STM32F103 and TMC2209 Stepper driver UART connection, no reply.

[TDuck.1]

I have been trying to get a TMC2209 and STM32F103 working over UART for a while now.

I have followed 2 posts ( I am pretty sure correctly ) on this but I can't add them here as I am a new member, they are already on this community.

I have found online that I need to bridge a connection at the back of the driver board I am using, I have done that.

I have also found that for the start UART comms I need to set "GCONF.pdn_disable = 1"

I think that is done correctly in the code below but feel free to correct me.

I have connected a 1K resistor between the Tx and Rx lines as in the datasheet and in one of the posts above.

My problems start with the UART connection I believe.

I have included nothing else in this code so I can just look at getting this working.

I get a 0x05 on Recv[0] each time I run the code but I do not get any other values, I expect to see 0xFF in Recv[1] but I get 0x00.

I get the sync nibble but then nothing else, when I disconnect the Rx and Tx line from the TMC2209 I still get the 0x05 so that makes me thing something is wrong there.

I have tried to use the Receive to idel but I get the same results as the above.

I have played with delays before Receving but then I don't even get the 0x05.

I worried that I might be sending the data in the wrong order ?

All I am trying to do is read back the register I just wrote to.

:

Any pointers would be great on where to go to from here.

Thanks all.

[TDuck.1]

For some reason my code did not get added, here it is :

/* USER CODE BEGIN Header */
/**
 ******************************************************************************
 * @file : main.c
 * @brief : Main program body
 ******************************************************************************
 * @attention
 *
 * Copyright (c) 2023 STMicroelectronics.
 * All rights reserved.
 *
 * This software is licensed under terms that can be found in the LICENSE file
 * in the root directory of this software component.
 * If no LICENSE file comes with this software, it is provided AS-IS.
 *
 ******************************************************************************
 */
/* USER CODE END Header */
/* Includes ------------------------------------------------------------------*/
#include "main.h"
 
/* Private includes ----------------------------------------------------------*/
/* USER CODE BEGIN Includes */
 
/* USER CODE END Includes */
 
/* Private typedef -----------------------------------------------------------*/
/* USER CODE BEGIN PTD */
 
/* USER CODE END PTD */
 
/* Private define ------------------------------------------------------------*/
/* USER CODE BEGIN PD */
/* USER CODE END PD */
 
/* Private macro -------------------------------------------------------------*/
/* USER CODE BEGIN PM */
 
/* USER CODE END PM */
 
/* Private variables ---------------------------------------------------------*/
TIM_HandleTypeDef htim5;
 
UART_HandleTypeDef huart3;
 
/* USER CODE BEGIN PV */
 
/* USER CODE END PV */
 
/* Private function prototypes -----------------------------------------------*/
void SystemClock_Config(void);
static void MX_GPIO_Init(void);
static void MX_USART3_UART_Init(void);
static void MX_TIM5_Init(void);
/* USER CODE BEGIN PFP */
 
/* USER CODE END PFP */
 
/* Private user code ---------------------------------------------------------*/
/* USER CODE BEGIN 0 */
 
/* USER CODE END 0 */
 
/**
 * @brief The application entry point.
 * @retval int
 */
int main(void)
{
 /* USER CODE BEGIN 1 */
 
 /* USER CODE END 1 */
 
 /* MCU Configuration--------------------------------------------------------*/
 
 /* Reset of all peripherals, Initializes the Flash interface and the Systick. */
 HAL_Init();
 
 /* USER CODE BEGIN Init */
 
 /* USER CODE END Init */
 
 /* Configure the system clock */
 SystemClock_Config();
 
 /* USER CODE BEGIN SysInit */
 
 /* USER CODE END SysInit */
 
 /* Initialize all configured peripherals */
 MX_GPIO_Init();
 MX_USART3_UART_Init();
 MX_TIM5_Init();
 /* USER CODE BEGIN 2 */
 
 /* USER CODE END 2 */
 
 /* Infinite loop */
 /* USER CODE BEGIN WHILE */
 
 // basic testing for the TMC2209 driver, sending data on the UART line.
 
 uint8_t send [8]; // total to send
 send[0] = 0x05; // Sysnc part to start Tx
 send[1] = 0x00; // Slave Addr ( to address the different drivers
 send[2] = 0x80; // Addr of the register +
 send[3] = 0x00;
 send[4] = 0x00;
 send[5] = 0x03;
 send[6] = 0x2E;
 send[7] = 0xEF;
 
