HITCON PCB Badge

Firmware Development

execute fw/merge.py to merge STM32CubeIDE generated main.c with user code in main.cc into main.cc.

Timers and DMA Channels

• IR Tx: PWM Output from TIM3_CH3, Output PB0, DMA1 Ch2
  • Compare: 63/4 = 16
  • Mode: Circular Normal Peripheral to Memory

	Peripheral	Memory
Increment Address	X	V
Data Width	Half Word	Half Word

• IR Rx: DMA Triggered through TIM2_CH3, Input PA0 read by DMA1 Ch1
  • Compare: 105
  • Mode: Circular Peripheral to Memory

	Peripheral	Memory
Increment Address	X	V
Data Width	Half Word	Half Word

• Led Rows/Cols: DMA Triggered through TIM1_UP, Output PB6-9(Rows), Output PB1-2/10-15(Cols), written by DMA1 Ch5
  • Mode: Circular Memory to Peripheral

	Peripheral	Memory
Increment Address	X	V
Data Width	Word	Word

• Led Brightness control: PWM Output from TIM3_CH2
• Buttons: Reads Input PA4-10, PA15 through TIM4_CH2, DMA1 Ch4
  • Compare: 5
  • Mode: Circular Peripheral to Memory

	Peripheral	Memory
Increment Address	X	V
Data Width	Half Word	Half Word

• Cross-board communication TX: USART2 TX, DMA1 Ch7

• Cross-board communication RX: USART2 RX, DMA1 Ch6

• TIM4: Operates at 100Hz for Button

  • Prescaler: 12000-1
  • Counter Period: 10-1

• TIM3: Operates at 38kHz for PWM out.

  • Prescaler: 5-1
  • Counter Period: 63-1
  • Master Mode Enable

• TIM2:

  • Prescaler: 0
  • Counter Period: 4-1
  • Slave Mode: External Clock
  • Trigger Source: ITR2 (TIM3 Update Event)
  • Operates at 1/4 speed of TIM3, synchronization needed for IR pulse alignment and brightness adjustment.
  • Also operates at 1/4 bit time for capturing IR.
  • TIM2 = 38/4 kHz = 9.5kHz.
  • Bit time = 4/9.5kHz = 421us (each bit is 16 pulse).

• TIM1:

  • Prescaler: 5-1
  • Counter Period: 1500-1
  • LED refreshes at 3200/16 = 200Hz.

Format

To check format, please install clang-format first.

# under hitcon-pcb-badge
./lint.sh # check format
./lint.sh -i # auto format