opencom_xl_firmware/RNode_Firmware.ino

924 lines
23 KiB
C++

// MIT License
//
// Copyright (c) 2022 Mark Qvist - unsigned.io/rnode
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in all
// copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
// SOFTWARE.
#include <Arduino.h>
#include <SPI.h>
#include "Utilities.h"
FIFOBuffer serialFIFO;
uint8_t serialBuffer[CONFIG_UART_BUFFER_SIZE+1];
FIFOBuffer16 packet_starts;
uint16_t packet_starts_buf[CONFIG_QUEUE_MAX_LENGTH+1];
FIFOBuffer16 packet_lengths;
uint16_t packet_lengths_buf[CONFIG_QUEUE_MAX_LENGTH+1];
uint8_t packet_queue[CONFIG_QUEUE_SIZE];
volatile uint8_t queue_height = 0;
volatile uint16_t queued_bytes = 0;
volatile uint16_t queue_cursor = 0;
volatile uint16_t current_packet_start = 0;
volatile bool serial_buffering = false;
char sbuf[128];
#if MCU_VARIANT == MCU_ESP32
bool packet_ready = false;
#endif
void setup() {
#if MCU_VARIANT == MCU_ESP32
delay(500);
EEPROM.begin(EEPROM_SIZE);
Serial.setRxBufferSize(CONFIG_UART_BUFFER_SIZE);
#endif
// Seed the PRNG
randomSeed(analogRead(0));
// Initialise serial communication
memset(serialBuffer, 0, sizeof(serialBuffer));
fifo_init(&serialFIFO, serialBuffer, CONFIG_UART_BUFFER_SIZE);
Serial.begin(serial_baudrate);
while (!Serial);
serial_interrupt_init();
// Configure input and output pins
pinMode(pin_led_rx, OUTPUT);
pinMode(pin_led_tx, OUTPUT);
// Initialise buffers
memset(pbuf, 0, sizeof(pbuf));
memset(cbuf, 0, sizeof(cbuf));
memset(packet_queue, 0, sizeof(packet_queue));
memset(packet_starts_buf, 0, sizeof(packet_starts_buf));
fifo16_init(&packet_starts, packet_starts_buf, CONFIG_QUEUE_MAX_LENGTH);
memset(packet_lengths_buf, 0, sizeof(packet_starts_buf));
fifo16_init(&packet_lengths, packet_lengths_buf, CONFIG_QUEUE_MAX_LENGTH);
// Set chip select, reset and interrupt
// pins for the LoRa module
LoRa.setPins(pin_cs, pin_reset, pin_dio);
#if MCU_VARIANT == MCU_ESP32
#if HAS_PMU == true
pmu_ready = init_pmu();
#endif
kiss_indicate_reset();
#endif
// Validate board health, EEPROM and config
validateStatus();
#if HAS_DISPLAY
disp_ready = display_init();
#endif
#if HAS_BLUETOOTH
bt_ready = bt_init();
#endif
}
void lora_receive() {
if (!implicit) {
LoRa.receive();
} else {
LoRa.receive(implicit_l);
}
}
inline void kiss_write_packet() {
Serial.write(FEND);
Serial.write(CMD_DATA);
for (uint16_t i = 0; i < read_len; i++) {
uint8_t byte = pbuf[i];
if (byte == FEND) { Serial.write(FESC); byte = TFEND; }
if (byte == FESC) { Serial.write(FESC); byte = TFESC; }
Serial.write(byte);
}
Serial.write(FEND);
read_len = 0;
#if MCU_VARIANT == MCU_ESP32
packet_ready = false;
#endif
}
inline void getPacketData(uint16_t len) {
while (len-- && read_len < MTU) {
pbuf[read_len++] = LoRa.read();
}
}
void ISR_VECT receive_callback(int packet_size) {
if (!promisc) {
// The standard operating mode allows large
// packets with a payload up to 500 bytes,
// by combining two raw LoRa packets.
