功能简介 EDMA具备双缓冲模式功能,ADC配合这个功能使用,可有效提高数据转换效率。
本案例将以该EDMA的双缓冲功能为基础,示范如何配置使用ADC的快速转换。
资源准备
1) 硬件环境: 对应产品型号的AT-START BOARD
PA4——3.3V
PA5——0V
PA6——1.5V左右
配置流程
配置ADC使用的GPIO
配置用于普通通道数据传输的DMA
ADC相关配置及设定
普通通道软触发
获取转换数据
GPIO配置函数代码
- static void gpio_config(void)
- {
- gpio_init_type gpio_initstructure;
- crm_periph_clock_enable(CRM_GPIOA_PERIPH_CLOCK, TRUE);
- gpio_default_para_init(&gpio_initstructure);
- /* config adc pin as analog input mode */
- gpio_initstructure.gpio_mode = GPIO_MODE_ANALOG;
- gpio_initstructure.gpio_pins = GPIO_PINS_4 | GPIO_PINS_5 | GPIO_PINS_6;
- gpio_init(GPIOA, &gpio_initstructure);
- }
DMA配置函数代码
- static void edma_config(void)
- {
- edma_init_type edma_init_struct;
- crm_periph_clock_enable(CRM_EDMA_PERIPH_CLOCK, TRUE);
- nvic_irq_enable(EDMA_Stream1_IRQn, 0, 0);
- edma_reset(EDMA_STREAM1);
- edma_default_para_init(&edma_init_struct);
- edma_init_struct.buffer_size = 3;
- edma_init_struct.direction = EDMA_DIR_PERIPHERAL_TO_MEMORY;
- edma_init_struct.memory0_base_addr = (uint32_t)adc1_ordinary_valuetab;
- edma_init_struct.memory_burst_mode = EDMA_MEMORY_SINGLE;
- edma_init_struct.memory_data_width = EDMA_MEMORY_DATA_WIDTH_HALFWORD;
- edma_init_struct.memory_inc_enable = TRUE;
- edma_init_struct.peripheral_base_addr = (uint32_t)&(ADC1->odt);
- edma_init_struct.peripheral_burst_mode = EDMA_PERIPHERAL_SINGLE;
- edma_init_struct.peripheral_data_width = EDMA_PERIPHERAL_DATA_WIDTH_HALFWORD;
- edma_init_struct.peripheral_inc_enable = FALSE;
- edma_init_struct.priority = EDMA_PRIORITY_VERY_HIGH;
- edma_init_struct.loop_mode_enable = FALSE;
- edma_init_struct.fifo_threshold = EDMA_FIFO_THRESHOLD_1QUARTER;
- edma_init_struct.fifo_mode_enable = FALSE;
- edma_init(EDMA_STREAM1, &edma_init_struct);
-
- /* edmamux init and enable */
- edmamux_enable(TRUE);
- edmamux_init(EDMAMUX_CHANNEL1, EDMAMUX_DMAREQ_ID_ADC1);
-
- /* config double buffer mode */
- edma_double_buffer_mode_init(EDMA_STREAM1, (uint32_t)double_adc1_ordinary_valuetab,
- EDMA_MEMORY_0);
-
- /* enable the double memory mode */
- edma_double_buffer_mode_enable(EDMA_STREAM1, TRUE);
-
- /* enable edma full data transfer intterrupt */
- edma_interrupt_enable(EDMA_STREAM1, EDMA_FDT_INT, TRUE);
- edma_stream_enable(EDMA_STREAM1, TRUE);
- }
ADC配置函数代码- static void adc_config(void)
- {
- adc_common_config_type adc_common_struct;
- adc_base_config_type adc_base_struct;
- crm_periph_clock_enable(CRM_ADC1_PERIPH_CLOCK, TRUE);
- nvic_irq_enable(ADC1_2_3_IRQn, 0, 0);
-
- adc_common_default_para_init(&adc_common_struct);
-
- /* config combine mode */
- adc_common_struct.combine_mode = ADC_INDEPENDENT_MODE;
-
- /* config division,adcclk is division by hclk */
- adc_common_struct.div = ADC_HCLK_DIV_17;
-
- /* config common dma mode,it's not useful in independent mode */
- adc_common_struct.common_dma_mode = ADC_COMMON_DMAMODE_DISABLE;
-
- /* config common dma request repeat */
- adc_common_struct.common_dma_request_repeat_state = FALSE;
-
- /* config adjacent adc sampling interval,it's useful for ordinary shifting mode */
- adc_common_struct.sampling_interval = ADC_SAMPLING_INTERVAL_5CYCLES;
-
- /* config inner temperature sensor and vintrv */
- adc_common_struct.tempervintrv_state = FALSE;
-
- /* config voltage battery */
- adc_common_struct.vbat_state = FALSE;
- adc_common_config(&adc_common_struct);
-
- adc_base_default_para_init(&adc_base_struct);
-
- adc_base_struct.sequence_mode = TRUE;
