AT

 

AT commands testing on ESP32-WROOM-32

ESP32-WROOM-32 PINOUT DIAGRAM

 

ESP32-WROOM-32 - ESP32-WROOM-32 module soldered to the development board. Optionally ESP32-WROOM-32D, ESP32-WROOM-32U or ESP32-SOLO-1 module may be soldered instead of the ESP32-WROOM-32.

USB-UART Bridge - A single chip USB-UART bridge provides up to 3 Mbps transfers rates.

BOOT button - Download button: holding down the Boot button and pressing the EN button initiates the firmware download mode. Then user can download firmware through the serial port.

EN button - Reset button: pressing this button resets the system.

Micro USB Port - USB interface. It functions as the power supply for the board and the communication interface between PC and the ESP module.

TX0, TX2 - transmit pin. GPIO pin

RX0, RX2  - receive pin.  GPIO pin

3V3 (or 3V or 3.3V) - power supply pin (3-3.6V). 

GND - ground pin.

EN - Chip enable. Keep it on high (3.3V) for normal operation.

Vin - External power supply 5VDC.

1.   Uploading AT firmware/Firmware upgrade

CONNECTIONS :

·       Attach USB cable one side to ESP32-WROOM-32

·       Connect the another end PC/LAPTOP

 

Shown below

2. Using USB to TTL converter for AT communication

ESP32-WROOM-32 firmware versions

 

ESP32-WROOM-32 AT Bin V1.1.1 2018.07.11

ESP32-WROOM-32 AT Bin V1.1 2018.06.13

ESP32-WROOM-32 AT Bin V1.0 2017.11.17

ESP32-WROOM-32 AT Bin V0.10 2017.06.14

 

 

1.     Do wiring for uploading AT firmware/firmware update.

2.     Download Flash Download Tools (ESP8266 & ESP32) from espressif.com.  

The ESP32 Flash Download Tool, just like the ESP8266 download tool, is the official Espressif Download tool that runs on Windows platform. The tool can be used to modify and generate init BINs, generate consolidated BIN files or program multiple chips for production runs.

The tool uses COM port to send BIN files from PC to the ESP32, which then flashes the data to the primary flash chip.

The ESP32 Flash Download Tool, just like the ESP8266 download tool, is the official Espressif Download tool that runs on Windows platform. The tool can be used to modify and generate init BINs, generate consolidated BIN files or program multiple chips for production runs.
The tool uses COM port to send BIN files from PC to the ESP32, which then flashes the data to the primary flash chip.

3.     Download and unzip the latest AT firmware for your module (Check which module you have, for example we have ESP32-WROOM-32). We used this firmware here: ESP32-WROOM-32 AT Bin V1.1.1 2018.07.11

4.     Go to the folder ESP32-WROOM-32_AT_V1.1.1 and find file named download.config. 

 

• You can open it with Notepad program. This file has configuration for ESP32 download tool: --flash_mode dio --flash_freq 40m --flash_size detect 0x1000 bootloader/bootloader.bin 0x20000 at_customize.bin 0x21000 customized_partitions/ble_data.bin 0x24000 customized_partitions/server_cert.bin 0x26000 customized_partitions/server_key.bin 0x28000 customized_partitions/server_ca.bin 0x2a000 customized_partitions/client_cert.bin 0x2c000 customized_partitions/client_key.bin 0x2e000 customized_partitions/client_ca.bin 0xf000 phy_init_data.bin 0x100000 esp-at.bin 0x8000 partitions_at.bin.
• You will need to upload 9 files to your ESP32 development board: 0x1000 bootloader/bootloader.bin 0x20000 at_customize.bin 0x21000 customized_partitions/ble_data.bin 0x24000 customized_partitions/server_cert.bin 0x26000 customized_partitions/server_key.bin 0x28000 customized_partitions/server_ca.bin 0xf000 phy_init_data.bin 0x100000 esp-at.bin 0x8000 partitions_at.bin
• Unzip, open FLASH_DOWNLOAD_TOOLS_V3.6.4 folder and double-click on ESPFlashDownloadTool_v3.6.4.exe
• Click on ESP32 DownloadTool button. Select SPIDownload tab. Set configuration as shown below:

 

 

 

 

 

 

 

AT commands firmware for memory locations

1. bootloader.bin:0x1000

2. at_customize.bin:0x20000

3. server_cert.bin:0x24000

4. server_key.bin:0x26000

5. server_ca.bin:0x28000

6. client_cert.bin:0x2a000

7. client_key.bin:0x2c000

8. client_ca.bin:0x2e000

9. phy_init_data.bin:0xf000

10. esp-at.bin:0x100000

11. partitions_at.bin:0x8000

Download tool

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

After flashing the firmware

 

 

 

 

 

 

 

 

 

 

 

 

 

To communicate (use AT commands) with ESP32 development board you need USB to TTL converter. 

For using this USB to UART Converter you need a software tool. You can use different software tools: Terminal, USR-TCP232-Test V1.4, AiThinker_Serial_Tool_V1.2.3, coolterm, sscom3.2 , KiTTY, putty,tera term, Access port and so on. We recommend you to use AiThinker_Serial_Tool_V1.2.3 or sscom3.2, as you can save your AT commands and it's very easy to use.

• Do wiring for using USB to TTL converter for AT communication.
• Plug your USB to TTL converter into your PC USB port. Download and install drivers. See more info here.
• Download and install software tool. We will use AiThinker_Serial_Tool_V1.2.3 here.
• Set the baud rate 115200, data bits 8, parity bits none,stop bits one.
• Click on Open Serial button.

 

Results

• First you need to check if AT commands are working - enter “AT” and press  Send button.This would print "OK" which signifies of working connection and operation of the module.
• Requests TA revision identification. Enter "AT+GMR" and press Send button.
• For other AT commands see list here.