Files
halehound/include/radio_nrf24.h
2026-10-06 23:43:26 -07:00

249 lines
7.0 KiB
C++

#ifndef RADIO_NRF24_H
#define RADIO_NRF24_H
#include <SPI.h>
#include "board_config.h"
// NRF24L01+ 2.4GHz Radio Driver
// PA+LNA module for range, all TX at +20dBm
class RadioNRF24 {
public:
// Initialize NRF24
static bool begin() {
pinMode(NRF24_CSN, OUTPUT);
pinMode(NRF24_CE, OUTPUT);
pinMode(NRF24_IRQ, INPUT);
digitalWrite(NRF24_CSN, HIGH);
digitalWrite(NRF24_CE, LOW);
// Start SPI
SPI.begin(RADIO_SPI_CLK, RADIO_SPI_MISO, RADIO_SPI_MOSI);
SPI.setFrequency(10000000);
SPI.setDataMode(SPI_MODE0);
delay(100);
// Verify chip
uint8_t id = readReg(0x00); // CONFIG
if ((id & 0x0F) == 0x00) {
return false; // Not responding
}
// Reset config
writeReg(0x00, 0x08); // PWR_UP, CRC enabled
delay(150);
// Setup for max power 2.4GHz
writeReg(0x01, 0x03); // EN_AA = 0x03 (pipe 0,1)
writeReg(0x02, 0x03); // EN_RXADDR = 0x03 (pipe 0,1)
writeReg(0x03, 0x03); // SETUP_AW = 5 bytes
writeReg(0x04, 0x2F); // SETUP_RETR = ARD=750us, ARC=15
writeReg(0x05, 0x76); // RF_CH = 118 (2476 MHz center)
writeReg(0x06, 0x0F); // RF_SETUP = PA_MAX, 2Mbps, LNA on
// Set RX addresses
setRxAddress(0, 0x6E6B6C6D6ELL);
setRxAddress(1, 0x6B6C6D6E6FLL);
// Set TX address
setTxAddress(0x6E6B6C6D6ELL);
// Enable RX
writeReg(0x00, 0x0B); // PWR_UP + PRIM_RX
digitalWrite(NRF24_CE, HIGH);
return true;
}
// Set RX channel (0-125, maps to 2400-3525 MHz)
static void setChannel(uint8_t ch) {
if (ch > 125) ch = 125;
writeReg(0x05, ch);
}
// Set TX power: 0x0F=+20dBm, 0x07=0dBm, 0x03=-6dBm, 0x00=-18dBm
static void setTxPower(uint8_t pwr) {
uint8_t rf_setup = readReg(0x06);
rf_setup = (rf_setup & 0xF9) | ((pwr & 0x03) << 1);
writeReg(0x06, rf_setup);
}
// Set max TX power
static void setMaxPower() {
setTxPower(0x03); // PA_MAX on NRF24L01+PA+LNA
}
// Set data rate: 0x00=1Mbps, 0x08=2Mbps, 0x20=250kbps
static void setDataRate(uint8_t rate) {
uint8_t rf_setup = readReg(0x06);
rf_setup = (rf_setup & 0xD7) | (rate & 0x28);
writeReg(0x06, rf_setup);
}
// Transmit packet
static bool transmit(const uint8_t* data, uint8_t len) {
if (len > 32) return false;
// Go to TX mode
uint8_t config = readReg(0x00);
writeReg(0x00, config & 0xFE); // Clear PRIM_RX
digitalWrite(NRF24_CE, LOW);
// Load TX FIFO
digitalWrite(NRF24_CSN, LOW);
SPI.transfer(0xA0); // W_TX_PAYLOAD
for (uint8_t i = 0; i < len; i++) {
SPI.transfer(data[i]);
}
digitalWrite(NRF24_CSN, HIGH);
// Start transmission
digitalWrite(NRF24_CE, HIGH);
delayMicroseconds(15);
digitalWrite(NRF24_CE, LOW);
// Wait for completion or timeout
uint32_t start = millis();
while (millis() - start < 5000) {
uint8_t status = getStatus();
if (status & 0x20) { // TX_DS = transmission complete
// Clear interrupt
writeReg(0x07, 0x20);
return true;
}
if (status & 0x10) { // MAX_RT = max retries reached
// Clear interrupt
writeReg(0x07, 0x10);
return false;
}
delay(1);
}
