Exercises 00 & 01 working, Documentation still in progress, moving to my source control server.

2026-02-13 14:03:09 -08:00 · 2026-02-13 14:03:09 -08:00 · 8cf97e0e5a
commit 8cf97e0e5a
parent 84d947a3f0
15 changed files with 541 additions and 0 deletions
--- a/exercises/01_lora_ascii_pingpong/src/main.cpp
+++ b/exercises/01_lora_ascii_pingpong/src/main.cpp
@ -0,0 +1,148 @@
+// 20260212 ChatGPT
+// $Id$
+// $HeadURL$
+
+#include <Arduino.h>
+#include <SPI.h>
+#include <RadioLib.h>
+
+// --- Compile-time label ---
+#ifndef NODE_LABEL
+#define NODE_LABEL "?"
+#endif
+
+// --- Pins injected via platformio.ini build_flags ---
+#ifndef LORA_CS
+#error "LORA_CS not defined"
+#endif
+#ifndef LORA_DIO1
+#error "LORA_DIO1 not defined"
+#endif
+#ifndef LORA_RESET
+#error "LORA_RESET not defined"
+#endif
+#ifndef LORA_BUSY
+#error "LORA_BUSY not defined"
+#endif
+
+// SX1262 on T-Beam Supreme (tbeam-s3-core pinout)
+SX1262 radio = new Module(LORA_CS, LORA_DIO1, LORA_RESET, LORA_BUSY);
+
+static volatile bool g_rx_flag = false;
+
+
+static void onDio1Rise() {
+  g_rx_flag = true;
+}
+
+static void print_config() {
+  Serial.printf("Node=%s\n", NODE_LABEL);
+  Serial.printf("Pins: CS=%d DIO1=%d RST=%d BUSY=%d SCK=%d MISO=%d MOSI=%d\r\n",
+                (int)LORA_CS, (int)LORA_DIO1, (int)LORA_RESET, (int)LORA_BUSY,
+                (int)LORA_SCK, (int)LORA_MISO, (int)LORA_MOSI);
+  Serial.printf("LoRa: freq=915.0 BW=125 SF=7 CR=5 txp=14\r\n");
+}
+
+void setup() {
+  Serial.begin(115200);
+  delay(250);
+  Serial.println();
+  Serial.println("Exercise 01: LoRa ASCII ping-pong (serial only)");
+
+  // Ensure SPI pins match the variant
+  SPI.begin(LORA_SCK, LORA_MISO, LORA_MOSI, LORA_CS);
+
+  int state = radio.begin(915.0 /* MHz */, 125.0 /* kHz */, 7 /* SF */, 5 /* CR */, 0x12 /* sync */, 14 /* dBm */);
+  if (state != RADIOLIB_ERR_NONE) {
+    Serial.printf("ERROR: radio.begin failed, code=%d\r\n", state);
+    while (true) delay(1000);
+  }
+
+  // Match Meshtastic-like wiring assumptions for SX1262 modules:
+  // - DIO2 used as RF switch
+  // - TCXO at 1.8V
+  //OLD radio.setDio2AsRfSwitch(true);
+  //OLD radio.setTcxoVoltage((float)LORA_TCXO_VOLTAGE);
+  // below is replacement for above 2 lines:
+
+  //maybe_setDio2AsRfSwitch(radio, true);
+  //maybe_setTcxoVoltage(radio, (float)LORA_TCXO_VOLTAGE);
+
+  // end of replacement
+  
+  // Set up RX interrupt
+  radio.setDio1Action(onDio1Rise);
+
+  // Start receiving
+  state = radio.startReceive();
+  if (state != RADIOLIB_ERR_NONE) {
+    Serial.printf("ERROR: startReceive failed, code=%d\r\n", state);
+    while (true) delay(1000);
+  }
+
+  print_config();
+}
+
+void loop() {
+  // Periodic TX (with a label-based offset to reduce collisions)
+  static uint32_t next_tx_ms = 0;
+  static uint32_t iter = 0;
+  uint32_t now = millis();
+
+  if (next_tx_ms == 0) {
+    // Offset A and B so they don't always collide
+    uint32_t offset = (NODE_LABEL[0] == 'A') ? 500 : 1500;
+    next_tx_ms = now + offset;
+  }
+
+  if ((int32_t)(now - next_tx_ms) >= 0) {
+    next_tx_ms = now + 2000; // 2 seconds for this smoke test
+
+    // String msg = String("I am ") + NODE_LABEL + " iter=" + String(iter++);
+    String msg = String(" ") + NODE_LABEL + " sends greetings. iter=" + String(iter++);
+    Serial.printf("TX: %s\r\n", msg.c_str());
+
+    //int tx = radio.transmit(msg);
+    //if (tx != RADIOLIB_ERR_NONE) {
+    //  Serial.printf("TX ERROR code=%d\r\n", tx);
+    // }
+
+    // After transmit, resume RX
+    //radio.startReceive();
+    // DIO1 triggers on TX-done as well as RX-done.
+    // If left armed, TX completion looks like RX.
+    g_rx_flag = false;
+    radio.clearDio1Action();
+    
+    int tx = radio.transmit(msg);
+    if (tx != RADIOLIB_ERR_NONE) {
+      Serial.printf("TX ERROR code=%d\r\n", tx);
+    }
+    
+    // Re-arm RX interrupt and resume RX
+    g_rx_flag = false;
+    radio.setDio1Action(onDio1Rise);
+    radio.startReceive();
+
+  }
+
+  // RX handling
+  if (g_rx_flag) {
+    g_rx_flag = false;
+
+    String rx;
+    int state = radio.readData(rx);
+    if (state == RADIOLIB_ERR_NONE) {
+      Serial.printf("RX: %s | RSSI=%.1f SNR=%.1f\r\n",
+                    rx.c_str(), radio.getRSSI(), radio.getSNR());
+    } else {
+      Serial.printf("RX ERROR code=%d\r\n", state);
+    }
+
+    // Keep receiving
+    radio.startReceive();
+  }
+
+  delay(5);
+}
+