1 ATTiny 861A pin assignment
2 ==========================
3 (MOSI/DI/SDA/!OC1A/PCINT8) PB0 MOSI,LED4 SENSE1+ PA0 (ADC0/DI/SDA/PCINT0)
4 (MISO/DO/OC1A/PCINT9) PB1 MISO,PWM1 SENSE12- PA1 (ADC1/DO/PCINT1)
5 (SCK/USCK/SCL/!OC1B/PCINT10) PB2 SCK,LED5 SENSE2+ PA2 (ADC2/INT1/USCK/SCL/PCINT2)
6 (OC1B/PCINT11) PB3 PWM2 LED6 PA3 (AREF/PCINT3)
9 (ADC7/!OC1D/CLKI/XTAL1/PCINT12) PB4 SW2 LED7 PA4 (ADC3/ICP0/PCINT4)
10 (ADC8/OC1D/CLKO/XTAL2/PCINT13) PB5 PWM3 SENSE3 PA5 (ADC4/AIN2/PCINT5)
11 (ADC9/INT0/T0/PCINT14) PB6 SW1 SENSE4 PA6 (ADC5/AIN0/PCINT6)
12 (ADC10/RESET/PCINT15) PB7 RST SENSE5 PA7 (ADC6/AIN1/PCINT7)
17 PWM1 LED1 rear spotlight: step-down, differential SENSE1
18 PWM2 LED2 rear LED strip: step-up, differential SENSE2
19 PWM3 LED3 front light: step-down, single-ended SENSE3, inverted stride
21 SENSE4 - ambient light sensor, single-ended
22 SENSE5 - battery voltage sensor, single-ended
24 LED4 - status LED (green)
25 LED5 - error LED (red)
27 LED6 - speedometer illumination LED
30 SW1 - on/off; mode switch
31 SW2 - temporary light boost or whatever
35 ======== 0.033R sensign res.
36 single-ended resolution: 0.001074 V .. 1.1000 V 32.55 .. 33333 mA
37 differential resolution 8x gain: 0.000134 V .. 0.1375 V 4.06 .. 4166 mA
38 differential resolution 20x gain: 0.000054 V .. 0.0550 V 1.64 .. 1666 mA
39 differential resolution 32x gain: 0.000036 V .. 0.0344 V 1.09 .. 1042 mA
41 analog input resistance 100 MOhm
46 0.033R sensing resistor:
51 300 mA => 0.0099 V Power burned at sensing resistor:
52 350 mA => 0.0116 V 0.004 W
53 700 mA => 0.0231 V 0.016 W
54 1000 mA => 0.0330 V 32x 0.033 W
55 1500 mA => 0.0495 V 20x 0.074 W
56 2000 mA => 0.0660 V 8x 0.132 W
57 3000 mA => 0.0990 V 8x 0.297 W
64 voltage current sense voltage
71 5 V, 1M5 resistor + photodiode: voltage at the photodiode
72 darkness: 3.71 V => 4.31 MOhm
73 bathroom without lights, only outside lights: 3.68 V => 4.18 MOhm
74 kitchen light: 3.29 V => 2.89 MOhm
75 room 30min before midnight: 0.26 V => 82 KOhm
76 outside 30min before midnight: 0.05 V => 15 KOhm
77 bathroom halogen lights 0.02 V => 6 KOhm
78 battery light: 0.01 V => 3 KOhm
80 Use 1M5 main resistor + 300K sensing resistor, 1.1V single-ended sense
82 Expected voltage ADC readings
83 darkness: 0.244 V 226.8
84 bathroom: 0.249 V 231.8
85 kitchen light: 0.318 V 296.2
86 halogen light: 0.831 V 773.1
87 battery light: 0.832 V 774.5
92 20 mA/3V: 100 R resistor
93 20 mA/2V: 150 R resistor
98 2000 mAh: 1.0 mA -> 83 days capacity
99 2000 mAh: 0.1 mA -> 833 days capacity
103 step-up: 4-5 adc measurements to ADC voltage increase
104 step-down 2: 1-2 ---""---
105 timer: 34-38 ADC measurements per jiffy (200 Hz)