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IoT
PaperMono LoRa Arduino 使用教程
PaperMono LoRa 案例程序。
案例程序
编译要求
- M5Stack 板管理版本 >= 3.3.9
- 开发板选项 =
M5PaperMono - M5Unified 库版本 >= 0.2.20
- M5GFX 库版本 >= 0.2.27
- RadioLib 库版本 >= 7.2.1
- M5PM1 库版本 >= 1.0.7
- M5IOE1 库版本 >= 1.0.9
注意
PaperMono 板载 SX1262 使用
SCK=39、MISO=40、MOSI=38、NSS=41 的独立 SPI 引脚。代码必须在创建 RadioLib Module 时传入 loraSpi 和对应的 SPISettings，并在调用 radio.begin() 前执行 loraSpi.begin(kSckPin, kMisoPin, kMosiPin, kNssPin)。省略这些设置可能使 RadioLib 使用默认 SPI 引脚，导致无法与 SX1262 通信并出现初始化失败，常见错误码为 RADIOLIB_ERR_CHIP_NOT_FOUND (-2)。PaperMono 的 LoRa 供电使能信号 LoRa_EN 连接至 M5PM1 GPIO2；SX1262 复位信号 SX_NRST 和天线开关信号 SX_ANT_SW 分别连接至 M5IOE1 GPIO10 (M5IOE1_PIN_10) 和 GPIO2 (M5IOE1_PIN_2)。下方案例程序会先拉高 M5PM1 GPIO2 打开 LoRa 供电，再通过 M5IOE1 GPIO10 复位 SX1262，并根据收发状态控制 M5IOE1 GPIO2 开关天线通道；如果未正确配置这些引脚，SX1262 可能无法正常初始化或收发。
发送端
程序通过控制 M5PM1 打开 LoRa 供电、天线开关并完成 SX1262 复位。SX1262 初始化后，每隔 3 秒发送一条带递增编号的 Hello PaperMono #X 消息，并在屏幕和串口监视器中显示发送结果。
cpp
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#include <Arduino.h>
#include <M5IOE1.h>
#include <M5PM1.h>
#include <M5Unified.h>
#include <RadioLib.h>
#include <SPI.h>
namespace {
constexpr float kFrequencyMhz = 868.0f;
constexpr float kBandwidthKhz = 125.0f;
constexpr uint8_t kSpreadingFactor = 12;
constexpr uint8_t kCodingRate = 5;
constexpr uint8_t kSyncWord = 0x34;
constexpr int8_t kTxPowerDbm = 22;
constexpr uint16_t kPreambleLength = 20;
constexpr uint32_t kSendIntervalMs = 3000;
constexpr int kMosiPin = 38;
constexpr int kMisoPin = 40;
constexpr int kSckPin = 39;
constexpr int kNssPin = 41;
constexpr int kIrqPin = 5;
constexpr int kBusyPin = 21;
constexpr uint32_t kSpiFrequencyHz = 8000000;
constexpr auto kResetPin = M5IOE1_PIN_10;
constexpr auto kAntennaSwitchPin = M5IOE1_PIN_2;
SPIClass loraSpi(HSPI);
SX1262 radio = new Module(
kNssPin, kIrqPin, RADIOLIB_NC, kBusyPin, loraSpi,
SPISettings(kSpiFrequencyHz, MSBFIRST, SPI_MODE0));
M5Canvas canvas(&M5.Display);
M5PM1 pm1;
M5IOE1 ioe1;
volatile bool transmissionFinished = false;
int transmissionState = RADIOLIB_ERR_NONE;
uint32_t messageNumber = 1;
void IRAM_ATTR onTransmissionFinished()
{
transmissionFinished = true;
}
void drawScreen(const String& state, const String& message,
const String& detail = "")
{
canvas.fillSprite(TFT_WHITE);
canvas.setTextDatum(middle_center);
canvas.setTextColor(TFT_BLACK, TFT_WHITE);
canvas.setFont(&fonts::FreeSansBold24pt7b);
canvas.drawString("LoRa TX", 240, 95);
canvas.drawFastHLine(40, 150, 400, TFT_BLACK);
canvas.setFont(&fonts::FreeSansBold18pt7b);
canvas.drawString(state, 240, 220);
canvas.setFont(&fonts::FreeSansBold12pt7b);
canvas.drawString(message, 240, 330);
canvas.setFont(&fonts::FreeSans12pt7b);
canvas.drawString(detail, 240, 405);
canvas.drawString("868.0 MHz | SF12 | 16 dBm", 240, 665);
canvas.pushSprite(0, 0);
}
[[noreturn]] void stopWithError(const String& message, int code)
{
Serial.printf("%s, code: %d\n", message.c_str(), code);
drawScreen("ERROR", message, "Code: " + String(code));
while (true) {
delay(1000);
}
}
bool enableLoRaHardware()
{
const m5pm1_err_t pm1Error =
pm1.begin(&M5.In_I2C, M5PM1_DEFAULT_ADDR, M5PM1_I2C_FREQ_100K);
