[paparazzi-commits] [paparazzi/paparazzi] 82707b: [stm32] F4: fix ppm input timer frequency for TIM2

[GitHub]

  Branch: refs/heads/master
  Home:   https://github.com/paparazzi/paparazzi
  Commit: 82707b869b2e64222d2aaec64988276dcdf4e89e
      
https://github.com/paparazzi/paparazzi/commit/82707b869b2e64222d2aaec64988276dcdf4e89e
  Author: Felix Ruess <address@hidden>
  Date:   2013-07-09 (Tue, 09 Jul 2013)

  Changed paths:
    M sw/airborne/arch/stm32/subsystems/radio_control/ppm_arch.c
    M sw/airborne/arch/stm32/subsystems/radio_control/ppm_arch.h
    M sw/airborne/boards/krooz_sd.h

  Log Message:
  -----------
  [stm32] F4: fix ppm input timer frequency for TIM2

- krooz: don't use TIM2 for PWM
- change to 6 ticks per usec to fit all frequencies
- on the F1 we assume to run at 72MHz for HCLK and both timer clocks
  TIM1 -> APB2 = HCLK = 72MHz
  TIM2 -> 2 * APB1 = 2 * 36MHz = 72MHz
- on the F4 we assume 2 * AHB clock:
  TIM1 -> 2 * APB2 = 168MHz
  TIM2 -> 2 * APB1 = 84MHz

closes #470