// We read the 1-byte header and extract
// packet sequence number and split flags
uint8_t header = LoRa.read(); packet_size--;
uint8_t sequence = packetSequence(header);
bool ready = false;
if (isSplitPacket(header) && seq == SEQ_UNSET) {
// This is the first part of a split
// packet, so we set the seq variable
// and add the data to the buffer
read_len = 0;
seq = sequence;
#if MCU_VARIANT != MCU_ESP32
last_rssi = LoRa.packetRssi();
last_snr_raw = LoRa.packetSnrRaw();
#endif
getPacketData(packet_size);
} else if (isSplitPacket(header) && seq == sequence) {
// This is the second part of a split
// packet, so we add it to the buffer
// and set the ready flag.
#if MCU_VARIANT != MCU_ESP32
last_rssi = (last_rssi+LoRa.packetRssi())/2;
last_snr_raw = (last_snr_raw+LoRa.packetSnrRaw())/2;
#endif
getPacketData(packet_size);
seq = SEQ_UNSET;
ready = true;
} else if (isSplitPacket(header) && seq != sequence) {
// This split packet does not carry the
// same sequence id, so we must assume
// that we are seeing the first part of
// a new split packet.
read_len = 0;
seq = sequence;
#if MCU_VARIANT != MCU_ESP32
last_rssi = LoRa.packetRssi();
last_snr_raw = LoRa.packetSnrRaw();
#endif
getPacketData(packet_size);
} else if (!isSplitPacket(header)) {
// This is not a split packet, so we
// just read it and set the ready
// flag to true.
if (seq != SEQ_UNSET) {
// If we already had part of a split
// packet in the buffer, we clear it.
read_len = 0;
seq = SEQ_UNSET;
}
#if MCU_VARIANT != MCU_ESP32
last_rssi = LoRa.packetRssi();
last_snr_raw = LoRa.packetSnrRaw();
#endif
getPacketData(packet_size);
ready = true;
}
if (ready) {
#if MCU_VARIANT != MCU_ESP32
// We first signal the RSSI of the
// recieved packet to the host.
kiss_indicate_stat_rssi();
kiss_indicate_stat_snr();
// And then write the entire packet
kiss_write_packet();
#else
packet_ready = true;
#endif
}
} else {
// In promiscuous mode, raw packets are
// output directly to the host
read_len = 0;
#if MCU_VARIANT != MCU_ESP32
last_rssi = LoRa.packetRssi();
last_snr_raw = LoRa.packetSnrRaw();
getPacketData(packet_size);
// We first signal the RSSI of the
// recieved packet to the host.
kiss_indicate_stat_rssi();
kiss_indicate_stat_snr();
// And then write the entire packet
kiss_write_packet();
#else
getPacketData(packet_size);
packet_ready = true;
#endif
}
}
bool startRadio() {
update_radio_lock();
if (!radio_online) {
if (!radio_locked && hw_ready) {
if (!LoRa.begin(lora_freq)) {
// The radio could not be started.
// Indicate this failure over both the
// serial port and with the onboard LEDs
kiss_indicate_error(ERROR_INITRADIO);
led_indicate_error(0);
return false;
} else {
radio_online = true;
setTXPower();
setBandwidth();
setSpreadingFactor();
setCodingRate();
getFrequency();
LoRa.enableCrc();
LoRa.onReceive(receive_callback);
lora_receive();
// Flash an info pattern to indicate
// that the radio is now on
kiss_indicate_radiostate();
led_indicate_info(3);
return true;
}
} else {
// Flash a warning pattern to indicate
// that the radio was locked, and thus
// not started
radio_online = false;
kiss_indicate_radiostate();
led_indicate_warning(3);
return false;
}
} else {
// If radio is already on, we silently
// ignore the request.
