Timer one shot

This is a specific setting of input and output capture mode. The counter starts in response to a stimulus and then generates a pulse of specific length after a specific delay.

   Delay = CCRy / (TIMx_CLK / (PSC + 1))
   Pulse length = (ARR - CCRy) / (TIMx_CLK / (PSC + 1))

###To configure:

1. confgure input pin and mode

• select TIxFPx trigger to be used
  • in CCMRx reg - write CCxS bits
• select polarity of input (pos, neg, both)
  • in CCER reg - write CCxP and CCxNP bits
• configure TIxFPx trigger to slave mode
  • in SMCR reg - write TS bits
• select trigger mode to slave mode
  • in SMCR reg - write SMS bits

2. configure output pin and mode

• select output polarity - in CCER reg - write CCyP bit
• select output compare mode
  • in CCMRy reg - write OCyM bits
  • PWM1 or PWM2 mode
• set delay value
  • in CCRy reg - write delay value
• set autoreload to have desired pulse
• pulse = TIMy_ARR - TIMy_CCRy

3. select one-pulse mode if only need one pulse (else reset bit)

• in CR1 reg - set OPM bit