fine-tuning the moment at which we re-enable the radio to lower energ…

…y consumption

backtracking.py

@@ -0,0 +1,32 @@
+L_D = 0.000320
+D_D = 0.000677
+L_A = 0.000192
+D_A = 0.000590
+
+backtracking = [
+    0,
+    L_D,
+    D_D+L_A,
+    D_D+D_A+L_D,
+    D_D+D_A+D_D+L_A,
+    D_D+D_A+D_D+D_A+L_D,
+    D_D+D_A+D_D+D_A+D_D+L_A,
+    D_D+D_A+D_D+D_A+D_D+D_A+L_D,
+    D_D+D_A+D_D+D_A+D_D+D_A+D_D+L_A,
+    D_D+D_A+D_D+D_A+D_D+D_A+D_D+D_A+L_D,
+    D_D+D_A+D_D+D_A+D_D+D_A+D_D+D_A+D_D+L_A,
+    D_D+D_A+D_D+D_A+D_D+D_A+D_D+D_A+D_D+D_A+L_D,
+    D_D+D_A+D_D+D_A+D_D+D_A+D_D+D_A+D_D+D_A+D_D+L_A,
+    D_D+D_A+D_D+D_A+D_D+D_A+D_D+D_A+D_D+D_A+D_D+D_A+L_D,
+    D_D+D_A+D_D+D_A+D_D+D_A+D_D+D_A+D_D+D_A+D_D+D_A+D_D+L_A,
+    D_D+D_A+D_D+D_A+D_D+D_A+D_D+D_A+D_D+D_A+D_D+D_A+D_D+D_A+L_D,
+]
+
+output = []
+for (k,v) in enumerate(backtracking):
+    output += ['{0:<27} = {1:>4}; // {2:>7}us'.format('app_vars.backtracking[{0}]'.format(k),int(v*32768.0),int(1000000*v))]
+output = '\n'.join(output)
+
+print output
+
+raw_input('press enter to close.')

project/flashflood_local/flashflood_local.ewp

@@ -176,6 +176,7 @@
           <state>LIGHTPIN_ALLMOTES</state>
           <state>ENABLE_LEDS</state>
           <state>ENABLE_DEBUGPINS</state>
+          <state>LINEAR_TOPOLOGY</state>
         </option>
         <option>
           <name>CCPreprocFile</name>

project/flashflood_testbed_production/flashflood.c

@@ -38,9 +38,9 @@
 #endif
 
 // light sensor
-#define LIGHT_SAMPLE_PERIOD       655  // @32kHz, 655=20.00ms
-#define ONE_HOP_LATENCY            42  // @32kHz,  42= 1.28ms
-#define RADIO_STARTUP_DURATION     30  // @32kHz,  30= 1.00ms
+#define LIGHT_SAMPLE_PERIOD       655  // @32kHz, 655=20.000ms
+#define ONE_HOP_LATENCY            42  // @32kHz,  42= 1.280ms
+#define BACKTRACK_TUNING           41  // measured
 
 #ifdef LOCAL_SETUP
     #define SENSING_RADIO_OSC_SCHEDULE_TO_TURNON_OFFSET 29+5 // turn on oscillator a little later than hop 1, so hop 1 could hear the packet
@@ -119,6 +119,7 @@ typedef struct {
     uint8_t             cc2420_panid[2];
     uint8_t             cc2420_ieeeadr[16];
     uint16_t            hopping_sequence[16];
+    uint16_t            backtracking[16];
 } app_vars_t;
 
 app_vars_t app_vars;
@@ -182,6 +183,24 @@ int main(void) {
     app_vars.hopping_sequence[0x0f] = FREQUENCY_4; // ===
 #endif
 
+    //DO NOT EDIT DIRECTLY. Generated by backtracking.py script
+    app_vars.backtracking[0]    =    0; //       0us
+    app_vars.backtracking[1]    =   10; //     320us
+    app_vars.backtracking[2]    =   28; //     869us
+    app_vars.backtracking[3]    =   52; //    1586us
+    app_vars.backtracking[4]    =   69; //    2136us
+    app_vars.backtracking[5]    =   93; //    2853us
+    app_vars.backtracking[6]    =  111; //    3403us
+    app_vars.backtracking[7]    =  135; //    4121us
+    app_vars.backtracking[8]    =  153; //    4670us
+    app_vars.backtracking[9]    =  176; //    5388us
+    app_vars.backtracking[10]   =  194; //    5937us
+    app_vars.backtracking[11]   =  218; //    6654us
+    app_vars.backtracking[12]   =  236; //    7203us
+    app_vars.backtracking[13]   =  259; //    7922us
+    app_vars.backtracking[14]   =  277; //    8471us
+    app_vars.backtracking[15]   =  301; //    9189us
+
     //===== fire up board
 
     // disable watchdog timer
@@ -607,6 +626,7 @@ void timer_b_cb_endFrame(uint16_t timestamp_timerA, uint16_t timestamp_timerB){
     uint16_t       newCompareValue;
     uint8_t        crcByte;
     uint8_t        i;
+    uint8_t        my_hop;
     //uint8_t        reg_FSCTRL_byte0;
 
     // determine when I've just receive a packet for me
@@ -892,13 +912,15 @@ void timer_b_cb_endFrame(uint16_t timestamp_timerA, uint16_t timestamp_timerB){
     newCompareValue          = timestamp_timerA;
     newCompareValue         += LIGHT_SAMPLE_PERIOD;
     if (rxpkt_len==FRAME_ACK_LEN) {
-        // when I receive an ACK frame, I'm at at depth rx_hop+2
-        newCompareValue     -= (rx_hop+2)*ONE_HOP_LATENCY;
+        my_hop               = rx_hop+2;
     } else {
-        // when I receive a DATA frame, I'm at at depth rx_hop+1
-        newCompareValue     -= (rx_hop+1)*ONE_HOP_LATENCY;
+        my_hop               = rx_hop+1;
+    }
+    if (my_hop>16) {
+        my_hop               = 16;
     }
-    newCompareValue         -=  RADIO_STARTUP_DURATION;
+    newCompareValue         -=  app_vars.backtracking[my_hop];
+    newCompareValue         -=  BACKTRACK_TUNING;
 
     TACCR2   =  newCompareValue;
     TACCTL2  =  CCIE;