Hello everyone,
I'm using an STM32F407 Discovery board to interface with the ADS1115 ADC using SPI. The goal is to read analog voltage values from a potentiometer and transmit the results via UART to a computer.
Hardware Setup: Here's the hardware setup I'm using:
Code : I've configured the SPI and UART peripherals using STM32CubeMX, and I've implemented the necessary functions to communicate with the ADS1115 ADC. The code initializes SPI and UART, sends the appropriate configuration to the ADC, reads the ADC data, and transmits the results via UART. I don't get ADC data on terminal.
I'm looking forward to hearing your thoughts and suggestions. If you've worked on a similar project or have experience with SPI interfacing, your input would be highly appreciated.
Thank you in advance for your help!
I'm using an STM32F407 Discovery board to interface with the ADS1115 ADC using SPI. The goal is to read analog voltage values from a potentiometer and transmit the results via UART to a computer.
Hardware Setup: Here's the hardware setup I'm using:
- STM32F407 Discovery board
- ADS1115 ADC
- Potentiometer
- Connected one end of the potentiometer to A0.
- Connected the wiper (middle terminal) of the potentiometer to A1.
- Connected the other end of the potentiometer to GND.
Code : I've configured the SPI and UART peripherals using STM32CubeMX, and I've implemented the necessary functions to communicate with the ADS1115 ADC. The code initializes SPI and UART, sends the appropriate configuration to the ADC, reads the ADC data, and transmits the results via UART. I don't get ADC data on terminal.
C:
#include "main.h"
#include "usb_host.h"
#include<stdio.h>
#include<string.h>
// ADS1115 configuration command for differential input on AIN0-AIN1
#define ADS1115_CONFIG_CMD 0x83A3 // PGA=1, Single-shot mode, AIN0-AIN1
SPI_HandleTypeDef hspi1;
UART_HandleTypeDef huart2;
uint8_t uartTxBuffer[64];
void SystemClock_Config(void);
static void MX_GPIO_Init(void);
static void MX_SPI1_Init(void);
static void MX_USART2_UART_Init(void);
void MX_USB_HOST_Process(void);
int main(void)
{
HAL_Init();
SystemClock_Config();
MX_GPIO_Init();
MX_SPI1_Init();
MX_USART2_UART_Init();
MX_USB_HOST_Init();
while (1)
{
uint8_t spiTxData[] = {ADS1115_CONFIG_CMD >> 8, ADS1115_CONFIG_CMD & 0xFF};
uint8_t spiRxData[2];
HAL_GPIO_WritePin(CS_I2C_SPI_GPIO_Port, CS_I2C_SPI_Pin, GPIO_PIN_RESET); // Activate Chip Select
HAL_SPI_TransmitReceive(&hspi1, spiTxData, spiRxData, sizeof(spiTxData), HAL_MAX_DELAY);
HAL_GPIO_WritePin(CS_I2C_SPI_GPIO_Port, CS_I2C_SPI_Pin, GPIO_PIN_SET); // Deactivate Chip Select
// Combine received data (16-bit value)
uint16_t adcValue = (spiRxData[0] << 8) | spiRxData[1];
// Convert to human-readable format (millivolts)
float voltage = (adcValue * 4.096) / 32767.0;
// Convert the voltage to a string
snprintf((char *)uartTxBuffer, sizeof(uartTxBuffer), "ADC Value: %d, Voltage: %.2f mV\r\n", adcValue, voltage);
// Send via UART
HAL_UART_Transmit(&huart2, uartTxBuffer, strlen((char *)uartTxBuffer), HAL_MAX_DELAY);
MX_USB_HOST_Process();
}
}
void SystemClock_Config(void)
{
RCC_OscInitTypeDef RCC_OscInitStruct = {0};
RCC_ClkInitTypeDef RCC_ClkInitStruct = {0};
/** Configure the main internal regulator output voltage
*/
__HAL_RCC_PWR_CLK_ENABLE();
__HAL_PWR_VOLTAGESCALING_CONFIG(PWR_REGULATOR_VOLTAGE_SCALE1);
/** Initializes the RCC Oscillators according to the specified parameters
* in the RCC_OscInitTypeDef structure.