if (pm1Error != M5PM1_OK) {
Serial.printf("M5PM1 init failed, code: %d\n", pm1Error);
return false;
}
if (pm1.gpioSetFunc(M5PM1_GPIO_NUM_2, M5PM1_GPIO_FUNC_GPIO) != M5PM1_OK ||
pm1.gpioSet(M5PM1_GPIO_NUM_2, M5PM1_GPIO_MODE_OUTPUT, HIGH,
M5PM1_GPIO_PULL_NONE,
M5PM1_GPIO_DRIVE_PUSHPULL) != M5PM1_OK) {
Serial.println("LoRa power enable failed");
return false;
}
Serial.println("LoRa power: enabled");
const m5ioe1_err_t ioeError = ioe1.begin(
&M5.In_I2C, M5IOE1_DEFAULT_ADDR_2, M5IOE1_I2C_FREQ_100K);
if (ioeError != M5IOE1_OK) {
Serial.printf("M5IOE1 init failed, code: %d\n", ioeError);
return false;
}
ioe1.pinMode(kResetPin, OUTPUT);
ioe1.pinMode(kAntennaSwitchPin, OUTPUT);
if (ioe1.setDriveMode(kResetPin, M5IOE1_DRIVE_PUSHPULL) != M5IOE1_OK ||
ioe1.setDriveMode(kAntennaSwitchPin, M5IOE1_DRIVE_PUSHPULL) != M5IOE1_OK) {
Serial.println("LoRa IO drive setup failed");
return false;
}
delay(200);
m5ioe1_err_t ioeWriteError = M5IOE1_OK;
ioe1.digitalWriteWithRes(kResetPin, LOW, &ioeWriteError);
delay(100);
ioe1.digitalWriteWithRes(kResetPin, HIGH, &ioeWriteError);
delay(200);
if (ioeWriteError != M5IOE1_OK) {
Serial.printf("LoRa reset failed, code: %d\n", ioeWriteError);
return false;
}
pinMode(kBusyPin, INPUT);
Serial.printf("LoRa reset: released, BUSY=%d\n", digitalRead(kBusyPin));
return true;
}
void startPacket()
{
String message = "Hello PaperMono #" + String(messageNumber);
Serial.printf("[LoRa TX] Sending: %s\n", message.c_str());
ioe1.digitalWrite(kAntennaSwitchPin, HIGH);
transmissionState = radio.startTransmit(message);
if (transmissionState != RADIOLIB_ERR_NONE) {
transmissionFinished = true;
}
}
} // namespace
void setup()
{
Serial.begin(115200);
delay(100);
Serial.println("PaperMONO LoRa sender");
auto config = M5.config();
config.clear_display = false;
config.internal_rtc = false;
config.internal_imu = false;
config.internal_mic = false;
M5.begin(config);
M5.Display.setRotation(0);
M5.Display.setBrightness(160);
M5.Display.setEpdMode(epd_mode_t::epd_fast);
canvas.setColorDepth(16);
if (!canvas.createSprite(M5.Display.width(), M5.Display.height())) {
Serial.println("Display canvas allocation failed");
while (true) delay(1000);
}
drawScreen("INITIALIZING", "SX1262");
if (!enableLoRaHardware()) {
stopWithError("LoRa power init failed", -1);
}
loraSpi.begin(kSckPin, kMisoPin, kMosiPin, kNssPin);
Serial.println("LoRa SPI: HSPI/SPI3 at 8 MHz");
const int state = radio.begin(kFrequencyMhz, kBandwidthKhz,
kSpreadingFactor, kCodingRate, kSyncWord,
kTxPowerDbm, kPreambleLength, 3.0f, true);
if (state != RADIOLIB_ERR_NONE) {
stopWithError("SX1262 init failed", state);
}
radio.setCurrentLimit(140);
radio.setPacketSentAction(onTransmissionFinished);
drawScreen("READY", "Sending every 3 seconds");
startPacket();
}
void loop()
{
if (!transmissionFinished) {
delay(5);
return;
}
transmissionFinished = false;
const String message = "Hello PaperMono #" + String(messageNumber);
if (transmissionState == RADIOLIB_ERR_NONE) {
Serial.printf("[LoRa TX] Sent: %s\n", message.c_str());
drawScreen("SENT", message,
"Message " + String(messageNumber));
} else {
