aircon/README

   1 Assignment of peripherals and pins
   2 ==================================
   3
   4 TIM1    timing of IR remote control
   5 TIM2    MODBUS timing
   6 TIM3    DS18B20 one-wire bus timing: CH1 drives DMA1, CH2 drives the line
   7 TIM4    PWM: CH1 for fan control, CH2 for IR RC carrier
   8
   9 USART1  debugging
  10 USART3  MODBUS
  11
  12 DMA1    DS18B20 one-wire bus sampling
  13
  14
  15                            Blue Pill pinout
  16                         +--------------------+
  17                         | VBATT         3.3V |
  18 BluePill LED            | PC13           GND |
  19                         | PC14            5V |
  20 bypass opto-coupler     | PC15           PB9 |
  21                         | PA0            PB8 |
  22                         | PA1            PB7 |  TIM4 CH2 - IR LED*
  23                         | PA2            PB6 |  TIM4 CH1 - fan control opto-coupler
  24                         | PA3            PB5 |
  25                         | PA4            PB4 |
  26                         | PA5            PB3 |
  27 RS485 TX enable         | PA6           PA15 |
  28 TIM3_CH2 - DS18B20 bus  | PA7           PA12 |
  29 bypass LED* (green)     | PB0           PA11 |
  30 MODBUS frame LED* (red) | PB1           PA10 |  RXD1 - debugging console
  31 TXD3 - RS485            | PB10           PA9 |  TXD1 - debugging console
  32 RXD3 - RS485            | PB11           PA8 |
  33                         | RESET         PB15 |
  34                         | 3.3 V         PB14 |
  35                         | GND           PB13 |
  36                         | GND           PB12 |
  37                         +--------------------+
  38
  39 Interface connector
  40 ===================
  41
  42         (this side to PCB edge)
  43
  44         heat exchanger +24V
  45         heat exchanger GND
  46         heat exchanger bypass servo
  47         heat exchanger fan control (IN1)
  48         -
  49         temperature sensors VCC
  50         temperature sensors GND
  51         temperature sensors data bus
  52
  53         (this side to BluePill)