On kinetis, the TPM_STATUS_TOF was used to detect missed interrupts for
PPM decoding. However this was not correct, because the TOF bit was set on
each timer overflow. This happened regularly after every 64ms interval,
which meant that most PPM frames were just discarded.
I have not found any equivalent register/solution that is used on STMF4,
so this just removes the TOF handling. However there is now no way to
detect missed edges/interrupts!
PX4 Driver for Kinetis uisng just ADC1.
On V3 HW RC00 the USB_VBUS_VALID on pin 36 of the MCU
ADC0_SE16/ADC1_SE22 is bridged to pin 29 ADC1_DP0 and read
there. But because of missing schottky diodes on V3 HW RC00
the signal is true (3.3V) when powered by the Power Module.
This is the PX4 HRT driver fir the Kinetis K family with TPM
timers.
The requirements for use are an input frequency divisible by
N = {2^0-2^7}. To get a 1 MHz frequency. We currently use
the OCSERCLK of 16 MHz /16.
Daniel Agar