Serial.printf("[LoRa TX] Failed, code: %d\n", transmissionState);
drawScreen("SEND FAILED", message,
"Code: " + String(transmissionState));
}
radio.finishTransmit();
delay(kSendIntervalMs);
++messageNumber;
startPacket();
}接收端
将下方程序烧录到另一台 PaperMono，接收参数需与发送端保持一致。
cpp
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#include <Arduino.h>
#include <M5IOE1.h>
#include <M5PM1.h>
#include <M5Unified.h>
#include <RadioLib.h>
#include <SPI.h>
namespace {
constexpr float kFrequencyMhz = 868.0f;
constexpr float kBandwidthKhz = 125.0f;
constexpr uint8_t kSpreadingFactor = 12;
constexpr uint8_t kCodingRate = 5;
constexpr uint8_t kSyncWord = 0x34;
constexpr int8_t kTxPowerDbm = 22;
constexpr uint16_t kPreambleLength = 20;
constexpr int kMosiPin = 38;
constexpr int kMisoPin = 40;
constexpr int kSckPin = 39;
constexpr int kNssPin = 41;
constexpr int kIrqPin = 5;
constexpr int kBusyPin = 21;
constexpr uint32_t kSpiFrequencyHz = 8000000;
constexpr auto kResetPin = M5IOE1_PIN_10;
constexpr auto kAntennaSwitchPin = M5IOE1_PIN_2;
SPIClass loraSpi(HSPI);
SX1262 radio = new Module(
kNssPin, kIrqPin, RADIOLIB_NC, kBusyPin, loraSpi,
SPISettings(kSpiFrequencyHz, MSBFIRST, SPI_MODE0));
M5Canvas canvas(&M5.Display);
M5PM1 pm1;
M5IOE1 ioe1;
volatile bool packetReceived = false;
uint32_t receivedCount = 0;
void IRAM_ATTR onPacketReceived()
{
packetReceived = true;
}
void drawScreen(const String& state, const String& message,
const String& rssi = "", const String& snr = "",
const String& detail = "")
{
canvas.fillSprite(TFT_WHITE);
canvas.setTextDatum(middle_center);
canvas.setTextColor(TFT_BLACK, TFT_WHITE);
canvas.setFont(&fonts::FreeSansBold24pt7b);
canvas.drawString("LoRa RX", 240, 95);
canvas.drawFastHLine(40, 150, 400, TFT_BLACK);
canvas.setFont(&fonts::FreeSansBold18pt7b);
canvas.drawString(state, 240, 215);
canvas.setFont(&fonts::FreeSansBold12pt7b);
canvas.drawString(message, 240, 310);
canvas.setFont(&fonts::FreeSans12pt7b);
canvas.drawString(rssi, 240, 390);
canvas.drawString(snr, 240, 445);
canvas.drawString(detail, 240, 515);
canvas.drawString("868.0 MHz | SF12 | CR 4/5", 240, 665);
canvas.pushSprite(0, 0);
}
[[noreturn]] void stopWithError(const String& message, int code)
{
Serial.printf("%s, code: %d\n", message.c_str(), code);
drawScreen("ERROR", message, "Code: " + String(code));
while (true) {
delay(1000);
}
}
bool enableLoRaHardware()
{
const m5pm1_err_t pm1Error =
pm1.begin(&M5.In_I2C, M5PM1_DEFAULT_ADDR, M5PM1_I2C_FREQ_100K);
if (pm1Error != M5PM1_OK) {
Serial.printf("M5PM1 init failed, code: %d\n", pm1Error);
return false;
}
if (pm1.gpioSetFunc(M5PM1_GPIO_NUM_2, M5PM1_GPIO_FUNC_GPIO) != M5PM1_OK ||
pm1.gpioSet(M5PM1_GPIO_NUM_2, M5PM1_GPIO_MODE_OUTPUT, HIGH,
M5PM1_GPIO_PULL_NONE,
M5PM1_GPIO_DRIVE_PUSHPULL) != M5PM1_OK) {
Serial.println("LoRa power enable failed");
return false;
}
Serial.println("LoRa power: enabled");
const m5ioe1_err_t ioeError = ioe1.begin(
&M5.In_I2C, M5IOE1_DEFAULT_ADDR_2, M5IOE1_I2C_FREQ_100K);
if (ioeError != M5IOE1_OK) {
Serial.printf("M5IOE1 init failed, code: %d\n", ioeError);
return false;
}
ioe1.pinMode(kResetPin, OUTPUT);
ioe1.pinMode(kAntennaSwitchPin, OUTPUT);
