zephyr/samples/drivers/uart/echo_bot/src/main.c
Gerard Marull-Paretas 79e6b0e0f6 includes: prefer <zephyr/kernel.h> over <zephyr/zephyr.h>
As of today <zephyr/zephyr.h> is 100% equivalent to <zephyr/kernel.h>.
This patch proposes to then include <zephyr/kernel.h> instead of
<zephyr/zephyr.h> since it is more clear that you are including the
Kernel APIs and (probably) nothing else. <zephyr/zephyr.h> sounds like a
catch-all header that may be confusing. Most applications need to
include a bunch of other things to compile, e.g. driver headers or
subsystem headers like BT, logging, etc.

The idea of a catch-all header in Zephyr is probably not feasible
anyway. Reason is that Zephyr is not a library, like it could be for
example `libpython`. Zephyr provides many utilities nowadays: a kernel,
drivers, subsystems, etc and things will likely grow. A catch-all header
would be massive, difficult to keep up-to-date. It is also likely that
an application will only build a small subset. Note that subsystem-level
headers may use a catch-all approach to make things easier, though.

NOTE: This patch is **NOT** removing the header, just removing its usage
in-tree. I'd advocate for its deprecation (add a #warning on it), but I
understand many people will have concerns.

Signed-off-by: Gerard Marull-Paretas <gerard.marull@nordicsemi.no>
2022-09-05 16:31:47 +02:00

94 lines
2.1 KiB
C

/*
* Copyright (c) 2022 Libre Solar Technologies GmbH
*
* SPDX-License-Identifier: Apache-2.0
*/
#include <zephyr/kernel.h>
#include <zephyr/device.h>
#include <zephyr/drivers/uart.h>
#include <string.h>
/* change this to any other UART peripheral if desired */
#define UART_DEVICE_NODE DT_CHOSEN(zephyr_shell_uart)
#define MSG_SIZE 32
/* queue to store up to 10 messages (aligned to 4-byte boundary) */
K_MSGQ_DEFINE(uart_msgq, MSG_SIZE, 10, 4);
static const struct device *const uart_dev = DEVICE_DT_GET(UART_DEVICE_NODE);
/* receive buffer used in UART ISR callback */
static char rx_buf[MSG_SIZE];
static int rx_buf_pos;
/*
* Read characters from UART until line end is detected. Afterwards push the
* data to the message queue.
*/
void serial_cb(const struct device *dev, void *user_data)
{
uint8_t c;
if (!uart_irq_update(uart_dev)) {
return;
}
while (uart_irq_rx_ready(uart_dev)) {
uart_fifo_read(uart_dev, &c, 1);
if ((c == '\n' || c == '\r') && rx_buf_pos > 0) {
/* terminate string */
rx_buf[rx_buf_pos] = '\0';
/* if queue is full, message is silently dropped */
k_msgq_put(&uart_msgq, &rx_buf, K_NO_WAIT);
/* reset the buffer (it was copied to the msgq) */
rx_buf_pos = 0;
} else if (rx_buf_pos < (sizeof(rx_buf) - 1)) {
rx_buf[rx_buf_pos++] = c;
}
/* else: characters beyond buffer size are dropped */
}
}
/*
* Print a null-terminated string character by character to the UART interface
*/
void print_uart(char *buf)
{
int msg_len = strlen(buf);
for (int i = 0; i < msg_len; i++) {
uart_poll_out(uart_dev, buf[i]);
}
}
void main(void)
{
char tx_buf[MSG_SIZE];
if (!device_is_ready(uart_dev)) {
printk("UART device not found!");
return;
}
/* configure interrupt and callback to receive data */
uart_irq_callback_user_data_set(uart_dev, serial_cb, NULL);
uart_irq_rx_enable(uart_dev);
print_uart("Hello! I'm your echo bot.\r\n");
print_uart("Tell me something and press enter:\r\n");
/* indefinitely wait for input from the user */
while (k_msgq_get(&uart_msgq, &tx_buf, K_FOREVER) == 0) {
print_uart("Echo: ");
print_uart(tx_buf);
print_uart("\r\n");
}
}