return false;
}
// Receive packet (non-blocking)
// Returns length of packet or 0 if none
static uint8_t receive(uint8_t* buffer, uint8_t max_len) {
uint8_t status = getStatus();
if (!(status & 0x40)) { // RX_DR = data ready
return 0;
}
// Read payload
uint8_t len = readReg(0x60); // RX_PL_WID
if (len > max_len) len = max_len;
digitalWrite(NRF24_CSN, LOW);
SPI.transfer(0x61); // R_RX_PAYLOAD
for (uint8_t i = 0; i < len; i++) {
buffer[i] = SPI.transfer(0x00);
}
digitalWrite(NRF24_CSN, HIGH);
// Clear RX FIFO
writeReg(0x07, 0x40); // Clear RX_DR flag
return len;
}
// Get signal strength (RSSI estimation)
// No built-in RSSI on NRF24, so estimate from carrier detect
static int8_t getRSSI() {
uint8_t cd = readReg(0x09); // CD (carrier detect)
if (cd & 0x01) {
return -50; // Signal present
}
return -90; // No signal
}
// Enter listening (RX) mode
static void listenMode() {
digitalWrite(NRF24_CE, LOW);
uint8_t config = readReg(0x00);
writeReg(0x00, config | 0x01); // PRIM_RX
digitalWrite(NRF24_CE, HIGH);
}
// Sleep mode (low power)
static void sleep() {
digitalWrite(NRF24_CE, LOW);
uint8_t config = readReg(0x00);
writeReg(0x00, config & 0xFD); // PWR_UP = 0
}
static void wakeup() {
uint8_t config = readReg(0x00);
writeReg(0x00, config | 0x02); // PWR_UP
delay(5);
digitalWrite(NRF24_CE, HIGH);
}
// Promiscuous mode (Goodspeed) - capture all 2.4GHz packets
static void enablePromiscuous() {
// Disable address matching
writeReg(0x02, 0x01); // EN_RXADDR = pipe 0 only
writeReg(0x03, 0x03); // SETUP_AW = 5 bytes
// Set minimal RX address (all zeros)
uint8_t addr[5] = {0x00, 0x00, 0x00, 0x00, 0x00};
setRxAddress(0, 0x0000000000LL);
listenMode();
}
// Spectrum scanner - sweep channels and measure signal
static uint8_t scanChannel(uint8_t channel) {
setChannel(channel);
delay(40);
return readReg(0x09) & 0x01; // CD bit = carrier detect
}
private:
static uint8_t getStatus() {
digitalWrite(NRF24_CSN, LOW);
uint8_t status = SPI.transfer(0xFF);
digitalWrite(NRF24_CSN, HIGH);
return status;
}
static uint8_t readReg(uint8_t reg) {
digitalWrite(NRF24_CSN, LOW);
SPI.transfer(reg & 0x1F); // Max 5 bits
uint8_t val = SPI.transfer(0x00);
digitalWrite(NRF24_CSN, HIGH);
return val;
}
static void writeReg(uint8_t reg, uint8_t val) {
digitalWrite(NRF24_CSN, LOW);
SPI.transfer((reg & 0x1F) | 0x20); // Write flag
SPI.transfer(val);
digitalWrite(NRF24_CSN, HIGH);
}
static void setRxAddress(uint8_t pipe, uint64_t addr) {
uint8_t reg = 0x0A + pipe; // RX_ADDR_P0-P5
digitalWrite(NRF24_CSN, LOW);
SPI.transfer(reg | 0x20);
for (int i = 0; i < 5; i++) {
SPI.transfer((addr >> (i * 8)) & 0xFF);
}
digitalWrite(NRF24_CSN, HIGH);
}
static void setTxAddress(uint64_t addr) {
uint8_t reg = 0x10; // TX_ADDR
digitalWrite(NRF24_CSN, LOW);
SPI.transfer(reg | 0x20);
for (int i = 0; i < 5; i++) {
SPI.transfer((addr >> (i * 8)) & 0xFF);
}
digitalWrite(NRF24_CSN, HIGH);
}
};
#endif // RADIO_NRF24_H