User manual
22.8.2018 Pmod ESP32 Reference Manual [Reference.Digilentinc]
https://reference.digilentinc.com/reference/pmod/pmodesp32/reference-manual 6/8
Carriage return and line feed bytes are omitted for clarity.
Command Behavior Example Response
AT Verifies that the device is in AT
mode and working
AT OK
AT+RST Resets the device AT+RST OK
AT+GMR Checks version info AT+GMR <At Version Info>, <SDK version
info>, <compile time>
AT+CWMODE Sets the WiFi mode AT+CWMODE=<mode> OK
AT+CWMODE Gets the WiFi mode AT+CWMODE? +CWMODE:<mode>
AT+CWJAP Connects to a WiFi access point AT+CWJAP=“some
network”,”some password“
OK or +CWJAP:<error>
AT+CWJAP Gets info about connected WiFi
access point
AT+CWJAP? +CWJAP:<ssid>,<bssid>,<channel>,
<rssi>
AT+CWLAP Displays information about
available networks
AT+CWLAP +CWLAP:<ecn>,<ssid>,<rssi>,
<mac>,<channel>
The Pmod ESP32 features an Xtensa dual-core 32-bit LX5 microprocessor. The Pmod is delivered to customers with the AT Instruction
firmware pre-loaded onto it. However, the user can write custom applications for the ESP32, flash them to the Pmod, and operate the
device outside of slave mode.
Some reasons to use custom firmware rather than the AT firmware might be:
The user would like functionality and behavior that are not limited by the UART baud rate
The user would like to make use of the SPI peripheral
The user would like to make use of the programmable GPIOs and LED ()
The user wishes to use the SDK provided by Espressif rather than the AT command set
The user wishes to use components on the ESP32 such as PWM, ADC (), DMA, I2C, DAC (), etc
The SDK provided by Espressif contains all of the functionality of the AT command set in slave mode, but with much more control of
timing and operation, and with additional control of peripherals that are not accessible in slave mode.
In order to write custom applications for the Pmod, a couple of tools are needed:
The Xtensa Toolchain
The Espressif ESP-IDF
Python
A USB-UART bridge device such as the Pmod USB UART (https://reference.digilentinc.com/reference/pmod/pmodusbuart/start)
To get started with setting up the tools for building projects for the Pmod ESP32, please reference Espressif's getting started guide
(http://esp-idf.readthedocs.io/en/latest/get-started/index.html).
When connecting to the Pmod to flash a custom application to it, utilize the UART port on top of the Pmod (Pmod header J2), rather
than the UART interface on Pmod header J1. Additionally, when flashing to the device, ensure that the device has been reset with SW1.2
in the “on” position before attempting to send the application to the ESP32. The quickest way to reset the device is to press the BTN1
located on the Pmod. In pressing BTN1, a hardware reset will occur.
A Pmod ESP32 with the out-of-box AT firmware
A serial terminal program such as minicom, screen, CoolTerm, or Putty
A UART controller for interfacing with the Pmod. This UART controller can be anything like a Digilent FPGA board with a
UART controller instantiated in the FPGA, or a Raspberry Pi or BeagleBone Black.
The UART Controller TX line connected to pin 2
Standalone Mode
Quick Start
Prerequisites