Flash & Sending AT Firmware on Adafruit Huzzah32 - esp32-wroom-32e

[mcuStudent001]

Flash & Sending AT Firmware on Adafruit Huzzah32 - esp32-wroom-32e
==============================

Context
===========
Use the Adafruit HUZZAH32 - ESP32 Feather as a wifi module. The main MCU is the 8051 ( AT89C51RD2 ) and the Huzzah32 is the board that provides wifi connectivity to the 8051. The 8051 has code that will send AT commands to the Huzzah32, such as AT+GMR, AT+CWJAP= , AT+CIPSTART= , and etc.

First, I need to download the AT firmware and flash it onto the Huzzah32. I used --> https://docs.espressif.com/projects/esp ... guide.html


I got the firmware and extracted it -> https://docs.espressif.com/projects/esp ... aries.html

Next, I set up the hardware connections to follow the diagram for ESP32-WROOM-32 Series -> https://docs.espressif.com/projects/esp ... ction.html
1. see "Connection of Components for ESP-AT Testing"
2. see "ESP32-WROOM-32 Series Hardware Connection"


Flash Of AT Firmware Works
====================
After I flashed the AT firmware, I pressed the reset button on the Huzzah32 board and then opened up a serial terminal on Putty ( Com 7, 115200 ). I got the following

rst:0x1 (POWERON_RESET),boot:0x13 (SPI_FAST_FLASH_BOOT)
configsip: 0, SPIWP:0xee
clk_drv:0x00,q_drv:0x00,d_drv:0x00,cs0_drv:0x00,hd_drv:0x00,wp_drv:0x00
mode:DIO, clock div:1
load:0x3fff0030,len:1184
load:0x40078000,len:13260
load:0x40080400,len:3028
entry 0x400805e4
ESP32 Feather!
MACADDR F0:24:F9:E8:4B:C1
scan start

So, the AT firmware is runnin and it does scan for available APs. The serial terminal does print out all of the available networks. Every 2~3 seconds, it will scan and print the available networks onto the serial terminal of Com 7.




UART1 for AT command/response Does Not Work
============================
Next, I tried to check the version of the firmware. Refer to the first diagram named "Connection of Components for ESP-AT Testing" on https://docs.espressif.com/projects/esp ... ction.html
1. Refer to the connection for "AT command / response".

I purchased the following cable to serve as the USB to serial converter ( https://www.amazon.com/dp/B083HVM7VZ?re ... asin_title ). The Huzzah has GPIO 16 as RX and GPIO 17 as Tx, which I connected to the USB to serial converter.



Sanity Check Did Not Work
===========================
The AT command / response is a separate UART ( UART1 ) on the Huzzah32 and the Com port is 8. I opened up a serial terminal in Putty, Com 8, 115200. Next, I tried to type in AT+GMR but nothing shows up on the terminal. I hooked up scope probes to GPIO RX and TX. Everytime I type a character, I can see that there is data being sent on the oscope. However, nothing shows up in the terminal. T

he document ( https://docs.espressif.com/projects/esp ... e.html#id4 ) has a section "Check Whether AT Works" that says typing in "AT+GMR" to the serial terminal will give a response of

AT version:3.2.0.0(s-ec2dec2 - ESP32 - Jul 28 2023 07:05:28)
SDK version:v5.0.2-376-g24b9d38a24-dirty
compile time(6118fc22):Jul 28 2023 09:47:28
Bin version:v3.2.0.0(WROOM-32)

OK


However, nothing shows up on the serial terminal of Putty. When I type, no characters show up on the terminal even though the scope shows that a byte is being sent. I can see that the AT firmware is working because the Huzzah32 is scanning and printing the available networks on the UART0, Com port 7.

However, UART 1, Com port 8 for AT command / response doesn't show anything.

Please advise on how I can get this to work.


Interface Goal
====================
Once I confirm that the AT command / response works, I'll lower the UART baud rate to 9600. Then, I'll interface the 8051 ( AT89C51RD2 ) with the Huzzah32. The 8051 will send Wifi and TCP AT commands to the Huzzah32, and this will allow the 8051 to connect to the internet via my router.

Please advise on how to get the AT command/response working for the Adafruit Huzzah32 - esp32-wroom-32e

[MicroController]

Make sure you connected the UART pins correctly (TXD to RXD, RXD to TXD). If you're 100% certain you have that right, swap TXD and RXD and try again.

[mcuStudent001]

Hi thanks for you reply.

I looked around and saw this resource about configuring the UART1 for At command/response ( https://docs.espressif.com/projects/esp ... odify-uart ). I did try all of the steps and reflashed the updated binary.

I also tried ESP32 Tx -> USB-UART Rx, ESP32 Rx -> USB-UART Tx but still not working.

Then I switched it ESP32 Tx -> USB-UART Tx, ESP32 Rx -> USB-UART Rx but no luck.

The UART0 for debug and monitor still shows that the Huzzah32 is scanning for access points and it still prints them out every 3 seconds. I'll keep looking around and see what else I can do.