*/
RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSE;
RCC_OscInitStruct.HSEState = RCC_HSE_ON;
RCC_OscInitStruct.PLL.PLLState = RCC_PLL_ON;
RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_HSE;
RCC_OscInitStruct.PLL.PLLM = 8;
RCC_OscInitStruct.PLL.PLLN = 336;
RCC_OscInitStruct.PLL.PLLP = RCC_PLLP_DIV2;
RCC_OscInitStruct.PLL.PLLQ = 7;
if (HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK)
{
Error_Handler();
}
/** Initializes the CPU, AHB and APB buses clocks
*/
RCC_ClkInitStruct.ClockType = RCC_CLOCKTYPE_HCLK|RCC_CLOCKTYPE_SYSCLK
|RCC_CLOCKTYPE_PCLK1|RCC_CLOCKTYPE_PCLK2;
RCC_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_PLLCLK;
RCC_ClkInitStruct.AHBCLKDivider = RCC_SYSCLK_DIV1;
RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV4;
RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV2;
if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_5) != HAL_OK)
{
Error_Handler();
}
}
//brief SPI1 Initialization Function
static void MX_SPI1_Init(void)
{
/* SPI1 parameter configuration*/
hspi1.Instance = SPI1;
hspi1.Init.Mode = SPI_MODE_MASTER;
hspi1.Init.Direction = SPI_DIRECTION_2LINES;
hspi1.Init.DataSize = SPI_DATASIZE_8BIT;
hspi1.Init.CLKPolarity = SPI_POLARITY_LOW;
hspi1.Init.CLKPhase = SPI_PHASE_1EDGE;
hspi1.Init.NSS = SPI_NSS_SOFT;
hspi1.Init.BaudRatePrescaler = SPI_BAUDRATEPRESCALER_2;
hspi1.Init.FirstBit = SPI_FIRSTBIT_MSB;
hspi1.Init.TIMode = SPI_TIMODE_DISABLE;
hspi1.Init.CRCCalculation = SPI_CRCCALCULATION_DISABLE;
hspi1.Init.CRCPolynomial = 10;
if (HAL_SPI_Init(&hspi1) != HAL_OK)
{
Error_Handler();
}
}
//brief USART2 Initialization Function
static void MX_USART2_UART_Init(void)
{
/* USER CODE END USART2_Init 1 */
huart2.Instance = USART2;
huart2.Init.BaudRate = 115200;
huart2.Init.WordLength = UART_WORDLENGTH_8B;
huart2.Init.StopBits = UART_STOPBITS_1;
huart2.Init.Parity = UART_PARITY_NONE;
huart2.Init.Mode = UART_MODE_TX_RX;
huart2.Init.HwFlowCtl = UART_HWCONTROL_NONE;
huart2.Init.OverSampling = UART_OVERSAMPLING_16;
if (HAL_UART_Init(&huart2) != HAL_OK)
{
Error_Handler();
}
}
//brief GPIO Initialization Function
static void MX_GPIO_Init(void)
{
GPIO_InitTypeDef GPIO_InitStruct = {0};
/* GPIO Ports Clock Enable */
__HAL_RCC_GPIOE_CLK_ENABLE();
__HAL_RCC_GPIOC_CLK_ENABLE();
__HAL_RCC_GPIOH_CLK_ENABLE();
__HAL_RCC_GPIOA_CLK_ENABLE();
__HAL_RCC_GPIOB_CLK_ENABLE();
__HAL_RCC_GPIOD_CLK_ENABLE();
/*Configure GPIO pin Output Level */
HAL_GPIO_WritePin(CS_I2C_SPI_GPIO_Port, CS_I2C_SPI_Pin, GPIO_PIN_RESET);
/*Configure GPIO pin Output Level */
HAL_GPIO_WritePin(OTG_FS_PowerSwitchOn_GPIO_Port, OTG_FS_PowerSwitchOn_Pin, GPIO_PIN_SET);
/*Configure GPIO pin Output Level */
HAL_GPIO_WritePin(GPIOD, LD4_Pin|LD3_Pin|LD5_Pin|LD6_Pin
|Audio_RST_Pin, GPIO_PIN_RESET);
/*Configure GPIO pin : CS_I2C_SPI_Pin */
GPIO_InitStruct.Pin = CS_I2C_SPI_Pin;
GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP;
GPIO_InitStruct.Pull = GPIO_NOPULL;
GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;
HAL_GPIO_Init(CS_I2C_SPI_GPIO_Port, &GPIO_InitStruct);
/*Configure GPIO pin : OTG_FS_PowerSwitchOn_Pin */
GPIO_InitStruct.Pin = OTG_FS_PowerSwitchOn_Pin;
GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP;
