![]() You need to wait until I2C line is idle and available for transmission. The problem is that while your line of code to send something over I2C has already been executed, the data is still being physically sent over the line, just because your MCU is much faster than I2C. The point of that blocking part is to not start an I2C communication while another I2C communication is in progress. You should look deeper at why it is there and how can you implement what it does without blocking. It's only a small example, a proof of concept, so there is some blocking in there. Is this (the example you provided) an efficient way of doing things? No. Using the polling method is too slow as blocking the code at a rate of 2kHz is not inefficient, but the interrupt method doesn't seem to be any faster as I still need to hang the system during the aforementioned while loop to check if I2C is ready for another command. I use a 2kHz timer to send an I2C command to read the acc/gyr data-ready register, and if the data is ready for either sensor I read their 6 bytes to get the x/y/z plane information. In my personal example, I want to collect the accelerometer/gyroscope data at the 1.66 kHz rate which the IMU is capable of. Isn't this a very inefficient way to use an interrupt, and no different from using the standard polling method? Both block the main code, so what's the purpose of the interrupt? Under comment #-3- they explain that unless we wait for the I2C state to be ready again, after sending a command, the next command will overwrite the previous one, so they use a while loop which waits for the I2C state to be 'ready' before continuing. ![]() While(HAL_I2C_GetError(&I2cHandle) = HAL_I2C_ERROR_AF) * When Acknowledge failure occurs (Slave don't acknowledge its address) While (HAL_I2C_GetState(&I2cHandle) != HAL_I2C_STATE_READY) Transfer, but application may perform other tasks while transfer operation State of the peripheral if it’s busy you need to wait for the end of currentįor simplicity reasons, this example is just waiting till the end of the * Before starting a new communication transfer, you need to check the current *#-3- Wait for the end of the transfer #*/ * Error_Handler() function is called in case of error. If(HAL_I2C_Master_Transmit_IT(&I2cHandle, (uint16_t)I2C_ADDRESS, (uint8_t*)aTxBuffer, TXBUFFERSIZE)!= HAL_OK) * While the I2C in reception process, user can transmit data through *#-2- Start the transmission process #*/ ![]() Here is a snipped of their code from main.c: /* The board sends the message and expects to receive it back */ Specifically I'll be talking about their 'I2C_TwoBoards_ComIT' example, but all their examples which use the interrupt method have this same quirk. I am using STM32CubeMX and checked out all the example code for my board which is related to I2C. If looking for a different ST Micro datasheet, STM32 datasheet, or microcontroller datasheet, please view our comprehensive library of Arrow Electronics datasheets.I have a Nucleo-F446RE, and I'm trying to get the I2C working with an IMU I have (LSM6DS33). Connect the board to your computer using the USB connector. NUCLEO-F446RE STMicroelectronics Datasheetĭatasheet Snippet: NUCLEO-F446RE PSOC 5LP PROTOTYPING KIT QUICK START GUIDE. Arrow Electronics is an official source for ST Micro datasheets, schematics, and other product documentation. Sometimes referred to as ST Micro and ST Microelectronics, products include STmicroelectronics development boards and STmicroelectronics microcontrollers. Certified STMicroelectronics DistributorĪrrow Electronics is a certified STMicroelectronics distributor, offering a variety of products. Arrow Electronics carries a wide variety of products within these categories. The NUCLEO-F446RE is associated with the following product categories: Microcontrollers, development boards, nucleo board, stm32 nucleo, stm32 board, stm32 nucleo board. This product is part of the STM32 Nucleo family of products. NUCLEO-F446RE by STMicroelectronics Product Video Product Aliases for NUCLEO-F446REĬommon product aliases for the NUCLEO-F446RE include Nucleo F446RE and STMicro Nucleo. ![]() To get started prototyping, ST provides demonstration source code and associated documentation at st.com/stm32nucleo. This configuration is capable of operating at up to 180MHz and features Arduino UNO pin compatibility to enable shield and other peripheral attachments to the STM32 I/Os. The NUCLEO F446RE configuration is built around STmicroelectronics ARM Cortex-M4 STM32R446RE MCU. STMicroelectronics NUCLEO-F446RE Product DescriptionĪs an affordable and flexible way of prototyping with the STM32 family of microcontrollers, the Nucleo family of boards is the first place to start. ![]()
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