Diff: xbee900hp.cpp

Revision:

2:7f4ddf710a44

Parent:

1:b97d46c5d7ce

Child:

3:3c3707b0f5cd

--- a/xbee900hp.cpp	Wed Apr 22 15:31:18 2015 +0000
+++ b/xbee900hp.cpp	Thu Apr 23 17:09:28 2015 +0000
@@ -8,8 +8,8 @@
 {
     _xbeespi.format(8,0);
     _xbeespi.frequency(1000000);
-       
-    _pin_attn.fall(this, &xbee900hp::readDataISR);
+    
+    reset();
 }
 
 /**
@@ -18,18 +18,10 @@
 xbee900hp::~xbee900hp() {}
 
 /**
-* Read Data ISR
-*/
-void xbee900hp::readDataISR() {
-    // Nothing Yet
-}
-
-/**
 * Reset xBee to SPI mode
 */
 void xbee900hp::reset()
 {
-    // Set Xbee to SPI mode
     _pin_rst = 0;
     // Minimum pulse is 1ms
     wait_ms(1);
@@ -100,6 +92,77 @@
     _xbeespi.write(checksum);
 }
 
+int xbee900hp::readPacket(char* data) {
+    unsigned int temp1;
+    unsigned int temp2;
+    
+    unsigned int checksumsub = 0;
+    unsigned int checksum;
+    
+    // get first vars.
+    temp1 = _xbeespi.write(0x00);
+    if (temp1 != 0x7E) {
+        // drop packet
+        return 1;
+    }
+    // Get length of message
+    temp1 = _xbeespi.write(0x00);
+    temp2 = _xbeespi.write(0x00);
+    
+    // Get total length
+    unsigned int length = (temp1<<8) | temp2;
+    
+    // Next read frame type to ensure it is an RX packet.
+    temp1 = _xbeespi.write(0x00);
+    if (temp1 != 0x90) {
+        // drop packet
+        return 1;
+    }
+    checksumsub += temp1;
+    
+    // in our case we dont care about source address this should be modified to extract source address if needed.
+    checksumsub += _xbeespi.write(0x00);
+    checksumsub += _xbeespi.write(0x00);
+    checksumsub += _xbeespi.write(0x00);
+    checksumsub += _xbeespi.write(0x00);
+    checksumsub += _xbeespi.write(0x00);
+    checksumsub += _xbeespi.write(0x00);
+    checksumsub += _xbeespi.write(0x00);
+    checksumsub += _xbeespi.write(0x00);
+    // reserved field, we dont care about except for checksum
+    checksumsub += _xbeespi.write(0x00);
+    checksumsub += _xbeespi.write(0x00);
+    
+    // recive options we also dont care though
+    checksumsub += _xbeespi.write(0x00);
+    
+    // Now for the sweet sweet data.
+    for (int i = 0; i<(length-12); i++) {
+        *data = _xbeespi.write(0x00);
+        checksumsub += *(data++);
+    }
+    // Null terminate char array.
+    *data = NULL;
+    
+    // Get that salty checksum
+    temp1 = _xbeespi.write(0x00);
+    
+    checksumsub = checksumsub & 0xFF;
+    checksum = 0xFF - checksumsub;
+    
+    // Check the checksum
+    if (temp1 != checksum) {
+        // Checksum failure, flag to discard packet
+        return 1;
+    }
+    
+    return 0;
+}
+
+int xbee900hp::attn() {
+    return _pin_attn;
+}
+
 void xbee900hp::writeSetting(char command[2], unsigned int value) {
     // checksum Variables
     unsigned int checksum = 0;