7、串口

 1 #include <stdint.h>
 2 
 3 #include "nrf.h"
 4 #include "simple_uart.h"
 5 #include "nrf_delay.h"
 6 #include "nrf_gpio.h"
 7 
 8 uint8_t simple_uart_get(void)
 9 {
10     while (NRF_UART0->EVENTS_RXDRDY != 1)
11     {
12         // Wait for RXD data to be received
13     }
14 
15     NRF_UART0->EVENTS_RXDRDY = 0;
16     return (uint8_t)NRF_UART0->RXD;
17 }//等待直到可以直接RXDready，然后将该标志位设置为0，并把收到的数据返回（数据在RXD中）
18 
19 bool simple_uart_get_with_timeout(int32_t timeout_ms, uint8_t *rx_data)
20 {
21     bool ret = true;
22 
23     while (NRF_UART0->EVENTS_RXDRDY != 1)
24     {
25         if (timeout_ms-- >= 0)
26         {
27             // wait in 1ms chunk before checking for status
28             nrf_delay_us(1000);
29         }
30         else
31         {
32             ret = false;
33             break;
34         }
35     }  // Wait for RXD data to be received
36 
37     if (timeout_ms >= 0)
38     {
39         // clear the event and set rx_data with received byte
40         NRF_UART0->EVENTS_RXDRDY = 0;
41         *rx_data = (uint8_t)NRF_UART0->RXD;
42     }
43 
44     return ret;
45 }//等一定时间然后接收
46 
47 void simple_uart_put(uint8_t cr)
48 {
49     NRF_UART0->TXD = (uint8_t)cr;
50 
51     while (NRF_UART0->EVENTS_TXDRDY != 1)
52     {
53         // Wait for TXD data to be sent
54     }
55 
56     NRF_UART0->EVENTS_TXDRDY = 0;
57 }
58 
59 void simple_uart_putstring(const uint8_t *str)
60 {
61     uint_fast8_t i = 0;
62     uint8_t ch = str[i++];
63     while (ch != ‘\0‘)
64     {
65         simple_uart_put(ch);
66         ch = str[i++];
67     }
68 }
69 
70 void simple_uart_config(  uint8_t rts_pin_number,
71                           uint8_t txd_pin_number,
72                           uint8_t cts_pin_number,
73                           uint8_t rxd_pin_number,
74                           bool hwfc)
75 {
76     nrf_gpio_cfg_output(txd_pin_number);
77     nrf_gpio_cfg_input(rxd_pin_number, NRF_GPIO_PIN_NOPULL);
78 
79     NRF_UART0->PSELTXD = txd_pin_number;
80     NRF_UART0->PSELRXD = rxd_pin_number;
81 
82     if (hwfc)
83     {
84         nrf_gpio_cfg_output(rts_pin_number);
85         nrf_gpio_cfg_input(cts_pin_number, NRF_GPIO_PIN_NOPULL);
86         NRF_UART0->PSELCTS = cts_pin_number;
87         NRF_UART0->PSELRTS = rts_pin_number;
88         NRF_UART0->CONFIG  = (UART_CONFIG_HWFC_Enabled << UART_CONFIG_HWFC_Pos);
89     }
90 
91     NRF_UART0->BAUDRATE         = (UART_BAUDRATE_BAUDRATE_Baud38400 << UART_BAUDRATE_BAUDRATE_Pos);
92     NRF_UART0->ENABLE           = (UART_ENABLE_ENABLE_Enabled << UART_ENABLE_ENABLE_Pos);
93     NRF_UART0->TASKS_STARTTX    = 1;
94     NRF_UART0->TASKS_STARTRX    = 1;
95     NRF_UART0->EVENTS_RXDRDY    = 0;
96 }