Experimenting with FrSky code...

src/rx.c

 #include "spi.h"
 #include "timer.h"
 #include "rx.h"
-
-#ifdef DEBUG
-#include "serial.h"
-#endif
+#include "main.h"
 
 #define CHANNELS 8
 #define PPM_MIN 1000
 uint16_t c[8];
 int rssi;
 
+// original 0x5C 0x76 0x27
+uint8_t freq2 = 0x5C, freq1 = 0x70, freq0 = 0x00;
+
 static uint16_t ppmBuffer[CHANNELS];
 
 static long map(long x, long in_min, long in_max, long out_min, long out_max);
 static void writeBindingData(void);
 
 void rxInit(void) {
-#ifdef DEBUG
-    serialWriteString(0, "RX: binding\n");
-#endif
+    GDO_dir;
+
+    debugWrite("CC2500: initializing\n");
 
     initialize(1); // binding
+
+    debugWrite("CC2500: binding\n");
+
     binding();
 
-#ifdef DEBUG
-    serialWriteString(0, "RX: receiving\n");
-#endif
+    debugWrite("CC2500: receiving\n");
 
     initialize(0); // data
-    cc2500WriteReg(CC2500_0A_CHANNR, hopData[channr]);//0A-hop
-    cc2500WriteReg(CC2500_23_FSCAL3, 0x89); //23-89
+    cc2500WriteReg(CC2500_0A_CHANNR, hopData[channr]);// 0A - hop
+    cc2500WriteReg(CC2500_23_FSCAL3, 0x89); // 23 - 89
     cc2500Strobe(CC2500_SRX);
 }
 
 static void initialize(uint8_t bind) {
     cc2500ResetChip();
     cc2500WriteReg(CC2500_02_IOCFG0,   0x01); // RX complete interrupt(GDO0)
-    cc2500WriteReg(CC2500_17_MCSM1,    0x0C);
+    cc2500WriteReg(CC2500_17_MCSM1,    0x0F);
     cc2500WriteReg(CC2500_18_MCSM0,    0x18);
     cc2500WriteReg(CC2500_06_PKTLEN,   0x19); // Leave room for appended status bytes
     cc2500WriteReg(CC2500_08_PKTCTRL0, 0x05);
     cc2500WriteReg(CC2500_3E_PATABLE,  0xFF);
     cc2500WriteReg(CC2500_0B_FSCTRL1,  0x08);
     cc2500WriteReg(CC2500_0C_FSCTRL0,  0x00);
+
+#ifdef FREQ_ORIGINAL
+    /*
+     * According to the internet, these are the default FrSky
+     * FREQ values (0x5C7627) which should equal 2.404GHz.
+     * The datasheet mentions Fcarrier = Fxosc * FREQ / 2^16
+     * Therefore, FrSky seems to be using 26MHz too...?
+     */
     cc2500WriteReg(CC2500_0D_FREQ2,    0x5C);
     cc2500WriteReg(CC2500_0E_FREQ1,    0x76);
     cc2500WriteReg(CC2500_0F_FREQ0,    0x27);
+#else
+    cc2500WriteReg(CC2500_0D_FREQ2,    0x5B); // freq2
+    cc2500WriteReg(CC2500_0E_FREQ1,    0x00); // freq1
+    cc2500WriteReg(CC2500_0F_FREQ0,    0x00); // freq0
+#endif
+
     cc2500WriteReg(CC2500_10_MDMCFG4,  0xAA);
     cc2500WriteReg(CC2500_11_MDMCFG3,  0x39);
     cc2500WriteReg(CC2500_12_MDMCFG2,  0x11);
     cc2500WriteReg(CC2500_24_FSCAL2,   0x05);
     cc2500WriteReg(CC2500_25_FSCAL1,   0x00);
     cc2500WriteReg(CC2500_26_FSCAL0,   0x11);
-    cc2500WriteReg(CC2500_29_FSTEST,   0x59);
-    cc2500WriteReg(CC2500_2C_TEST2,    0x88);
-    cc2500WriteReg(CC2500_2D_TEST1,    0x31);
-    cc2500WriteReg(CC2500_2E_TEST0,    0x0B);
-    cc2500WriteReg(CC2500_03_FIFOTHR,  0x0F);
+    //cc2500WriteReg(CC2500_29_FSTEST,   0x59);
+    //cc2500WriteReg(CC2500_2C_TEST2,    0x88);
+    //cc2500WriteReg(CC2500_2D_TEST1,    0x31);
+    //cc2500WriteReg(CC2500_2E_TEST0,    0x0B);
+    //cc2500WriteReg(CC2500_03_FIFOTHR,  0x0F); // 0x07?
 
