCINT3)
7 (ADC7/!OC1D/CLKI/XTAL1/PCINT12) PB4 LED3 SENSE5 PA4 (ADC3/ICP0/PCINT4)
8 (ADC8/OC1D/CLKO/XTAL2/PCINT13) PB5 PWM3 SENSE3+ PA5 (ADC4/AIN2/PCINT5)
9 (ADC9/INT0/T0/PCINT14) PB6 SW1 SENSE34- PA6 (ADC5/AIN0/PCINT6)
10 (ADC10/RESET/PCINT15) PB7 RST SENSE4+ PA7 (ADC6/AIN1/PCINT7)
24 SENSE4 - ambient light sensor
25 SENSE5 - battery voltage sense
27 SW2 - temporary light boost or whatever
28 LED1 - speedometer illumination LED
33 single-ended resolution:
35 differential resolution 8x gain:
37 differential resolution 32x gain:
39 analog input resistance 100 MOhm
53 400 lx == sunset/sunrise
54 10 klx == full daylight
56 need probably 1-1k lux scale