Diff: main.cpp

Revision:

16:dcc5f9075595

Parent:

15:cfc7d817e444

Child:

17:7093a533b4ae

--- a/main.cpp	Fri Aug 12 03:34:51 2016 +0000
+++ b/main.cpp	Tue Aug 23 04:50:45 2016 +0000
@@ -20,9 +20,22 @@
 InterruptIn button(USER_BUTTON);
 
 // sensors
-#define SUPPLY_VOLTAGE 3.3;
+#define SUPPLY_VOLTAGE 3.3f;
 AnalogIn TempSensor(PA_0);
 
+// convert fp32 to 4 byte string
+typedef union
+{
+    float fp32;
+    uint8_t bytes[4];
+} float_bytes_32;
+
+typedef union
+{
+    int16_t int16;
+    uint8_t bytes[2];
+} int_string_16;
+
 float getTemperature() 
 {
     float reading = TempSensor.read();
@@ -67,6 +80,42 @@
     return 0;
 }
 
+int queryServiceQuality(uint8_t *payload, uint8_t payload_length, uint8_t *response, uint8_t *response_length)
+{
+    // decode user message
+    uint8_t node_id = payload[0];
+    
+    // create a command packet
+    ControlPacket packet;
+    
+    // layer 3 sequence id is not used in this case
+    packet.setSequenceID(0x0);
+    
+    // set source id as current device id
+    packet.setSourceID(aloha.getDeviceID());
+    
+    // set destination id as node id
+    packet.setDestinationID(node_id);
+    
+    // set command as query (0x03)
+    packet.setCommand(0x03);
+    
+    // generate crc
+    packet.generateCrc();
+    
+    // create buffer for transmission
+    uint8_t buffer[8];
+    memset(buffer, 0x0, sizeof(buffer));
+    
+    // copy bytes into buffer
+    packet.serialize(buffer);
+    
+    // send to aloha transceiver
+    aloha.send(buffer, 8, node_id);
+    
+    return 0;
+}
+
 /*
  * Format: 
  * <        :start flag
@@ -450,10 +499,82 @@
                     
                     break;
                 }
+                
+                case 0x2:                   // received response for service quality
+                {
+                    uint8_t payload[6];
+                    
+                    // first byte is the snr of foreign host
+                    payload[0] = controlPacket.getData(0);
+                    
+                    // second and third byte are the rssi of foreign host
+                    payload[1] = controlPacket.getData(1);
+                    payload[2] = controlPacket.getData(2);
+                    
+                    // fourth byte is the snr of local host
+                    payload[3] = (uint8_t) aloha.getSnr();
+                    
+                    // fifth and sixth byte are the rssi of local host
+                    int_string_16 rssi;
+                    rssi.int16 = aloha.getRssi();
+                    
+                    payload[4] = rssi.bytes[0];
+                    payload[5] = rssi.bytes[1];
+                    
+                    // make response
+                    SIP.respond(0xf1, payload, 3);
+                    
+                    break;   
+                }
+                case 0x3:                  // respond for service quality
+                {
+                    int_string_16 rssi;
+                    uint8_t snr;
+                    
+                    // get rssi and snr
+                    rssi.int16 = aloha.getRssi();
+                    snr = aloha.getSnr();
+                    
+                    // create response
+                    ControlPacket response;
+                    
+                    // set layer 3 sequence id
+                    response.setSequenceID(0x0);
+                    
+                    // set source id
+                    response.setSourceID(aloha.getDeviceID());
+                    
+                    // set destination id
+                    response.setDestinationID(src_addr);
+                    
+                    // set command as respond
+                    response.setCommand(0x2);
+                    
+                    // set payload
+                    response.setData(0, (uint8_t) snr);         // store SNR
+                    response.setData(1, (uint8_t) rssi.bytes[0]);   // store higher bits of RSSI
+                    response.setData(2, (uint8_t) rssi.bytes[1]);   // store lower bits of RSSI
+                
+                    // generate crc
+                    packet.generateCrc();
+                    
+                    // create buffer for transmission
+                    uint8_t buffer[8];
+                    memset(buffer, 0x0, sizeof(buffer));
+                    
+                    // copy bytes into buffer
+                    packet.serialize(buffer);
+                    
+                    // send to aloha transceiver
+                    aloha.send(buffer, 8, src_addr);
+                    
+                    break;
+                }
+                
                 default:
                     break;
             }
-                
+            
             break;
         }
         case BasicPacket::L3DataBlockPacket:
@@ -500,7 +621,7 @@
     
     // register callback functions for SIP
     SIP.registerCommand(0x00, toggleChecksum);
-    SIP.registerCommand(0x01, NULL);                // disable sendMessage for now
+    SIP.registerCommand(0x01, queryServiceQuality);
     SIP.registerCommand(0x02, configureRadio);
     SIP.registerCommand(0x03, radioUpdateSettings);