![](/media/cache/group/default_image.jpg.50x50_q85.jpg)
a
Dependencies: mbed
Fork of GIMBAL_SAMPLE4_PPM by
Diff: PPM/PPMOut.cpp
- Revision:
- 0:f0b20f502059
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/PPM/PPMOut.cpp Thu May 24 10:19:44 2018 +0000 @@ -0,0 +1,63 @@ +#include "mbed.h" +#include "PPMOut.h" + +PpmOut::PpmOut(PinName pin, uint8_t channel_number): ppm(pin) { + if(channel_number > MAX_CHANNELS){ + this->channel_number = MAX_CHANNELS; + } + this->channel_number = channel_number; + resetChannels(); + pulse_out = 1; + ppm = pulse_out; + current_dot = 0; + timeout.attach_us(this, &PpmOut::attimeout, FRAME_LEN); +} + +void PpmOut::setChannel(int channel_no, uint16_t value) { + //__disable_irq(); // Disable Interrupts + if(channel_no > channel_number-1){ + return; + } + if(value > MAX_CHANNEL_VALUE){ + value = MAX_CHANNEL_VALUE; + } + dots[channel_no*2] = CHANNEL_SYNC; + dots[channel_no*2+1] = CHANNEL_PAD_SYNC + value; + + setFrameSync(); + //__enable_irq(); // Enable Interrupts +} + +void PpmOut::setFrameSync(){ + uint16_t sum_channels = 0; + for(uint8_t channel = 0; channel < channel_number; channel++) { + sum_channels += dots[channel*2+1]; + } + sum_channels += channel_number*CHANNEL_SYNC; + dots[channel_number*2] = CHANNEL_SYNC; + dots[channel_number*2+1] = FRAME_LEN - CHANNEL_SYNC - sum_channels; +} + +void PpmOut::attimeout() { + pulse_out = !pulse_out; + ppm = pulse_out; + + timeout.attach_us(this, &PpmOut::attimeout, dots[current_dot]); + current_dot++; + + if(current_dot == channel_number*2+2) { // 2 for FRAME_SYNC + current_dot = 0; + } +} + +void PpmOut::resetChannels() { + int8_t channel; + + current_dot = 0; + memset(dots, 0x00, DOTS); + for(channel = 0; channel < channel_number; channel++) { + dots[channel*2] = CHANNEL_SYNC; + dots[channel*2+1] = CHANNEL_PAD_SYNC; + } + setFrameSync(); +} \ No newline at end of file