if (ioe1.setDriveMode(kResetPin, M5IOE1_DRIVE_PUSHPULL) != M5IOE1_OK ||
ioe1.setDriveMode(kAntennaSwitchPin, M5IOE1_DRIVE_PUSHPULL) != M5IOE1_OK) {
Serial.println("LoRa IO drive setup failed");
return false;
}
ioe1.digitalWrite(kAntennaSwitchPin, LOW);
delay(200);
m5ioe1_err_t ioeWriteError = M5IOE1_OK;
ioe1.digitalWriteWithRes(kResetPin, LOW, &ioeWriteError);
delay(100);
ioe1.digitalWriteWithRes(kResetPin, HIGH, &ioeWriteError);
delay(200);
if (ioeWriteError != M5IOE1_OK) {
Serial.printf("LoRa reset failed, code: %d\n", ioeWriteError);
return false;
}
pinMode(kBusyPin, INPUT);
Serial.printf("LoRa reset: released, BUSY=%d\n", digitalRead(kBusyPin));
return true;
}
void resumeReceive()
{
ioe1.digitalWrite(kAntennaSwitchPin, LOW);
const int state = radio.startReceive();
if (state != RADIOLIB_ERR_NONE) {
stopWithError("Listen failed", state);
}
}
} // namespace
void setup()
{
Serial.begin(115200);
delay(100);
Serial.println("PaperMONO LoRa receiver");
auto config = M5.config();
config.clear_display = false;
config.internal_rtc = false;
config.internal_imu = false;
config.internal_mic = false;
M5.begin(config);
M5.Display.setRotation(0);
M5.Display.setBrightness(160);
M5.Display.setEpdMode(epd_mode_t::epd_fast);
canvas.setColorDepth(16);
if (!canvas.createSprite(M5.Display.width(), M5.Display.height())) {
Serial.println("Display canvas allocation failed");
while (true) delay(1000);
}
drawScreen("INITIALIZING", "SX1262");
if (!enableLoRaHardware()) {
stopWithError("LoRa power init failed", -1);
}
loraSpi.begin(kSckPin, kMisoPin, kMosiPin, kNssPin);
Serial.println("LoRa SPI: HSPI/SPI3 at 8 MHz");
const int state = radio.begin(kFrequencyMhz, kBandwidthKhz,
kSpreadingFactor, kCodingRate, kSyncWord,
kTxPowerDbm, kPreambleLength, 3.0f, true);
if (state != RADIOLIB_ERR_NONE) {
stopWithError("SX1262 init failed", state);
}
radio.setCurrentLimit(140);
radio.setPacketReceivedAction(onPacketReceived);
resumeReceive();
Serial.println("[LoRa RX] Listening...");
drawScreen("LISTENING", "Waiting for a packet");
}
void loop()
{
if (!packetReceived) {
delay(5);
return;
}
packetReceived = false;
String message;
const int state = radio.readData(message);
if (state == RADIOLIB_ERR_NONE) {
++receivedCount;
const float rssi = radio.getRSSI();
const float snr = radio.getSNR();
const float frequencyError = radio.getFrequencyError();
Serial.printf("[LoRa RX] Data: %s\n", message.c_str());
Serial.printf("[LoRa RX] RSSI: %.2f dBm, SNR: %.2f dB\n", rssi, snr);
Serial.printf("[LoRa RX] Frequency error: %.2f Hz\n", frequencyError);
drawScreen("RECEIVED", message,
"RSSI " + String(rssi, 2) + " dBm",
"SNR " + String(snr, 2) + " dB",
"Packets " + String(receivedCount));
} else if (state == RADIOLIB_ERR_CRC_MISMATCH) {
Serial.println("[LoRa RX] CRC mismatch");
drawScreen("CRC ERROR", "Packet discarded");
} else {
Serial.printf("[LoRa RX] Read failed, code: %d\n", state);
drawScreen("READ FAILED", "Code: " + String(state));
}
resumeReceive();
}接收端会持续监听 LoRa 数据。收到数据后，屏幕会显示消息内容、累计接收数量、RSSI 和 SNR，串口监视器还会输出频率误差；出现 CRC 校验错误或读取失败时会显示对应状态，随后自动恢复接收。
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