arducontrol/monitor.c

   1 #include "adc.h"
   2 #include "interface.h"
   3 #include "monitor.h"
   4 #include "output.h"
   5 #include "serial.h"
   6
   7 uint16_t track_current_samples[16] = { 0 };
   8 uint8_t track_current_head = 0;
   9 volatile uint16_t track_current_sum = 0;
  10 uint16_t overcurrent_limit = 8796;
  11 uint8_t overcurrent_sent = 0;
  12
  13 uint16_t input_voltage_samples[16] = { 0 };
  14 uint8_t input_voltage_head = 0;
  15 volatile uint16_t input_voltage_sum = 0;
  16
  17 volatile uint8_t adc_state = 0;
  18 volatile uint16_t adc_value = 0;
  19
  20 uint16_t track_current_milliamps(void);
  21 uint16_t input_voltage_millivolts(void);
  22
  23 void monitor_init(void)
  24 {
  25         adc_init();
  26 }
  27
  28 void monitor_check(void)
  29 {
  30         if(!(adc_state&1))
  31         {
  32                 uint16_t value = adc_value;
  33
  34                 if(adc_state==2)
  35                 {
  36                         uint8_t i = track_current_head;
  37                         track_current_sum -= track_current_samples[i];
  38                         track_current_samples[i] = value;
  39                         track_current_sum += value;
  40                         track_current_head = (i+1)&15;
  41
  42                         if(track_current_sum>overcurrent_limit)
  43                         {
  44                                 output_set_power(0);
  45                                 if(!overcurrent_sent)
  46                                 {
  47                                         overcurrent_sent = 1;
  48                                         interface_send1(OVERCURRENT);
  49                                 }
  50                         }
  51                         else
  52                                 overcurrent_sent = 0;
  53                 }
  54                 else if(adc_state==4)
  55                 {
  56                         uint8_t i = input_voltage_head;
  57                         input_voltage_sum -= input_voltage_samples[i];
  58                         input_voltage_samples[i] = value;
  59                         input_voltage_sum += value;
  60                         input_voltage_head = (i+1)&15;
  61                 }
  62
  63                 adc_state = (adc_state+1)&3;
  64                 adc_read_async(adc_state>>1);
  65         }
  66 }
  67
  68 uint8_t monitor_command(const uint8_t *cmd_buf, uint8_t cmd_length)
  69 {
  70         if(cmd_buf[0]==READ_TRACK_CURRENT)
  71         {
  72                 uint8_t reply[3];
  73
  74                 if(cmd_length!=1)
  75                         return LENGTH_ERROR;
  76
  77                 uint16_t value = track_current_milliamps();
  78                 reply[0] = TRACK_CURRENT;
  79                 reply[1] = value>>8;
  80                 reply[2] = value;
  81                 interface_send(reply, sizeof(reply));
  82         }
  83         else if(cmd_buf[0]==SET_OVERCURRENT_LIMIT)
  84         {
  85                 if(cmd_length!=3)
  86                         return LENGTH_ERROR;
  87
  88                 uint16_t value = (cmd_buf[1]<<8) | cmd_buf[2];
  89                 if(value>4000)  // Safe maximum value
  90                         return INVALID_VALUE;
  91
  92                 // Convert from milliamps: (512+v/1000*0.185/5*1024)*16
  93                 // multiply by 16384*0.185/5000 = 0.1001101100110b
  94                 uint16_t v_3 = value*3;
  95                 overcurrent_limit = 8192+(value>>1)+(v_3>>5)+(v_3>>8)+(v_3>>12);
  96         }
  97         else if(cmd_buf[0]==READ_INPUT_VOLTAGE)
  98         {
  99                 uint8_t reply[3];
 100
 101                 if(cmd_length!=1)
 102                         return LENGTH_ERROR;
 103
 104                 uint16_t value = input_voltage_millivolts();
 105                 reply[0] = INPUT_VOLTAGE;
 106                 reply[1] = value>>8;
 107                 reply[2] = value;
 108                 interface_send(reply, sizeof(reply));
 109         }
 110         else
 111                 return INVALID_COMMAND;
 112
 113         return COMMAND_OK;
 114 }
 115
 116 uint16_t track_current_milliamps(void)
 117 {
 118         uint16_t value = track_current_sum;
 119
 120         // Convert to milliamps: (v/16*5/1024-2.5)*1000/0.185
 121         if(value<8192)  // Ignore negative current readings
 122                 return 0;
 123         else
 124         {
 125                 value -= 8192;
 126
 127                 // multiply by 5000/0.185/16384 = 1.1010011001001b
 128                 int16_t v_3 = value*3;
 129                 return (v_3>>1)+(value>>3)+(v_3>>7)+(value>>10)+(v_3>>13);
 130         }
 131 }
 132
 133 uint16_t input_voltage_millivolts(void)
 134 {
 135         uint16_t value = input_voltage_sum;
 136
 137         // Convert to millivolts: (v/16*5/1024)*1000*11
 138         // multiply by 55000/16384 = 11.0101101101100b
 139         uint16_t v_3 = value*3;
 140         return v_3+(value>>2)+(v_3>>5)+(v_3>>8)+(v_3>>11);
 141 }
 142
 143 static inline void adc_complete(uint16_t value)
 144 {
 145         adc_value = value;
 146         ++adc_state;
 147 }
 148
 149 ADC_SET_CALLBACK(adc_complete)