- adc_base_struct.repeat_mode = FALSE;
- adc_base_struct.data_align = ADC_RIGHT_ALIGNMENT;
- adc_base_struct.ordinary_channel_length = 3;
- adc_base_config(ADC1, &adc_base_struct);
-
- adc_resolution_set(ADC1, ADC_RESOLUTION_12B);
-
- /* config ordinary channel */
- adc_ordinary_channel_set(ADC1, ADC_CHANNEL_4, 1, ADC_SAMPLETIME_640_5);
- adc_ordinary_channel_set(ADC1, ADC_CHANNEL_5, 2, ADC_SAMPLETIME_640_5);
- adc_ordinary_channel_set(ADC1, ADC_CHANNEL_6, 3, ADC_SAMPLETIME_640_5);
-
- /* config ordinary trigger source and trigger edge */
- adc_ordinary_conversion_trigger_set(ADC1, ADC_ORDINARY_TRIG_TMR1CH1,
- ADC_ORDINARY_TRIG_EDGE_NONE);
-
- /* config dma mode,it's not useful when common dma mode is use */
- adc_dma_mode_enable(ADC1, TRUE);
-
- /* config dma request repeat,it's not useful when common dma mode is use */
- adc_dma_request_repeat_enable(ADC1, TRUE);
- /* enable adc overflow interrupt */
- adc_interrupt_enable(ADC1, ADC_OCCO_INT, TRUE);
-
- /* adc enable */
- adc_enable(ADC1, TRUE);
- while(adc_flag_get(ADC1, ADC_RDY_FLAG) == RESET);
-
- /* adc calibration */
- adc_calibration_init(ADC1);
- while(adc_calibration_init_status_get(ADC1));
- adc_calibration_start(ADC1);
- while(adc_calibration_status_get(ADC1));
- }
中断服务函数代码
- /* 获取普通通道数据传输完成状态 */
- void EDMA_Stream1_IRQHandler(void)
- {
- if(edma_flag_get(EDMA_FDT1_FLAG) != RESET)
- {
- if(edma_memory_target_get(EDMA_STREAM1))
- {
- double_buffer_is_useful = 0;
- }
- else
- {
- double_buffer_is_useful = 1;
- }
- edma_flag_clear(EDMA_FDT1_FLAG);
- edma_trans_complete_flag = 1;
- }
- }
- /* 获取ADC的溢出状态信息 */
- void ADC1_2_3_IRQHandler(void)
- {
- if(adc_flag_get(ADC1, ADC_OCCO_FLAG) != RESET)
- {
- adc_flag_clear(ADC1, ADC_OCCO_FLAG);
- adc1_overflow_flag++;
- }
- }
main函数代码
- int main(void)
- {
- __IO uint32_t index = 0;
- nvic_priority_group_config(NVIC_PRIORITY_GROUP_4);
- /* config the system clock */
- system_clock_config();
-
- /* init at start board */
- at32_board_init();
- at32_led_off(LED2);
- at32_led_off(LED3);
- at32_led_off(LED4);
- usart1_config(115200);
- gpio_config();
- edma_config();
- adc_config();
- printf("edma_double_buffer \r\n");
- while(1)
- {
- adc_ordinary_software_trigger_enable(ADC1, TRUE);
- while(edma_trans_complete_flag == 0);
- edma_trans_complete_flag = 0;
- if(adc1_overflow_flag != 0)
- {
- /* printf flag when error occur */
- at32_led_on(LED4);
- printf("error occur\r\n");
- printf("adc1_overflow_flag = %d\r\n",adc1_overflow_flag);
- }
- else
- {
- printf("conversion end without error\r\n");
- /* printf data when conversion end without error */
- if(double_buffer_is_useful == 1)
- {
- printf("double_adc1_ordinary_valuetab[0] = 0x%x\r\n", double_adc1_ordinary_valuetab[0]);
- printf("double_adc1_ordinary_valuetab[1] = 0x%x\r\n", double_adc1_ordinary_valuetab[1]);
- printf("double_adc1_ordinary_valuetab[2] = 0x%x\r\n", double_adc1_ordinary_valuetab[2]);
- }
- else
- {
- printf("adc1_ordinary_valuetab[0] = 0x%x\r\n", adc1_ordinary_valuetab[0]);
- printf("adc1_ordinary_valuetab[1] = 0x%x\r\n", adc1_ordinary_valuetab[1]);
- printf("adc1_ordinary_valuetab[2] = 0x%x\r\n", adc1_ordinary_valuetab[2]);
- }
- }
- printf("\r\n");
- delay_sec(1);
- }
- }
实验效果 可通过串口打印查看实现效果,如下图所示,ADC转换数据被硬件循环的存储到EDMA设定的两个buffer 内了。
串口配置
Baud rate:115200
Stop bits:1
Data bits:8
Parity:None
ADC双Buffer实验结果
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