kiss_indicate_radiostate();
return true;
}
}
void stopRadio() {
LoRa.end();
radio_online = false;
}
void update_radio_lock() {
if (lora_freq != 0 && lora_bw != 0 && lora_txp != 0xFF && lora_sf != 0) {
radio_locked = false;
} else {
radio_locked = true;
}
}
bool queueFull() {
return (queue_height >= CONFIG_QUEUE_MAX_LENGTH || queued_bytes >= CONFIG_QUEUE_SIZE);
}
volatile bool queue_flushing = false;
void flushQueue(void) {
if (!queue_flushing) {
queue_flushing = true;
uint16_t processed = 0;
#if MCU_VARIANT == MCU_ESP32
while (!fifo16_isempty(&packet_starts)) {
#else
while (!fifo16_isempty_locked(&packet_starts)) {
#endif
uint16_t start = fifo16_pop(&packet_starts);
uint16_t length = fifo16_pop(&packet_lengths);
if (length >= MIN_L && length <= MTU) {
for (uint16_t i = 0; i < length; i++) {
uint16_t pos = (start+i)%CONFIG_QUEUE_SIZE;
tbuf[i] = packet_queue[pos];
}
transmit(length);
processed++;
}
}
}
queue_height = 0;
queued_bytes = 0;
queue_flushing = false;
}
void transmit(uint16_t size) {
if (radio_online) {
if (!promisc) {
led_tx_on();
uint16_t written = 0;
uint8_t header = random(256) & 0xF0;
if (size > SINGLE_MTU - HEADER_L) {
header = header | FLAG_SPLIT;
}
LoRa.beginPacket();
LoRa.write(header); written++;
for (uint16_t i=0; i < size; i++) {
LoRa.write(tbuf[i]);
written++;
if (written == 255) {
LoRa.endPacket();
LoRa.beginPacket();
LoRa.write(header);
written = 1;
}
}
LoRa.endPacket();
led_tx_off();
lora_receive();
} else {
// In promiscuous mode, we only send out
// plain raw LoRa packets with a maximum
// payload of 255 bytes
led_tx_on();
uint16_t written = 0;
// Cap packets at 255 bytes
if (size > SINGLE_MTU) {
size = SINGLE_MTU;
}
// If implicit header mode has been set,
// set packet length to payload data length
if (!implicit) {
LoRa.beginPacket();
} else {
LoRa.beginPacket(size);
}
for (uint16_t i=0; i < size; i++) {
LoRa.write(tbuf[i]);
written++;
}
LoRa.endPacket();
led_tx_off();
lora_receive();
}
} else {
kiss_indicate_error(ERROR_TXFAILED);
led_indicate_error(5);
}
}
void serialCallback(uint8_t sbyte) {
if (IN_FRAME && sbyte == FEND && command == CMD_DATA) {
IN_FRAME = false;
if (!fifo16_isfull(&packet_starts) && queued_bytes < CONFIG_QUEUE_SIZE) {
uint16_t s = current_packet_start;
int16_t e = queue_cursor-1; if (e == -1) e = CONFIG_QUEUE_SIZE-1;
uint16_t l;
if (s != e) {
l = (s < e) ? e - s + 1 : CONFIG_QUEUE_SIZE - s + e + 1;
} else {
l = 1;
}
if (l >= MIN_L) {
queue_height++;
fifo16_push(&packet_starts, s);
fifo16_push(&packet_lengths, l);
current_packet_start = queue_cursor;
}
}
} else if (sbyte == FEND) {
IN_FRAME = true;
command = CMD_UNKNOWN;
frame_len = 0;
} else if (IN_FRAME && frame_len < MTU) {
// Have a look at the command byte first
if (frame_len == 0 && command == CMD_UNKNOWN) {
command = sbyte;
} else if (command == CMD_DATA) {
cable_state = CABLE_STATE_CONNECTED;
if (sbyte == FESC) {
ESCAPE = true;
} else {
if (ESCAPE) {
if (sbyte == TFEND) sbyte = FEND;
if (sbyte == TFESC) sbyte = FESC;
ESCAPE = false;
}
if (queue_height < CONFIG_QUEUE_MAX_LENGTH && queued_bytes < CONFIG_QUEUE_SIZE) {