GPIO_InitStruct.Pull = GPIO_NOPULL;
GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;
HAL_GPIO_Init(OTG_FS_PowerSwitchOn_GPIO_Port, &GPIO_InitStruct);
/*Configure GPIO pin : PDM_OUT_Pin */
GPIO_InitStruct.Pin = PDM_OUT_Pin;
GPIO_InitStruct.Mode = GPIO_MODE_AF_PP;
GPIO_InitStruct.Pull = GPIO_NOPULL;
GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;
GPIO_InitStruct.Alternate = GPIO_AF5_SPI2;
HAL_GPIO_Init(PDM_OUT_GPIO_Port, &GPIO_InitStruct);
/*Configure GPIO pin : B1_Pin */
GPIO_InitStruct.Pin = B1_Pin;
GPIO_InitStruct.Mode = GPIO_MODE_EVT_RISING;
GPIO_InitStruct.Pull = GPIO_NOPULL;
HAL_GPIO_Init(B1_GPIO_Port, &GPIO_InitStruct);
/*Configure GPIO pin : BOOT1_Pin */
GPIO_InitStruct.Pin = BOOT1_Pin;
GPIO_InitStruct.Mode = GPIO_MODE_INPUT;
GPIO_InitStruct.Pull = GPIO_NOPULL;
HAL_GPIO_Init(BOOT1_GPIO_Port, &GPIO_InitStruct);
/*Configure GPIO pin : CLK_IN_Pin */
GPIO_InitStruct.Pin = CLK_IN_Pin;
GPIO_InitStruct.Mode = GPIO_MODE_AF_PP;
GPIO_InitStruct.Pull = GPIO_NOPULL;
GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;
GPIO_InitStruct.Alternate = GPIO_AF5_SPI2;
HAL_GPIO_Init(CLK_IN_GPIO_Port, &GPIO_InitStruct);
/*Configure GPIO pins : LD4_Pin LD3_Pin LD5_Pin LD6_Pin
Audio_RST_Pin */
GPIO_InitStruct.Pin = LD4_Pin|LD3_Pin|LD5_Pin|LD6_Pin
|Audio_RST_Pin;
GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP;
GPIO_InitStruct.Pull = GPIO_NOPULL;
GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;
HAL_GPIO_Init(GPIOD, &GPIO_InitStruct);
/*Configure GPIO pins : I2S3_MCK_Pin I2S3_SCK_Pin I2S3_SD_Pin */
GPIO_InitStruct.Pin = I2S3_MCK_Pin|I2S3_SCK_Pin|I2S3_SD_Pin;
GPIO_InitStruct.Mode = GPIO_MODE_AF_PP;
GPIO_InitStruct.Pull = GPIO_NOPULL;
GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;
GPIO_InitStruct.Alternate = GPIO_AF6_SPI3;
HAL_GPIO_Init(GPIOC, &GPIO_InitStruct);
/*Configure GPIO pin : OTG_FS_OverCurrent_Pin */
GPIO_InitStruct.Pin = OTG_FS_OverCurrent_Pin;
GPIO_InitStruct.Mode = GPIO_MODE_INPUT;
GPIO_InitStruct.Pull = GPIO_NOPULL;
HAL_GPIO_Init(OTG_FS_OverCurrent_GPIO_Port, &GPIO_InitStruct);
/*Configure GPIO pin : MEMS_INT2_Pin */
GPIO_InitStruct.Pin = MEMS_INT2_Pin;
GPIO_InitStruct.Mode = GPIO_MODE_EVT_RISING;
GPIO_InitStruct.Pull = GPIO_NOPULL;
HAL_GPIO_Init(MEMS_INT2_GPIO_Port, &GPIO_InitStruct);
/* USER CODE BEGIN MX_GPIO_Init_2 */
/* USER CODE END MX_GPIO_Init_2 */
}
void Error_Handler(void)
{
/* USER CODE BEGIN Error_Handler_Debug */
/* User can add his own implementation to report the HAL error return state */
__disable_irq();
while (1)
{
}
/* USER CODE END Error_Handler_Debug */
}
#ifdef USE_FULL_ASSERT
/**
* @brief Reports the name of the source file and the source line number
* where the assert_param error has occurred.
* @param file: pointer to the source file name
* @param line: assert_param error line source number
* @retval None
*/
void assert_failed(uint8_t *file, uint32_t line)
{
/* USER CODE BEGIN 6 */
/* User can add his own implementation to report the file name and line number,
ex: printf("Wrong parameters value: file %s on line %d\r\n", file, line) */
/* USER CODE END 6 */
}
#endif /* USE_FULL_ASSERT */Thank you in advance for your help!
