Interfacing of TF Series LiDAR with ESP32 Micro-controller

Benewake

Arduino IDE

Espressif Systems

TF LiDARs

<html><body><h3>Interfacing of TF Series LiDAR with ESP32 Micro-controller</h3><h3>Introduction:</h3>In this tutorial, the interfacing of Benewake Single Point LiDARs with ESP32 (ESP32-WROOM-32) is discussed. First of all, the pin-out details of ESP32 will be discussed in details. Next step will be how to install the required library of ESP32 in order to write and burn the code using Arduino IDE. Connection details and code is also the part of this tutorial. The ESP32 chip comes with 48 pins with multiple functions. Not all pins are exposed in all ESP32 development boards, and there are some pins that cannot be used. This tutorial will identify all those pins which can be used for different types of interfacing. The figure below illustrates ESP-WROOM-32. <figure><img src="https://projects.arduinocontent.cc/8a74fef7-b028-42fe-8e86-aeb325047318.png"/><figcaption></figcaption></figure>Note: not all GPIOs are accessible in all development boards, but each specific GPIO works in the same way regardless of the development board you’re using. ESP32 Peripherals The ESP32 peripherals include: <ol><li>18 Analog-to-Digital Converter (ADC) channels </li><li>3 SPI interfaces </li><li>3 UART interfaces </li><li>2 I2C interfaces </li><li>16 PWM output channels </li><li>2 Digital-to-Analog Converters (DAC) </li><li>2 I2S interfaces </li><li>10 Capacitive sensing GPIOs </li></ol>The pins highlighted in green are OK to use. The ones highlighted in yellow are OK to use, but you need to pay attention because they may have unexpected behavior mainly at boot. The pins highlighted in red are not recommended to use as inputs or outputs. <figure><img src="https://projects.arduinocontent.cc/0e748233-8dce-44ac-8d15-15f656e59588.png"/><figcaption></figcaption></figure>GPIO Details of ESP32: <figure><img src="https://projects.arduinocontent.cc/9d32b30f-7d6b-40e7-8a00-68f8d576ccda.png"/><figcaption></figcaption></figure> <figure><img src="https://projects.arduinocontent.cc/d1bec6ee-0233-4756-9cfa-959ca612a185.png"/><figcaption></figcaption></figure>Input only pins GPIOs 34 to 39 are GPIs – input only pins. These pins don’t have internal pull-ups or pull-down resistors. They can’t be used as outputs, so use these pins only as inputs: <ol><li>GPIO 34 </li><li>GPIO 35 </li><li>GPIO 36 </li><li>GPIO 39 </li></ol><h3>Installing ESP32 Library using Arduino IDE:</h3>To install the ESP32 board in your Arduino IDE, follow these next instructions: 1. In your Arduino IDE, go to File&gt; Preferences <figure><img src="https://projects.arduinocontent.cc/3c393999-81f4-4aa4-9da3-18e1af55ce71.png"/><figcaption></figcaption></figure>2. Enter https://dl.espressif.com/dl/package_esp32_index.json into the “Additional Board Manager URLs” field as shown in the figure below. Then, click the “OK” button: <figure><img src="https://projects.arduinocontent.cc/3f00260e-0c2e-42cd-b6dd-90204ba88be1.png"/><figcaption></figcaption></figure>3. Open the Boards Manager. Go to Tools &gt; Board &gt; Boards Manager… <figure><img src="https://projects.arduinocontent.cc/04d1fcf8-5811-4881-9c2f-c568241a83b7.png"/><figcaption></figcaption></figure>4. Search for ESP32 and press install button for the “ESP32 by Espressif Systems“: <figure><img src="https://projects.arduinocontent.cc/486a6f4e-760a-4b78-831f-158a74df98d9.png"/><figcaption></figcaption></figure>5. That’s it. It should be installed after a few seconds. <figure><img src="https://projects.arduinocontent.cc/39e0bb99-0a72-41ad-be49-d6d2226aa95e.png"/><figcaption></figcaption></figure><h3>Troubleshooting</h3>If