server/pin_test.c

   1 /**
   2  * @file pin_test.c
   3  * @purpose Implementations to allow direct control over pins through FastCGI
   4  */
   5
   6 #include "pin_test.h"
   7
   8 #include "bbb_pin.h"
   9
  10 /**
  11  * Export *ALL* pins for control
  12  */
  13 void Pin_Init()
  14 {
  15         for (int i = 0; i < GPIO_NUM_PINS; ++i)
  16                 GPIO_Export(i);
  17
  18         for (int i = 0; i < ADC_NUM_PINS; ++i)
  19                 ADC_Export();
  20
  21         for (int i = 0; i < PWM_NUM_PINS; ++i)
  22                 PWM_Export(i);
  23 }
  24
  25 /**
  26  * Unexport all pins
  27  */
  28 void Pin_Close()
  29 {
  30         for (int i = 0; i < GPIO_NUM_PINS; ++i)
  31                 GPIO_Unexport(i);
  32
  33         for (int i = 0; i < ADC_NUM_PINS; ++i)
  34                 ADC_Unexport(i);
  35
  36         for (int i = 0; i < PWM_NUM_PINS; ++i)
  37                 PWM_Unexport(i);
  38 }
  39
  40 /**
  41  * Handle a request to the Pin test module
  42  * @param context - The FastCGI context
  43  * @param params - key/value pair parameters as a string
  44  */
  45 void Pin_Handler(FCGIContext *context, char * params)
  46 {
  47
  48         char * type = NULL;
  49         int num = 0;
  50         bool set = true;
  51         bool pol = false;
  52         double freq = 50;
  53         double duty = 0.5;
  54
  55
  56         // key/value pairs
  57         FCGIValue values[] = {
  58                 {"type", &type, FCGI_REQUIRED(FCGI_STRING_T)},
  59                 {"num", &num, FCGI_REQUIRED(FCGI_INT_T)},
  60                 {"set", &set, FCGI_INT_T},
  61                 {"pol", &pol, FCGI_INT_T},
  62                 {"freq", &freq, FCGI_DOUBLE_T},
  63                 {"duty", &duty, FCGI_DOUBLE_T}
  64         };
  65
  66         // enum to avoid the use of magic numbers
  67         typedef enum {
  68                 TYPE,
  69                 NUM,
  70                 SET,
  71                 FREQ,
  72                 DUTY
  73         } SensorParams;
  74
  75         // Fill values appropriately
  76         if (!FCGI_ParseRequest(context, params, values, sizeof(values)/sizeof(FCGIValue)))
  77         {
  78                 // Error occured; FCGI_RejectJSON already called
  79                 return;
  80         }
  81
  82         Log(LOGDEBUG, "Params: type = %s, num = %d, set = %d, pol = %d, freq = %f, duty = %f", type, num, set, pol, freq, duty);
  83
  84         if (strcmp(type, "gpo") == 0)
  85         {
  86                 if (num <= 0 || num > GPIO_NUM_PINS)
  87                 {
  88                         FCGI_RejectJSON(context, "Invalid GPIO pin");
  89                         return;
  90                 }
  91
  92                 Log(LOGDEBUG, "Setting GPIO%d to %d", num, set);
  93                 GPIO_Set(num, set);
  94
  95                 FCGI_PrintRaw("Content-type: text/plain\r\n\r\n");
  96                 FCGI_PrintRaw("GPIO%d set to %d\n", num, set);
  97         }
  98         else if (strcmp(type, "gpi") == 0)
  99         {
 100                 if (num < 0 || num >= GPIO_NUM_PINS)
 101                 {
 102                         FCGI_RejectJSON(context, "Invalid GPIO pin");
 103                         return;
 104                 }
 105                 Log(LOGDEBUG, "Reading GPIO%d", num);
 106                 FCGI_PrintRaw("Content-type: text/plain\r\n\r\n");
 107                 FCGI_PrintRaw("GPIO%d reads %d\n", num, GPIO_Read(num));
 108
 109         }
 110         else if (strcmp(type, "adc") == 0)
 111         {
 112                 if (num < 0 || num >= ADC_NUM_PINS)
 113                 {
 114                         FCGI_RejectJSON(context, "Invalid ADC pin");
 115                         return;
 116                 }
 117                 Log(LOGDEBUG, "Reading ADC%d", num, set);
 118                 FCGI_PrintRaw("Content-type: text/plain\r\n\r\n");
 119                 FCGI_PrintRaw("ADC%d reads %d\n", num, ADC_Read(num));
 120         }
 121         else if (strcmp(type, "pwm") == 0)
 122         {
 123                 if (num < 0 || num >= PWM_NUM_PINS)
 124                 {
 125                         FCGI_RejectJSON(context, "Invalid PWM pin");
 126                         return;
 127                 }
 128
 129                 FCGI_PrintRaw("Content-type: text/plain\r\n\r\n");
 130
 131                 if (set)
 132                 {
 133                         Log(LOGDEBUG, "Setting PWM%d", num);
 134                         long period_ns = (long)(1e9 / freq);
 135                         long duty_ns = (long)(duty * period_ns);
 136                         PWM_Set(num, pol, period_ns, duty_ns);
 137                         FCGI_PrintRaw("PWM%d set to period_ns = %lu (%f Hz), duty_ns = %lu (%d), polarity = %d", num, period_ns, freq, duty_ns, duty*100, pol);
 138                 }
 139                 else
 140                 {
 141                         Log(LOGDEBUG, "Stopping PWM%d",num);
 142                         PWM_Stop(num);
 143                         FCGI_PrintRaw("PWM%d stopped",num);
 144                 }
 145         }
 146         else
 147         {
 148                 Log(LOGDEBUG, "Invalid pin type %s", type);
 149                 FCGI_RejectJSON(context, "Invalid pin type");
 150         }
 151
 152
 153
 154 }
 155
 156 //EOF