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62 lines
2.0 KiB
C

/**
* Copyright (c) 2021 mjcross
*
* SPDX-License-Identifier: BSD-3-Clause
*/
#include <stdio.h>
#include "pico/stdlib.h"
#include "nec_transmit.h" // include the library headers
#include "nec_receive.h"
// Infrared loopback example ('NEC' format)
//
// Need to connect an IR LED to GPIO 14 via a suitable series resistor (e.g. 1.5k)
// and an active-low IR detector to GPIO 15 (e.g. VS1838b)
//
// Output is sent to stdout
int main() {
stdio_init_all();
PIO pio = pio0; // choose which PIO block to use (RP2040 has two: pio0 and pio1)
uint tx_gpio = 14; // choose which GPIO pin is connected to the IR LED
uint rx_gpio = 15; // choose which GPIO pin is connected to the IR detector
// configure and enable the state machines
int tx_sm = nec_tx_init(pio, tx_gpio); // uses two state machines, 16 instructions and one IRQ
int rx_sm = nec_rx_init(pio, rx_gpio); // uses one state machine and 9 instructions
if (tx_sm == -1 || rx_sm == -1) {
printf("could not configure PIO\n");
return -1;
}
// transmit and receive frames
uint8_t tx_address = 0x00, tx_data = 0x00, rx_address, rx_data;
while (true) {
// create a 32-bit frame and add it to the transmit FIFO
uint32_t tx_frame = nec_encode_frame(tx_address, tx_data);
pio_sm_put(pio, tx_sm, tx_frame);
printf("\nsent: %02x, %02x", tx_address, tx_data);
// allow time for the frame to be transmitted (optional)
sleep_ms(100);
// display any frames in the receive FIFO
while (!pio_sm_is_rx_fifo_empty(pio, rx_sm)) {
uint32_t rx_frame = pio_sm_get(pio, rx_sm);
if (nec_decode_frame(rx_frame, &rx_address, &rx_data)) {
printf("\treceived: %02x, %02x", rx_address, rx_data);
} else {
printf("\treceived: %08x", rx_frame);
}
}
sleep_ms(900);
tx_data += 1;
}
}