
// ****************************************************************************
//
//                                 Main code
//
// ****************************************************************************
// This program
// - Uses UART1 (the spare UART, by default) to transmit some text
// - Uses a PIO state machine to receive that text
// - Prints out the received text to the default console (UART0)
// This might require some reconfiguration on boards where UART1 is the
// default UART.

#include "include.h"

#define SERIAL_BAUD PICO_DEFAULT_UART_BAUD_RATE
#define HARD_UART_INST uart1

// You'll need a wire from GPIO4 -> GPIO3
#define HARD_UART_TX_PIN 4
#define PIO_RX_PIN 3

// Ask core 1 to print a string, to make things easier on core 0
void core1_main()
{
	const char *s = (const char *) multicore_fifo_pop_blocking();
	uart_puts(HARD_UART_INST, s);
}

int main()
{
	// Console output (also a UART, yes it's confusing)
	setup_default_uart();
	printf("Starting PIO UART RX example\n");

	// Set up the hard UART we're going to use to print characters
	uart_init(HARD_UART_INST, SERIAL_BAUD);
	gpio_set_function(HARD_UART_TX_PIN, GPIO_FUNC_UART);

	// Set up the state machine we're going to use to receive them.
	PIO pio = pio0;
	uint sm = 0;
	uint offset = pio_add_program(pio, &uart_rx_program);
	uart_rx_program_init(pio, sm, offset, PIO_RX_PIN, SERIAL_BAUD);

	// Tell core 1 to print some text to uart1 as fast as it can
	multicore_launch_core1(core1_main);
	const char *text = "Hello, world from PIO! (Plus 2 UARTs and 2 cores, for complex reasons)\n";
	multicore_fifo_push_blocking((uint32_t) text);

	// Echo characters received from PIO to the console
	while (true)
	{
		char c = uart_rx_program_getc(pio, sm);
		putchar(c);
	}
}
