hoverboard-sideboard-hack-GD/docs/GD32F1x0_Firmware_Library_v3.1.0/Examples/TIMER/TIMER2_pwminputcapture

/*!
    \file  readme.txt
    \brief description of the TIMER2 PWM input capture demo
*/

/*
    Copyright (C) 2017 GigaDevice

    2014-12-26, V1.0.0, platform GD32F1x0(x=3,5)
    2016-01-15, V2.0.0, platform GD32F1x0(x=3,5,7,9)
    2016-04-30, V3.0.0, firmware update for GD32F1x0(x=3,5,7,9)
    2017-06-19, V3.1.0, firmware update for GD32F1x0(x=3,5,7,9)
*/

  This demo is based on the GD32150R-EVAL/GD32190R-EVAL board, it shows how to 
use the TIMER peripheral to measure the frequency and duty cycle of an external
signal.
  
  The TIMxCLK frequency is set to systemcoreclock (72MHz), the prescaler is 72
so the TIMER2 counter clock is 1MHz.
  
  The external signal is connected to TIMER2 CH0 pin(PB4). 
  The rising edge is used as active edge.
  The TIMER2 CH0CV is used to compute the frequency value.
  The TIMER2 CH1CV is used to compute the duty cycle value. 

  The minimum frequence of the input signal to measure is 16 Hz.

  You can use USART to watch the frequency and duty cycle of the input signal.
The USART is configured as follow:
  - BaudRate = 115200 baud  
  - Word Length = 8 Bits
  - One Stop Bit
  - No parity
  - Hardware flow control disabled (RTS and CTS signals)
  - Receive and transmit enabled