queued_bytes++;
packet_queue[queue_cursor++] = sbyte;
if (queue_cursor == CONFIG_QUEUE_SIZE) queue_cursor = 0;
}
}
} else if (command == CMD_FREQUENCY) {
if (sbyte == FESC) {
ESCAPE = true;
} else {
if (ESCAPE) {
if (sbyte == TFEND) sbyte = FEND;
if (sbyte == TFESC) sbyte = FESC;
ESCAPE = false;
}
cbuf[frame_len++] = sbyte;
}
if (frame_len == 4) {
uint32_t freq = (uint32_t)cbuf[0] << 24 | (uint32_t)cbuf[1] << 16 | (uint32_t)cbuf[2] << 8 | (uint32_t)cbuf[3];
if (freq == 0) {
kiss_indicate_frequency();
} else {
lora_freq = freq;
if (op_mode == MODE_HOST) setFrequency();
kiss_indicate_frequency();
}
}
} else if (command == CMD_BANDWIDTH) {
if (sbyte == FESC) {
ESCAPE = true;
} else {
if (ESCAPE) {
if (sbyte == TFEND) sbyte = FEND;
if (sbyte == TFESC) sbyte = FESC;
ESCAPE = false;
}
cbuf[frame_len++] = sbyte;
}
if (frame_len == 4) {
uint32_t bw = (uint32_t)cbuf[0] << 24 | (uint32_t)cbuf[1] << 16 | (uint32_t)cbuf[2] << 8 | (uint32_t)cbuf[3];
if (bw == 0) {
kiss_indicate_bandwidth();
} else {
lora_bw = bw;
if (op_mode == MODE_HOST) setBandwidth();
kiss_indicate_bandwidth();
}
}
} else if (command == CMD_TXPOWER) {
if (sbyte == 0xFF) {
kiss_indicate_txpower();
} else {
int txp = sbyte;
if (txp > 17) txp = 17;
lora_txp = txp;
if (op_mode == MODE_HOST) setTXPower();
kiss_indicate_txpower();
}
} else if (command == CMD_SF) {
if (sbyte == 0xFF) {
kiss_indicate_spreadingfactor();
} else {
int sf = sbyte;
if (sf < 6) sf = 6;
if (sf > 12) sf = 12;
lora_sf = sf;
if (op_mode == MODE_HOST) setSpreadingFactor();
kiss_indicate_spreadingfactor();
}
} else if (command == CMD_CR) {
if (sbyte == 0xFF) {
kiss_indicate_codingrate();
} else {
int cr = sbyte;
if (cr < 5) cr = 5;
if (cr > 8) cr = 8;
lora_cr = cr;
if (op_mode == MODE_HOST) setCodingRate();
kiss_indicate_codingrate();
}
} else if (command == CMD_IMPLICIT) {
set_implicit_length(sbyte);
kiss_indicate_implicit_length();
} else if (command == CMD_RADIO_STATE) {
cable_state = CABLE_STATE_CONNECTED;
if (sbyte == 0xFF) {
kiss_indicate_radiostate();
} else if (sbyte == 0x00) {
stopRadio();
kiss_indicate_radiostate();
} else if (sbyte == 0x01) {
startRadio();
kiss_indicate_radiostate();
}
} else if (command == CMD_STAT_RX) {
kiss_indicate_stat_rx();
} else if (command == CMD_STAT_TX) {
kiss_indicate_stat_tx();
} else if (command == CMD_STAT_RSSI) {
kiss_indicate_stat_rssi();
} else if (command == CMD_RADIO_LOCK) {
update_radio_lock();
kiss_indicate_radio_lock();
} else if (command == CMD_BLINK) {
led_indicate_info(sbyte);
} else if (command == CMD_RANDOM) {
kiss_indicate_random(getRandom());
} else if (command == CMD_DETECT) {
if (sbyte == DETECT_REQ) {
cable_state = CABLE_STATE_CONNECTED;
kiss_indicate_detect();
}
} else if (command == CMD_PROMISC) {
if (sbyte == 0x01) {
promisc_enable();
} else if (sbyte == 0x00) {
promisc_disable();
}
kiss_indicate_promisc();
} else if (command == CMD_READY) {
if (!queueFull()) {
kiss_indicate_ready();
} else {
kiss_indicate_not_ready();
}
} else if (command == CMD_UNLOCK_ROM) {
if (sbyte == ROM_UNLOCK_BYTE) {
unlock_rom();
}
