BBB code/ActuatorHandler_real.c

   1 void ActuatorHandler(FCGIContext *context, ActuatorId id, const char *set_value) {
   2         char *ptr;
   3
   4         switch(id) { //Add new actuators here
   5                 case ACT_PRESSURE: //Suppose is pressure regulator. 0-700 input (kPa)
   6                 //requires PWM control
   7                 //TBA, currently in a separate file
   8                 //pwm_convert_duty(value); - convert input to required duty cycle
   9                 //pwm_set_frequency(PWM_id, freq); - can be done during PWM setup, frequency won't change (50Hz?)
  10                 //pwm_set_duty_cycle(PWM_id, duty_cycle); - this is the low/high percentage, will vary with input
  11                 //may also need to set polarity?
  12                 //if pwm is not setup, run setup functions first
  13                 {
  14                         int value = strtol(set_value, &ptr, 10);
  15                         if (*ptr == '\0' && value >= 0 && value <= 700) {
  16                                 FCGI_BeginJSON(context, STATUS_OK);
  17                                 FCGI_JSONKey("description");
  18                                 FCGI_JSONValue("\"Set pressure to %d kPa!\"", value);
  19                                 FCGI_EndJSON();
  20                         } else {
  21                                 FCGI_RejectJSONEx(context,
  22                                         STATUS_ERROR, "Invalid pressure specified.");
  23                         }
  24                 } break;
  25                 case ACT_SOLENOID1:
  26                 //requires digital control
  27                 {
  28                         int value = strtol(set_value, &ptr, 10);
  29                         if (*ptr == '\0') {
  30                                 //code to set pin to value
  31                                 //move this to separate function, will need to be repeated
  32                                 int fd;
  33                                 char buffer[10];
  34                                 if ((fd = open("/sys/class/gpio/gpio50/value", O_WRONLY)) < 0)  //randomly chose pin 50 (each pin can be mapped to a certain switch case as required)
  35                                         perror("Failed to open pin");
  36                                 if (value) {
  37                                         strncpy(buffer, "1", ARRAY_SIZE(buffer) - 1);                           //copy value to buffer
  38                                 } else {
  39                                         strncpy(buffer, "0", ARRAY_SIZE(buffer) - 1);
  40                                 }
  41                                 int write = write(fd, buffer, strlen(buffer));                                  //write buffer to pin
  42                                 if (write < 0) perror("Failed to write to pin");
  43                                 close(fd);
  44                                 //code for server
  45                                 const char *state = "off";
  46                                 if (value)
  47                                         state = "on";
  48                                 FCGI_BeginJSON(context, STATUS_OK);
  49                                 FCGI_JSONKey("description");
  50                                 FCGI_JSONValue("\"Solenoid 1 turned %s!\"", state);
  51                                 FCGI_EndJSON();
  52                         } else {
  53                                 FCGI_RejectJSON(context, "Invalid actuator value specified");
  54                         }
  55                 } break;
  56                 default:
  57                         FCGI_RejectJSONEx(context,
  58                                 STATUS_ERROR, "Invalid actuator id specified.");
  59         }
  60 }