 HAL_UART_Transmit(&huart3, send, sizeof(send),10);
 
 // ask for a read now from 0x02 ( IFCNT )
 
 
 
 uint8_t Recv[8] = {0};
 uint8_t send2 [4]; // total to send
 send2[0] = 0x05; // Sysnc part to start Tx
 send2[1] = 0x00; // Slave Addr ( to address the different drivers
 send2[2] = 0x00; // Addr of the register +
 send2[3] = 0x48;
 
 HAL_UART_Transmit(&huart3, send2, sizeof(send),10);
 HAL_UART_Receive(&huart3, Recv, 8, 100);
 
 
 
 
 while (1)
 {
 /* USER CODE END WHILE */
 
 /* USER CODE BEGIN 3 */
 }
 /* USER CODE END 3 */
}
 
/**
 * @brief System Clock Configuration
 * @retval None
 */
void SystemClock_Config(void)
{
 RCC_OscInitTypeDef RCC_OscInitStruct = {0};
 RCC_ClkInitTypeDef RCC_ClkInitStruct = {0};
 
 /** Initializes the RCC Oscillators according to the specified parameters
 * in the RCC_OscInitTypeDef structure.
 */
 RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSI;
 RCC_OscInitStruct.HSIState = RCC_HSI_ON;
 RCC_OscInitStruct.HSICalibrationValue = RCC_HSICALIBRATION_DEFAULT;
 RCC_OscInitStruct.PLL.PLLState = RCC_PLL_ON;
 RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_HSI_DIV2;
 RCC_OscInitStruct.PLL.PLLMUL = RCC_PLL_MUL16;
 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_DIV2;
 RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV1;
 
 if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_2) != HAL_OK)
 {
 Error_Handler();
 }
}
 
/**
 * @brief TIM5 Initialization Function
 * @param None
 * @retval None
 */
static void MX_TIM5_Init(void)
{
 
 /* USER CODE BEGIN TIM5_Init 0 */
 
 /* USER CODE END TIM5_Init 0 */
 
 TIM_ClockConfigTypeDef sClockSourceConfig = {0};
 TIM_MasterConfigTypeDef sMasterConfig = {0};
 
 /* USER CODE BEGIN TIM5_Init 1 */
 
 /* USER CODE END TIM5_Init 1 */
 htim5.Instance = TIM5;
 htim5.Init.Prescaler = 50;
 htim5.Init.CounterMode = TIM_COUNTERMODE_UP;
 htim5.Init.Period = 100;
 htim5.Init.ClockDivision = TIM_CLOCKDIVISION_DIV1;
 htim5.Init.AutoReloadPreload = TIM_AUTORELOAD_PRELOAD_ENABLE;
 if (HAL_TIM_Base_Init(&htim5) != HAL_OK)
 {
 Error_Handler();
 }
 sClockSourceConfig.ClockSource = TIM_CLOCKSOURCE_INTERNAL;
 if (HAL_TIM_ConfigClockSource(&htim5, &sClockSourceConfig) != HAL_OK)
 {
 Error_Handler();
 }
 sMasterConfig.MasterOutputTrigger = TIM_TRGO_RESET;
 sMasterConfig.MasterSlaveMode = TIM_MASTERSLAVEMODE_DISABLE;
 if (HAL_TIMEx_MasterConfigSynchronization(&htim5, &sMasterConfig) != HAL_OK)
 {
 Error_Handler();
 }
 /* USER CODE BEGIN TIM5_Init 2 */
 
 /* USER CODE END TIM5_Init 2 */
 
}
 
/**
 * @brief USART3 Initialization Function
 * @param None
 * @retval None
 */
static void MX_USART3_UART_Init(void)
{
 
 /* USER CODE BEGIN USART3_Init 0 */
 
 /* USER CODE END USART3_Init 0 */
 
 /* USER CODE BEGIN USART3_Init 1 */
 
 /* USER CODE END USART3_Init 1 */
 huart3.Instance = USART3;
 huart3.Init.BaudRate = 115200;
 huart3.Init.WordLength = UART_WORDLENGTH_8B;
 huart3.Init.StopBits = UART_STOPBITS_1;
 huart3.Init.Parity = UART_PARITY_NONE;
 huart3.Init.Mode = UART_MODE_TX_RX;
 huart3.Init.HwFlowCtl = UART_HWCONTROL_NONE;
 huart3.Init.OverSampling = UART_OVERSAMPLING_16;
 if (HAL_UART_Init(&huart3) != HAL_OK)
 {
 Error_Handler();
 }
 /* USER CODE BEGIN USART3_Init 2 */
 
