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(g_index_to_gpio[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(g_index_to_gpio[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_BOOL_T},
  61                 {"pol", &pol, FCGI_BOOL_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                 POL,
  72                 FREQ,
  73                 DUTY
  74         } SensorParams;
  75
  76         // Fill values appropriately
  77         if (!FCGI_ParseRequest(context, params, values, sizeof(values)/sizeof(FCGIValue)))
  78         {
  79                 // Error occured; FCGI_RejectJSON already called
  80                 return;
  81         }
  82
  83         Log(LOGDEBUG, "Params: type = %s, num = %d, set = %d, pol = %d, freq = %f, duty = %f", type, num, set, pol, freq, duty);
  84
  85         if (strcmp(type, "gpo") == 0)
  86         {
  87                 if (num <= 0 || num > GPIO_NUM_PINS)
  88                 {
  89                         FCGI_RejectJSON(context, "Invalid GPIO pin");
  90                         return;
  91                 }
  92
  93                 Log(LOGDEBUG, "Setting GPIO%d to %d", num, set);
  94                 GPIO_Set(num, set);
  95
  96                 FCGI_PrintRaw("Content-type: text/plain\r\n\r\n");
  97                 FCGI_PrintRaw("GPIO%d set to %d\n", num, set);
  98         }
  99         else if (strcmp(type, "gpi") == 0)
 100         {
 101                 if (num < 0 || num >= GPIO_NUM_PINS)
 102                 {
 103                         FCGI_RejectJSON(context, "Invalid GPIO pin");
 104                         return;
 105                 }
 106                 Log(LOGDEBUG, "Reading GPIO%d", num);
 107                 FCGI_PrintRaw("Content-type: text/plain\r\n\r\n");
 108                 FCGI_PrintRaw("GPIO%d reads %d\n", num, GPIO_Read(num));
 109
 110         }
 111         else if (strcmp(type, "adc") == 0)
 112         {
 113                 if (num < 0 || num >= ADC_NUM_PINS)
 114                 {
 115                         FCGI_RejectJSON(context, "Invalid ADC pin");
 116                         return;
 117                 }
 118                 Log(LOGDEBUG, "Reading ADC%d", num, set);
 119                 FCGI_PrintRaw("Content-type: text/plain\r\n\r\n");
 120                 FCGI_PrintRaw("ADC%d reads %d\n", num, ADC_Read(num));
 121         }
 122         else if (strcmp(type, "pwm") == 0)
 123         {
 124                 if (num < 0 || num >= PWM_NUM_PINS)
 125                 {
 126                         FCGI_RejectJSON(context, "Invalid PWM pin");
 127                         return;
 128                 }
 129
 130                 FCGI_PrintRaw("Content-type: text/plain\r\n\r\n");
 131
 132                 if (set)
 133                 {
 134                         Log(LOGDEBUG, "Setting PWM%d", num);
 135                         duty = duty < 0 ? 0 : duty > 1 ? 1 : duty;
 136                         long period_ns = (long)(1e9 / freq);
 137                         long duty_ns = (long)(duty * period_ns);
 138                         PWM_Set(num, pol, period_ns, duty_ns);
 139                         FCGI_PrintRaw("PWM%d set to period_ns = %lu (%f Hz), duty_ns = %lu (%f), polarity = %d",
 140                                 num, period_ns, freq, duty_ns, duty*100, (int)pol);
 141                 }
 142                 else
 143                 {
 144                         Log(LOGDEBUG, "Stopping PWM%d",num);
 145                         PWM_Stop(num);
 146                         FCGI_PrintRaw("PWM%d stopped",num);
 147                 }
 148         }
 149         else
 150         {
 151                 Log(LOGDEBUG, "Invalid pin type %s", type);
 152                 FCGI_RejectJSON(context, "Invalid pin type");
 153         }
 154
 155
 156
 157 }
 158
 159 //EOF