     cc2500WriteReg(CC2500_09_ADDR, bind ? 0x03 : txid[0]);
+    //cc2500WriteReg(CC2500_09_ADDR, bind ? 0x00 : txid[0]);
+
+    debugWrite("CC2500: Entering IDLE mode...\n");
 
     cc2500Strobe(CC2500_SIDLE); // Go to idle...
 
     uint8_t part = cc2500ReadReg(CC2500_30_PARTNUM);
     uint8_t version = cc2500ReadReg(CC2500_31_VERSION);
 
-    serialWriteString(0, "CC2500 Part Number: 0x");
-    serialWriteHex(0, part);
-    serialWriteString(0, "\nCC2500 Version: 0x");
-    serialWriteHex(0, version);
-    serialWriteString(0, "\n");
+    debugWrite("CC2500: Part Number: 0x");
+    debugHex(part);
+    debugWrite("\nCC2500: Version: 0x");
+    debugHex(version);
+    debugWrite("\n");
+
+    if ((part != 0x80) || (version != 0x03)) {
+        debugWrite("INVALID CC2500 STATUS! IT MAY BE DEAD!\n");
+    }
 #endif
 
     // hack: Append status, filter by address, auto-flush on bad crc, PQT=0
     readBindingData();
     if ((txid[0] != 0xff) || (txid[1] != 0xff)) {
         // valid binding data found
-#ifdef DEBUG
-        serialWriteString(0, "RX: found data in EEPROM!\n");
-#endif
+        debugWrite("RX: found data in EEPROM!\n");
         return;
     }
 
-#ifdef DEBUG
-    serialWriteString(0, "RX: no stored data, tuning...\n");
-#endif
+    debugWrite("RX: no stored data, tuning...\n");
 
     // No valid txid, forcing bind
     tuning();
     cc2500WriteReg(CC2500_0C_FSCTRL0, frequencyOffsetHack);
     eeprom_write_byte(EEPROM_BASE_ADDRESS + 101, frequencyOffsetHack);
 
-#ifdef DEBUG
-    serialWriteString(0, "RX: tuned, binding...\n");
-#endif
+    debugWrite("RX: tuned, binding...\n");
 
     performBind();
 }
 static void tuning() {
     cc2500Strobe(CC2500_SRX); // enter in rx mode
 
-    int frequencyOffsetTimer = 0;
+    uint16_t frequencyOffsetTimer = 0;
     while (1) {
         frequencyOffsetTimer++;
         if (frequencyOffsetTimer > 3000) {
             frequencyOffsetTimer = 0;
             cc2500WriteReg(CC2500_0C_FSCTRL0, frequencyOffsetHack);
-            frequencyOffsetHack += 10;
-            if (frequencyOffsetHack > 250) {
+            if (frequencyOffsetHack <= 250) {
+                frequencyOffsetHack += 5;
+            } else {
                 frequencyOffsetHack = 0;
+
+                if (freq0 < 255) {
+                    freq0++;
+                } else {
+                    freq0 = 0;
+                    if (freq1 < 255) {
+                        freq1++;
+                    } else {
+                        freq1 = 0;
+                        if (freq2 < 255) {
+                            freq2++;
+                        } else {
+                            freq2 = 0;
+                        }
+                    }
+                }
+
+                debugWrite("0x");
+                debugHex(freq2);
+                debugHex(freq1);
+                debugHex(freq0);
+                debugWrite("\n");
+
+                cc2500WriteReg(CC2500_0D_FREQ2, freq2);
+                cc2500WriteReg(CC2500_0E_FREQ1, freq1);
+                cc2500WriteReg(CC2500_0F_FREQ0, freq0);
             }
             //cc2500Strobe(CC2500_SRX); // enter in rx mode
         }
 
         if (GDO_1) {
-            ccLen = cc2500ReadReg(CC2500_3B_RXBYTES | CC2500_READ_BURST) & 0x7F;
+            debugWrite("Tuning: data flag has been set!\n");
+
+            //ccLen = cc2500ReadReg(CC2500_3B_RXBYTES | CC2500_READ_BURST) & 0x7F;
+            ccLen = cc2500ReadReg(CC2500_3B_RXBYTES) & 0x7F;
             if (ccLen) {
+                debugWrite("Tuning: got data!\n");
                 cc2500ReadFifo(ccData, ccLen);
                 if ((ccData[ccLen - 1] & 0x80)
                         && (ccData[2] == 0x01)
                         && (ccData[5] == 0x00)) {
                     break;
                 }
+            } else {
+                debugWrite("Tuning: no data?!\n");
             }
         }
 