 /* USER CODE END USART3_Init 2 */
 
}
 
/**
 * @brief GPIO Initialization Function
 * @param None
 * @retval None
 */
static void MX_GPIO_Init(void)
{
 
 /* GPIO Ports Clock Enable */
 __HAL_RCC_GPIOA_CLK_ENABLE();
 __HAL_RCC_GPIOC_CLK_ENABLE();
 
}
 
/* USER CODE BEGIN 4 */
 
/* USER CODE END 4 */
 
/**
 * @brief This function is executed in case of error occurrence.
 * @retval None
 */
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 */

[Guenael Cadier]

Dear @TDuck.1​ 

Just some ideas to check :

Is there an echo or a loop between your TX and RX pins ? In other words, could it be that when you "get a 0x05 on Recv[0]", this 0x05 is the one you sent from send[0] or send2[0] ?

Second question (if answer to first one is no) : is return code of your HAL_UART_Receive() call equal to HAL_OK ? in such case, it means you receive properly 8 bytes, right ?

Regards

[TDuck.1]

Hi, so I might have an echo as you pointed out, when I try and receive after the frist Tx I still get the 0x05 but that should not happen as Write commands should not reply to anything ( from what I understand in the datasheet )

When I disconnect the Tx and Rx lines from everything then I do not get the 0x05, but when I connect them together with only the 1K resistor but not to the TMC2209 then I get a the 0x05 sync nibble.

Any suggestions on how I would get ride of that ?

I also edited the code to look if the Receive would return HAL_OK but it does not so it is not actually getting anything from the TMC2209.

Thanks for the input.

[Piranha]

The line 126 of your code has a bug.

If you connect the Rx line to the Tx line, isn't it obvious that it receives the transmitted data? ;) One has to either ignore/clear that data or better switch from Tx to Rx mode and back. Probably the HAL_HalfDuplex_EnableTransmitter()/HAL_HalfDuplex_EnableReceiver() functions can help, if you want to stick with the HAL/Cube broken bloatware.

https://community.st.com/s/question/0D53W00001rsnW3SAI/uart-to-interface-with-tmc2209eval-board-problems

https://community.st.com/s/question/0D53W00001TgA9WSAV/for-stm32f407-what-uart-mode-to-set-for-tmc2209-pdnuart-pin

[TDuck.1]

@Piranha​  Thanks for pointing out that bug.

I have seen that the USART line gets pulled down to around 1V when I connect it to the TMC2209, this seems like it could be a problem. I used a different board and found the mod that I did to the back was the cause of this pull down error, but now I am getting a much higher value signal but still nothing coming back from the TMC2209.

Seems like the guide I saw was incorrect about bridging the 2 pads to get UART working.

I have tried with the HAL_HalfDuplex_EnableTransmitter()/HAL_HalfDuplex_EnableReceiver() functions you suggested but using them and the UART port in Half Duplex mode returns nothing, not even that echo off the Tx line.

That and I see in your last posts that the Pin out settings do not really allow this connection :

"Therefore the 1k series resistor is mandatory and the correct pin configuration is: alternate function, push-pull, low speed, pull-up. And this configuration doesn't need to be changed at runtime."

I have set USART3 to Asynchronous mode but now I am unsure if I am sending the correct values for the Register or in the correct order, if you have any input on that I would greatly appreciate it.

[TDuck.1]

Well looking at the Datasheet of my board I actually do need to bridge that pad at the back to get UART connected, but it seems werid that there is such a strong pull down on that line ?

Enough to pull it to 1V from 3.3V

https://www.trinamic.com/fileadmin/assets/Products/Eval_Drawings/TMC2209SilentStepStick_schematic_v20.pdf

[Piranha]

Seems that by default the board is configured for standalone operation. For UART operation I would remove the R1 20k. Internal pull-up/down on STM32 is ~40k, so 1V makes sense.

Also I checked the CRC for your test examples - those are OK.

[veysiadn]

I was also struggling with the UART communication with TMC2209, in my case transmit was always working fine but receive wasn't. I solved my issue by enabling halfduplex transmitter (HAL_HalfDuplex_EnableTransmitter) before sending and enabling halfduplex receiver (HAL_HalfDuplex_EnableReceiver) before receiving. An example driver code is available on my github page (https://github.com/veysiadn/tmc_2209), the other parts of the code is modified from TMC2209 arduino library (https://github.com/janelia-arduino/TMC2209).

Good luck,

Veysi