From 4bc7668ae98ff8041a7fa7b49325915f4f4cf865 Mon Sep 17 00:00:00 2001
From: "Pawel Spychalski (DzikuVx)" <pspychalski@gmail.com>
Date: Sat, 30 Sep 2017 18:43:03 +0200
Subject: [PATCH] Support for SPI connected SX1278

---
 .vscode/arduino.json |  3 +-
 README.md            |  2 +-
 build/.gitkeep       |  0
 crossbow.ino         | 82 +++++++++++++++++++++++++++++++++++++++++++++++-----
 4 files changed, 77 insertions(+), 10 deletions(-)
 delete mode 100644 build/.gitkeep

diff --git a/.vscode/arduino.json b/.vscode/arduino.json
index 265a87f..56ce281 100644
--- a/.vscode/arduino.json
+++ b/.vscode/arduino.json
@@ -1,6 +1,5 @@
 {
-    "board": "arduino:avr:pro",
-    "configuration": "cpu=16MHzatmega328",
+    "board": "bsfrance:avr:lora32u4",
     "sketch": "crossbow.ino",
     "port": "COM23",
     "output": "./build"
diff --git a/README.md b/README.md
index 1bb774b..ca64cc7 100644
--- a/README.md
+++ b/README.md
@@ -1,6 +1,6 @@
 # QuadMeUp Crossbow
 
-_QuadMeUp Crossbow_ is a DIY project that gives 5km (at least) of RC link for UAV (airplanes and drones) for a price below $40. I uses SX1276 (LoRa 868MHz/915MHz) compatible (like HopeRF RFM95W) radio modules connected to Arduino compatible boards. It can be regular Arduino connected via SPI to SX1276 or dedicated board like _Adafruit Feather 32u4 RFM LoRa_ or _LoRa32u4 II_
+_QuadMeUp Crossbow_ is a DIY project that gives 5km (at least) of RC link for UAV (airplanes and drones) for a price below $40. I uses SX1278 (LoRa 868MHz/915MHz) compatible (like HopeRF RFM95W) radio modules connected to Arduino compatible boards. It can be regular Arduino connected via SPI to SX1278 or dedicated board like _Adafruit Feather 32u4 RFM LoRa_ or _LoRa32u4 II_
 
 # Current state
 
diff --git a/build/.gitkeep b/build/.gitkeep
deleted file mode 100644
index e69de29..0000000
diff --git a/crossbow.ino b/crossbow.ino
index f5e7b44..e0c604b 100644
--- a/crossbow.ino
+++ b/crossbow.ino
@@ -1,7 +1,11 @@
+#include <LoRa.h>
 #include "variables.h"
 
-// #define DEVICE_MODE_TX
-#define DEVICE_MODE_RX
+// #define LORA_HARDWARE_SERIAL
+#define LORA_HARDWARE_SPI
+
+#define DEVICE_MODE_TX
+// #define DEVICE_MODE_RX
 
 /*
  * Main defines for device working in TX mode
@@ -199,14 +203,55 @@ uint8_t get10bitLowShift(uint8_t channel) {
     return 8 - get10bitHighShift(channel);
 }
 
+void computeCrc(uint8_t dataByte) {
+    qspCrc ^= dataByte;
+}
+
+/*
+ * Serial port used to send data
+ */
+#ifdef LORA_HARDWARE_SERIAL
+
+void radioPacketStart(void) {
+
+}
+
+void radioPacketEnd(void) {
+    Serial.end();
+    delay(E45_TTL_100_UART_DOWNTIME);
+    Serial.begin(UART_SPEED);
+}
+
 void writeToRadio(uint8_t dataByte) {
     //Compute CRC
-    qspCrc ^= dataByte;
+    computeCrc(dataByte);
 
     //Write to radio
     Serial.write(dataByte);
 }
 
+#endif
+
+#ifdef LORA_HARDWARE_SPI
+
+void radioPacketStart(void) {
+    LoRa.beginPacket();
+}
+
+void radioPacketEnd(void) {
+    LoRa.endPacket();
+}
+
+void writeToRadio(uint8_t dataByte) {
+    //Compute CRC
+    computeCrc(dataByte);
+
+    //Write to radio
+    LoRa.write(dataByte);
+}
+
+#endif
+
 /*
 display.clearDisplay();
 display.setCursor(0,0);
@@ -216,7 +261,19 @@ display.display();
 */
 
 void setup(void) {
+
+#ifdef LORA_HARDWARE_SERIAL
     Serial.begin(UART_SPEED);
+#endif
+
+#ifdef LORA_HARDWARE_SPI
+    if (!LoRa.begin(868E6)) {
+        Serial.println("LoRa init failed. Check your connections.");
+        while (true);
+    }
+    LoRa.onReceive(onReceive);
+    LoRa.receive();
+#endif
 
 #ifdef DEVICE_MODE_RX
     pinMode(PIN_LED, OUTPUT);
@@ -299,17 +356,28 @@ void loop(void) {
 
 #endif
 
+#ifdef LORA_HARDWARE_SERIAL 
     if (Serial.available()) {
         qspDecodeIncomingFrame(Serial.read());
     }
+#endif
 
     if (transmitPayload) {
         transmitPayload = false;
 
+        radioPacketStart();
         qspEncodeFrame(qspFrameToSend, qspPayloadLength, qspPayload);
-        Serial.end();
-        delay(E45_TTL_100_UART_DOWNTIME);
-        Serial.begin(UART_SPEED);
+        radioPacketEnd();
     }
 
-}
\ No newline at end of file
+}
+
+#ifdef LORA_HARDWARE_SPI
+void onReceive(int packetSize) {
+    if (packetSize == 0) return;
+
+    while (LoRa.available()) {
+        qspDecodeIncomingFrame(LoRa.read());
+    }
+}
+#endif
\ No newline at end of file