} else if (command == CMD_RESET) {
if (sbyte == CMD_RESET_BYTE) {
hard_reset();
}
} else if (command == CMD_ROM_READ) {
kiss_dump_eeprom();
} else if (command == CMD_ROM_WRITE) {
if (sbyte == FESC) {
ESCAPE = true;
} else {
if (ESCAPE) {
if (sbyte == TFEND) sbyte = FEND;
if (sbyte == TFESC) sbyte = FESC;
ESCAPE = false;
}
cbuf[frame_len++] = sbyte;
}
if (frame_len == 2) {
eeprom_write(cbuf[0], cbuf[1]);
}
} else if (command == CMD_FW_VERSION) {
kiss_indicate_version();
} else if (command == CMD_PLATFORM) {
kiss_indicate_platform();
} else if (command == CMD_MCU) {
kiss_indicate_mcu();
} else if (command == CMD_BOARD) {
kiss_indicate_board();
} else if (command == CMD_CONF_SAVE) {
eeprom_conf_save();
} else if (command == CMD_CONF_DELETE) {
eeprom_conf_delete();
} else if (command == CMD_FB_EXT) {
#if HAS_DISPLAY == true
if (sbyte == 0xFF) {
kiss_indicate_fbstate();
} else if (sbyte == 0x00) {
ext_fb_disable();
kiss_indicate_fbstate();
} else if (sbyte == 0x01) {
ext_fb_enable();
kiss_indicate_fbstate();
}
#endif
} else if (command == CMD_FB_WRITE) {
if (sbyte == FESC) {
ESCAPE = true;
} else {
if (ESCAPE) {
if (sbyte == TFEND) sbyte = FEND;
if (sbyte == TFESC) sbyte = FESC;
ESCAPE = false;
}
cbuf[frame_len++] = sbyte;
}
if (frame_len == 9) {
uint8_t line = cbuf[0];
if (line > 63) line = 63;
int fb_o = line*8;
memcpy(fb+fb_o, cbuf+1, 8);
}
} else if (command == CMD_FB_READ) {
if (sbyte != 0x00) {
kiss_indicate_fb();
}
}
}
}
#if MCU_VARIANT == MCU_ESP32
portMUX_TYPE update_lock = portMUX_INITIALIZER_UNLOCKED;
#endif
void updateModemStatus() {
#if MCU_VARIANT == MCU_ESP32
portENTER_CRITICAL(&update_lock);
#endif
uint8_t status = LoRa.modemStatus();
current_rssi = LoRa.currentRssi();
last_status_update = millis();
#if MCU_VARIANT == MCU_ESP32
portEXIT_CRITICAL(&update_lock);
#endif
if (status & SIG_DETECT == SIG_DETECT) { stat_signal_detected = true; } else { stat_signal_detected = false; }
if (status & SIG_SYNCED == SIG_SYNCED) { stat_signal_synced = true; } else { stat_signal_synced = false; }
if (status & RX_ONGOING == RX_ONGOING) { stat_rx_ongoing = true; } else { stat_rx_ongoing = false; }
if (stat_signal_detected || stat_signal_synced || stat_rx_ongoing) {
if (dcd_count < dcd_threshold) {
dcd_count++;
dcd = true;
} else {
dcd = true;
dcd_led = true;
}
} else {
if (dcd_count > 0) {
dcd_count--;
} else {
dcd_led = false;
}
dcd = false;
}
if (dcd_led) {
led_rx_on();
} else {
led_rx_off();
}
}
void checkModemStatus() {
if (millis()-last_status_update >= status_interval_ms) {
updateModemStatus();
}
}
void validateStatus() {
#if MCU_VARIANT == MCU_1284P
uint8_t boot_flags = OPTIBOOT_MCUSR;
uint8_t F_POR = PORF;
uint8_t F_BOR = BORF;
uint8_t F_WDR = WDRF;
#elif MCU_VARIANT == MCU_2560
uint8_t boot_flags = OPTIBOOT_MCUSR;
if (boot_flags == 0x00) boot_flags = 0x03;
uint8_t F_POR = PORF;
uint8_t F_BOR = BORF;
uint8_t F_WDR = WDRF;
#elif MCU_VARIANT == MCU_ESP32
// TODO: Get ESP32 boot flags
uint8_t boot_flags = 0x02;
uint8_t F_POR = 0x00;
uint8_t F_BOR = 0x00;
uint8_t F_WDR = 0x01;
#endif
if (boot_flags & (1<<F_POR)) {
boot_vector = START_FROM_POWERON;