you try to upload a new sketch to your ESP32 and you get this error message “A fatal error occurred: Failed to connect to ESP32: Timed out… Connecting…“. It means that your ESP32 is not in flashing/uploading mode. In my case it worked several times without any issue. Having the right board name and COM port selected, follow these steps: <ol><li>Hold-down the “BOOT” button in your ESP32 board </li></ol><figure><img src="https://projects.arduinocontent.cc/c1ecf374-9bb4-4dde-ab54-f10632a3e20b.png"/><figcaption></figcaption></figure><ol><li>Press the “Upload” button in the Arduino IDE to upload your sketch. </li><li>After you see the “Connecting….” message in your Arduino IDE, release the finger from the “BOOT” button: </li></ol><figure><img src="https://projects.arduinocontent.cc/67d05abc-bb59-4eb0-b5c9-fbd015ceccf3.png"/><figcaption></figcaption></figure><ol><li>After that, you should see the “Done uploading” message </li></ol>That’s it. Your ESP32 should have the new sketch running. Press the “ENABLE” button to restart the ESP32 and run the new uploaded sketch. You’ll also have to repeat that button sequence every time you want to upload a new sketch. Connecting LiDAR with ESP32: <figure><img src="https://projects.arduinocontent.cc/bd36775f-4753-4dbf-992c-c689f494253b.png"/><figcaption></figcaption></figure>In this tutorial, I used TFmini-S as an example but all other TF Series LiDARs can be interfaced in the same way by connecting the right wires because the code part and protocol are same. NOTE: Here you should notice that I used external power supply of 5V in the diagram, actually 3.3V of ESP32 can be used (I did test with 3.3V) but using 3.3V will reduce the accuracy of measurement because the rated voltage of TF series LiDAR is 5V. So, if you want to get documented accuracy of measurement you need to provide 5V. I used hardware serial port of ESP32. In order to use other pins for serial communication, addition of Software Serial Library will be required. This code is uploaded to GitHub repository[ https://github.com/ibrahimqazi/TFmini-S-interfacing-with-ESP32]. This section defines pins, defining necessary variables, initialization of serial ports that are required in order to process the LiDAR data. <figure><img src="https://projects.arduinocontent.cc/125e05fe-47a0-4d4b-a82e-674a451c257e.png"/><figcaption></figcaption></figure>Next section includes processing LiDARs Data and printing it to the terminal. <figure><img src="https://projects.arduinocontent.cc/816141d7-146d-4ad2-aaa0-ca9bdd9d5e3f.png"/><figcaption></figcaption></figure> <figure><img src="https://projects.arduinocontent.cc/b9eae17a-8549-478b-a068-2d30d17fed7b.png"/><figcaption></figcaption></figure> <figure><img src="https://projects.arduinocontent.cc/062a3cb1-e853-4858-95be-da0ab6ade93e.png"/><figcaption></figcaption></figure> <figure><img src="https://projects.arduinocontent.cc/c1a52a66-ee9f-4b46-99d6-fd23efc6a6c8.png"/><figcaption></figcaption></figure>While burning the code to ESP32, the board needs to be chosen is ESP32 Dev Module. After successfully burning the code, you should be see the data in Serial Monitor of Arduino IDE or any other serial port tool can be used. The data can be displayed using Serial Monitor of Arduino IDE or any other Serial Port Tool. <figure><img src="https://projects.arduinocontent.cc/2005ce08-9a90-4ed9-9832-25365cab54b9.png"/><figcaption></figcaption></figure>For more information about TF series LiDARs, see https://benewake.short.gy/lidar. </body></html>

Interfacing of TF Series LiDAR with ESP32 Micro-controller

This blog describes the interfacing of TF Series LiDAR with ESP32 Micro-controller