在使用GD32串口接收数据的过程中，遇到了数据无法接收的问题，在导师的帮助下，需要调用usart_flag_get函数来使RBNE置1，RBNE:读数据时缓冲区非空，当数据缓存区接收到来自移位寄存器的数据时，该位置1. 0:读数据缓存区为空， 1：读数据缓存区不为空。主要代码如下：
while(1) {
delay_1ms(400);
gd_eval_led_on(LED3);
delay_1ms(400);
gd_eval_led_off(LED3);
for ( i =0;i<16;i++) {
vref_value[i]=adc_value[i]*3.3/4096;
}
**if(usart_flag_get(USART0,USART_FLAG_RBNE)==1) {
if(usart_data_receive(USART0)=='0') {**
delay_1ms(400);
gd_eval_led_on(LED2);
printf("通道0的值为%5.3f\r\n",vref_value[0]);
}
使用GD32串口接收ADC通道的值代码如下：
/*GD32通过串口接收ADC通道的值，并打印出 */
/*
\file main.c
\brief USART printf demo
*/
/*
Copyright (C) 2017 GigaDevice
2017-06-23, V1.0.0, demo for GD32F30x
*/
#include "gd32f30x.h"
#include "gd32f303c_eval.h"
#include "systick.h"
#include <stdio.h>
#include "gd32f30x_it.h"
uint16_t i;
float adc_value[16];
float vref_value[16];
uint16_t j;
void led_init(void);
void led_flash(int times);
void rcu_config(void);
void gpio_config(void);
void adc_config();
uint16_t adc_channel_sample(uint8_t channel);
/*!
\brief main function
\param[in] none
\param[out] none
\retval none
*/
int main(void)
{
/* initialize the LEDs */
led_init();
/* configure systick */
systick_config(); //系统滴答定时器配置
/* flash the LEDs for 1 time */
led_flash(1);
/* configure EVAL_COM1 */
gd_eval_com_init(EVAL_COM1);
rcu_config();
gpio_config();
adc_config();
/* configure WAKEUP key */
gd_eval_key_init(KEY_WAKEUP, KEY_MODE_GPIO);
/* output a message on hyperterminal using printf function */
printf("\r\n USART receive example: please transmit a number \r\n");
/* wait for completion of USART transmission */
adc_value[0]=adc_channel_sample(ADC_CHANNEL_0);
adc_value[1]=adc_channel_sample(ADC_CHANNEL_1);
adc_value[2]=adc_channel_sample(ADC_CHANNEL_2);
adc_value[3]=adc_channel_sample(ADC_CHANNEL_3);
adc_value[4]=adc_channel_sample(ADC_CHANNEL_4);
adc_value[5]=adc_channel_sample(ADC_CHANNEL_5);
adc_value[6]=adc_channel_sample(ADC_CHANNEL_6);
adc_value[7]=adc_channel_sample(ADC_CHANNEL_7);
adc_value[8]=adc_channel_sample(ADC_CHANNEL_8);
adc_value[9]=adc_channel_sample(ADC_CHANNEL_9);
adc_value[10]=adc_channel_sample(ADC_CHANNEL_10);
adc_value[11]=adc_channel_sample(ADC_CHANNEL_11);
adc_value[12]=adc_channel_sample(ADC_CHANNEL_12);
adc_value[13]=adc_channel_sample(ADC_CHANNEL_13);
adc_value[14]=adc_channel_sample(ADC_CHANNEL_14);
adc_value[15]=adc_channel_sample(ADC_CHANNEL_15);
while(1){
delay_1ms(400);
gd_eval_led_on(LED3);
delay_1ms(400);
gd_eval_led_off(LED3);
for ( i =0;i<16;i++) {
vref_value[i]=adc_value[i]*3.3/4096;
}
//printf("请输入一个数\r\n");
//scanf("%d\r\n",&j);
if(usart_flag_get(USART0,USART_FLAG_RBNE)==1)
{
if(usart_data_receive(USART0)=='0'){
delay_1ms(400);
gd_eval_led_on(LED2);
// printf("%d\r\n",usart_data_receive(USART0));
printf("通道0的值为%5.3f\r\n",vref_value[0]);
}
else if(usart_data_receive(USART0)==1) {
printf("通道1的值为%5.3f\r\n",vref_value[1]);
}
else if(usart_data_receive(USART0)==2){
printf("通道2的值为%5.3f\r\n",vref_value[2]);
}
else if(usart_data_receive(USART0)==3) {
printf("通道3的值为%5.3f\r\n",vref_value[3]);
}
else if(usart_data_receive(USART0)==4) {
printf("通道4的值为%5.3f\r\n",vref_value[4]);
}
else if(usart_data_receive(USART0)==5) {
printf("通道5的值为%5.3f\r\n",vref_value[5]);
}
else if(usart_data_receive(USART0)==6) {
printf("通道6的值为%5.3f\r\n",vref_value[6]);
}
else if(usart_data_receive(USART0)==7) {
printf("通道7的值为%5.3f\r\n",vref_value[7]);
}
else if(usart_data_receive(USART0)==8) {
printf("通道8的值为%5.3f\r\n",vref_value[8]);
}
else if(usart_data_receive(USART0)==9) {
printf("通道9的值为%5.3f\r\n",vref_value[9]);
}
else if(usart_data_receive(USART0)==10) {
printf("通道10的值为%5.3f\r\n",vref_value[10]);
}
else if(usart_data_receive(USART0)==11) {
printf("通道11的值为%5.3f\r\n",vref_value[11]);
}
else if(usart_data_receive(USART0)==12) {