} else if (boot_flags & (1<<F_BOR)) {
boot_vector = START_FROM_BROWNOUT;
} else if (boot_flags & (1<<F_WDR)) {
boot_vector = START_FROM_BOOTLOADER;
} else {
Serial.write("Error, indeterminate boot vector\r\n");
led_indicate_boot_error();
}
if (boot_vector == START_FROM_BOOTLOADER || boot_vector == START_FROM_POWERON) {
if (eeprom_lock_set()) {
if (eeprom_product_valid() && eeprom_model_valid() && eeprom_hwrev_valid()) {
if (eeprom_checksum_valid()) {
hw_ready = true;
if (eeprom_have_conf()) {
eeprom_conf_load();
op_mode = MODE_TNC;
startRadio();
}
}
} else {
hw_ready = false;
}
} else {
hw_ready = false;
}
} else {
hw_ready = false;
Serial.write("Error, incorrect boot vector\r\n");
led_indicate_boot_error();
}
}
void loop() {
if (radio_online) {
checkModemStatus();
#if MCU_VARIANT == MCU_ESP32
if (packet_ready) {
portENTER_CRITICAL(&update_lock);
last_rssi = LoRa.packetRssi();
last_snr_raw = LoRa.packetSnrRaw();
portEXIT_CRITICAL(&update_lock);
kiss_indicate_stat_rssi();
kiss_indicate_stat_snr();
kiss_write_packet();
}
#endif
if (queue_height > 0) {
if (!dcd_waiting) updateModemStatus();
if (!dcd && !dcd_led) {
if (dcd_waiting) delay(lora_rx_turnaround_ms);
updateModemStatus();
if (!dcd) {
dcd_waiting = false;
flushQueue();
}
} else {
dcd_waiting = true;
}
}
} else {
if (hw_ready) {
led_indicate_standby();
} else {
led_indicate_not_ready();
stopRadio();
}
}
#if MCU_VARIANT == MCU_ESP32
buffer_serial();
if (!fifo_isempty(&serialFIFO)) serial_poll();
#else
if (!fifo_isempty_locked(&serialFIFO)) serial_poll();
#endif
#if HAS_DISPLAY
if (disp_ready) {
update_display();
}
#endif
#if HAS_PMU
if (pmu_ready) {
update_pmu();
}
#endif
}
volatile bool serial_polling = false;
void serial_poll() {
serial_polling = true;
#if MCU_VARIANT != MCU_ESP32
while (!fifo_isempty_locked(&serialFIFO)) {
#else
while (!fifo_isempty(&serialFIFO)) {
#endif
char sbyte = fifo_pop(&serialFIFO);
serialCallback(sbyte);
}
serial_polling = false;
}
#if MCU_VARIANT != MCU_ESP32
#define MAX_CYCLES 20
#else
#define MAX_CYCLES 10
#endif
void buffer_serial() {
if (!serial_buffering) {
serial_buffering = true;
uint8_t c = 0;
while (c < MAX_CYCLES && Serial.available()) {
c++;
#if MCU_VARIANT != MCU_ESP32
if (!fifo_isfull_locked(&serialFIFO)) {
fifo_push_locked(&serialFIFO, Serial.read());
}
#else
if (!fifo_isfull(&serialFIFO)) {
fifo_push(&serialFIFO, Serial.read());
}
#endif
}
serial_buffering = false;
}
}
void serial_interrupt_init() {
#if MCU_VARIANT == MCU_1284P
TCCR3A = 0;
TCCR3B = _BV(CS10) |
_BV(WGM33)|
_BV(WGM32);
// Buffer incoming frames every 1ms
ICR3 = 16000;
TIMSK3 = _BV(ICIE3);
#elif MCU_VARIANT == MCU_2560
// TODO: This should probably be updated for
// atmega2560 support. Might be source of
// reported issues from snh.
TCCR3A = 0;
TCCR3B = _BV(CS10) |
_BV(WGM33)|
_BV(WGM32);
// Buffer incoming frames every 1ms
ICR3 = 16000;
TIMSK3 = _BV(ICIE3);
#elif MCU_VARIANT == MCU_ESP32
// No interrupt-based polling on ESP32
#endif
}
#if MCU_VARIANT == MCU_1284P || MCU_VARIANT == MCU_2560
ISR(TIMER3_CAPT_vect) {
buffer_serial();
}
#endif