ppm_to_hoverboard_uart.c

#define debug 0
#define deadband 50

#define nchannels 4
typedef struct{
   int16_t steer;
   int16_t speed;
} Serialcommand;

volatile Serialcommand command;

void setup() {
  for(int i=2;i<=5;i++)pinMode(i,INPUT);
  if(!debug)Serial.begin(19200);
  if(debug)Serial.begin(115200);
}

bool read_d(uint8_t i){
  return PIND & (1 << i);
}

void loop() {
  uint32_t timeout=0;
  int channels[nchannels]={0,0,0,0};
  for(uint8_t i=2;i<2+nchannels;i++){
    while(read_d(i)!=0 && timeout<300000)timeout++;
    while(read_d(i)!=1 && timeout<300000)timeout++;
    long start=micros();
    while(read_d(i)!=0 && timeout<300000)timeout++;
    long end=micros();
    channels[i-2]=end-start;
  }


  if(timeout>=300000){
    for(uint8_t i=0;i<nchannels;i++)channels[i]=0;
  }
  for(uint8_t i=0;i<nchannels;i++){
    if(debug)Serial.print(i);
    if(debug)Serial.print(": ");
    if(debug)Serial.println(channels[i]);
  }
  int mult=channels[2]-1100;
  mult*=2.2;
  if(mult>1000)mult=1000;
  if(mult<0)mult=0;

  int32_t speed=channels[1]-1500;
  speed*=2.5;
  if(speed>0 && speed<deadband)speed=0;else if(speed>0)speed-=deadband;
  if(speed<0 && speed>-deadband)speed=0;else if(speed<0)speed+=deadband;
  speed*=mult;
  speed/=1000;
  if(speed>1000)speed=1000;
  if(speed<-1000)speed=-1000;
  command.speed=speed;

  int32_t steer=channels[0]-1500;
  steer*=2.5;
  if(steer>0 && steer<deadband)steer=0;else if(steer>0)steer-=deadband;
  if(steer<0 && steer>-deadband)steer=0;else if(steer<0)steer+=deadband;
  steer*=mult;
  steer/=1000;
  if(steer>1000)steer=1000;
  if(steer<-1000)steer=-1000;
  steer=-steer;
  command.steer=steer;


  if(channels[2]<1150 && channels[3]<1050 && channels[2]>1000 && channels[3]>1000){
    //poweroff
    command.speed=0;
    command.steer=0;
    //handle custom poweroff routine, i.e. by writing magic numbers to the boards (require firmware modification)
  }
  
  if(debug)Serial.println(timeout);
  if(debug)Serial.println(command.speed);
  if(debug)Serial.println(command.steer);

  
  if(!debug)Serial.write((uint8_t *) &command.steer, sizeof(command.steer)); 
  if(!debug)Serial.write((uint8_t *) &command.speed, sizeof(command.speed));
}

contact me by mail [email protected] Thank you in advance.

Hello Peter. Can you help me? My problem is that I can't properly program my Flipsky MX4 PPM remote control to the hoverboard board.

Hey, where you able to get it to work? I have the same issue with frsky