printf("通道12的值为%5.3f\r\n",vref_value[12]);
}
else if(usart_data_receive(USART0)==13) {
printf("通道13的值为%5.3f\r\n",vref_value[13]);
}
else if(usart_data_receive(USART0)==14) {
printf("通道14的值为%5.3f\r\n",vref_value[14]);
}
else if (usart_data_receive(USART0)==15){
printf("通道15的值为%5.3f\r\n",vref_value[15]);
}
else {
printf("receive error\r\n");
}
}
}
}
void rcu_config(void)
{
/* enable GPIOA clock */
rcu_periph_clock_enable(RCU_GPIOA);
rcu_periph_clock_enable(RCU_GPIOB);
rcu_periph_clock_enable(RCU_GPIOC);
/* enable ADC clock */
rcu_periph_clock_enable(RCU_ADC0);
/* config ADC clock */
rcu_adc_clock_config(RCU_CKADC_CKAPB2_DIV6);
}
void gpio_config(void)
{
/* config the GPIO as analog mode */
gpio_init(GPIOA, GPIO_MODE_AIN, GPIO_OSPEED_10MHZ, GPIO_PIN_0);
gpio_init(GPIOA, GPIO_MODE_AIN, GPIO_OSPEED_10MHZ, GPIO_PIN_1);
gpio_init(GPIOA, GPIO_MODE_AIN, GPIO_OSPEED_10MHZ, GPIO_PIN_2);
gpio_init(GPIOA, GPIO_MODE_AIN, GPIO_OSPEED_10MHZ, GPIO_PIN_3);
gpio_init(GPIOA, GPIO_MODE_AIN, GPIO_OSPEED_10MHZ, GPIO_PIN_4);
gpio_init(GPIOA, GPIO_MODE_AIN, GPIO_OSPEED_10MHZ, GPIO_PIN_5);
gpio_init(GPIOA, GPIO_MODE_AIN, GPIO_OSPEED_10MHZ, GPIO_PIN_6);
gpio_init(GPIOA, GPIO_MODE_AIN, GPIO_OSPEED_10MHZ, GPIO_PIN_7);
gpio_init(GPIOB, GPIO_MODE_AIN, GPIO_OSPEED_10MHZ, GPIO_PIN_0);
gpio_init(GPIOB, GPIO_MODE_AIN, GPIO_OSPEED_10MHZ, GPIO_PIN_1);
gpio_init(GPIOC, GPIO_MODE_AIN, GPIO_OSPEED_10MHZ, GPIO_PIN_0);
gpio_init(GPIOC, GPIO_MODE_AIN, GPIO_OSPEED_10MHZ, GPIO_PIN_1);
gpio_init(GPIOC, GPIO_MODE_AIN, GPIO_OSPEED_10MHZ, GPIO_PIN_2);
gpio_init(GPIOC, GPIO_MODE_AIN, GPIO_OSPEED_10MHZ, GPIO_PIN_3);
gpio_init(GPIOC, GPIO_MODE_AIN, GPIO_OSPEED_10MHZ, GPIO_PIN_4);
gpio_init(GPIOC, GPIO_MODE_AIN, GPIO_OSPEED_10MHZ, GPIO_PIN_5);
}
void adc_config(void)
{
/* ADC mode config */
adc_mode_config(ADC_MODE_FREE);
/* ADC data alignment config */
adc_data_alignment_config(ADC0, ADC_DATAALIGN_RIGHT);
/* ADC channel length config */
adc_channel_length_config(ADC0, ADC_REGULAR_CHANNEL, 1U);
/* ADC trigger config */
adc_external_trigger_source_config(ADC0, ADC_REGULAR_CHANNEL, ADC0_1_2_EXTTRIG_REGULAR_NONE);
/* ADC external trigger config */
adc_external_trigger_config(ADC0, ADC_REGULAR_CHANNEL, ENABLE);
/* enable ADC interface */
adc_enable(ADC0);
delay_1ms(1U);
/* ADC calibration and reset calibration */
adc_calibration_enable(ADC0);
}
uint16_t adc_channel_sample(uint8_t channel)
{
/* ADC regular channel config */
adc_regular_channel_config(ADC0, 0U, channel, ADC_SAMPLETIME_7POINT5); //adc规则通道配置
/* ADC software trigger enable */
adc_software_trigger_enable(ADC0, ADC_REGULAR_CHANNEL); //adc软件触发使能
/* wait the end of conversion flag */
while(!adc_flag_get(ADC0, ADC_FLAG_EOC)); //等待转换完成标志
/* clear the end of conversion flag */
adc_flag_clear(ADC0, ADC_FLAG_EOC); //清除转换完成标志
/* return regular channel sample value */
return (adc_regular_data_read(ADC0)); //返回规则通道样品值
}
/*!
\brief initialize the LEDs
\param[in] none
\param[out] none
\retval none
*/
void led_init(void)
{
gd_eval_led_init(LED2);
gd_eval_led_init(LED3);
gd_eval_led_init(LED4);
gd_eval_led_init(LED5);
}
/*!
\brief flash the LEDs for test
\param[in] times: times to flash the LEDs
\param[out] none
\retval none
*/
void led_flash(int times)
{
int i;
for(i=0; i<times; i++){
/* delay 400 ms */
delay_1ms(400);
/* turn on LEDs */
gd_eval_led_on(LED2);
gd_eval_led_on(LED3);
gd_eval_led_on(LED4);
gd_eval_led_on(LED5);
/* delay 400 ms */
delay_1ms(400);
/* turn off LEDs */
gd_eval_led_off(LED2);
gd_eval_led_off(LED3);
gd_eval_led_off(LED4);
gd_eval_led_off(LED5);
}
}
/* retarget the C library printf function to the USART */
int fputc(int ch, FILE *f)
{
usart_data_transmit(EVAL_COM1, (uint8_t)ch);
while(RESET == usart_flag_get(EVAL_COM1, USART_FLAG_TBE));
return ch;
}