         wdt_reset();
+
+#ifdef DEBUG
+        uartMenu();
+#endif
     }
 }
 
 
     while (1) {
         if (GDO_1) {
-            ccLen = cc2500ReadReg(CC2500_3B_RXBYTES | CC2500_READ_BURST) & 0x7F;
+            //ccLen = cc2500ReadReg(CC2500_3B_RXBYTES | CC2500_READ_BURST) & 0x7F;
+            ccLen = cc2500ReadReg(CC2500_3B_RXBYTES) & 0x7F;
             if (ccLen) {
                 cc2500ReadFifo(ccData, ccLen);
                 if ((ccData[ccLen - 1] & 0x80)
         }
 
         wdt_reset();
-    }
 
 #ifdef DEBUG
-    serialWriteString(0, "RX: got hop data, reading list...\n");
+        uartMenu();
 #endif
+    }
+
+    debugWrite("RX: got hop data, reading list...\n");
 
     listLength = 0;
     uint8_t eol = 0;
     for (uint8_t bindIdx = 0x05; bindIdx <= 120; bindIdx += 5) {
         while (1) {
             if (GDO_1) {
-                ccLen = cc2500ReadReg(CC2500_3B_RXBYTES | CC2500_READ_BURST) & 0x7F;
+                //ccLen = cc2500ReadReg(CC2500_3B_RXBYTES | CC2500_READ_BURST) & 0x7F;
+                ccLen = cc2500ReadReg(CC2500_3B_RXBYTES) & 0x7F;
                 if (ccLen) {
                     cc2500ReadFifo(ccData, ccLen);
                     if ((ccData[ccLen - 1] & 0x80)
             }
 
             wdt_reset();
+
+#ifdef DEBUG
+            uartMenu();
+#endif
         }
 
         if (eol) {
         }
     }
 
-#ifdef DEBUG
-    serialWriteString(0, "RX: binding finished!\n");
-#endif
+    debugWrite("RX: binding finished!\n");
 
     writeBindingData();
     cc2500Strobe(CC2500_SIDLE); // Back to idle
                 nextChannel(SEEK_CHANNEL_SKIP);
                 counter++;
 
-#ifdef DEBUG
                 if (counter > (MAX_MISSING_PACKET << 1)) {
-                    serialWriteString(0, "RX: missing packet notification!\n");
+                    debugWrite("RX: missing packet notification!\n");
                 }
-#endif
 
                 if (counter == (MAX_MISSING_PACKET << 2)) counter = 0;
                 break;
         }
 
         if (GDO_1) {
-            ccLen = cc2500ReadReg(CC2500_3B_RXBYTES | CC2500_READ_BURST) & 0x7F;
+            //ccLen = cc2500ReadReg(CC2500_3B_RXBYTES | CC2500_READ_BURST) & 0x7F;
+            ccLen = cc2500ReadReg(CC2500_3B_RXBYTES) & 0x7F;
             if (ccLen > 20) {
                 ccLen = 20;
             }
                         packet = 1;
 
 #ifdef RSSI_OVER_PPM
-                        int rssi_dec = cc2500ReadReg(CC2500_34_RSSI | CC2500_READ_BURST);
+                        //int rssi_dec = cc2500ReadReg(CC2500_34_RSSI | CC2500_READ_BURST);
+                        int rssi_dec = cc2500ReadReg(CC2500_34_RSSI);
                         if (rssi_dec < 128) {
                             rssi = ((rssi_dec / 2) - RSSI_OFFSET) & 0x7f;
                         } else {
         }
 
         wdt_reset();
+
+#ifdef DEBUG
+        uartMenu();
+#endif
     }
 
     if (packet != 0) {
         ppmBuffer[RSSI_OVER_PPM] = map(rssi, RSSI_MIN, RSSI_MAX, PPM_MIN, PPM_MAX);
 #endif
 
-#ifdef DEBUG
-        serialWriteString(0, "RX: packet received, sending CPPM!\n");
-#endif
-
+        debugWrite("RX: packet received, sending CPPM!\n");
         cppmCopy(ppmBuffer);
     }