Adding Wifi to Existing Product

[embedded_guy]

Hi,

We are looking to add wifi capabilities with the ESP32 (ESP32-MINI-1) to our existing product which runs STM32 + FreeRTOS + lwip + webserver over ethernet. Currently the product is accessed over ethernet for udp control commands, web server, and code updates. We are hoping to use the ESP32 as a quick, drop-in, extension, standalone module that provides a wifi "tunnel" to pass data/commands (as listed previously) so that the main processor can process the incoming requests.

I'm trying to understand the best way to go about doing this. It's not clear if we need to use the AT command set or if there are other options for this type of application use of the ESP32. I see there are AT binaries, but not sure which one is for the MINI-1.
If you can point me in the right direction, to an example on how to go about doing this, we appreciate it.

Thanks

[ESP_Sprite]

If you already have lwip running on the host, you may want to take a look at ESP-Hosted which would allow you to effectively add the ESP to the STM32 LWIP stack like another network card.

[embedded_guy]

Thanks for the response.

Looking at the ESP-Hosted mode it seems that needs SPI to interface to the ESP32(-MINI, in my case). Not sure I'll have that module resource available. Might only have a uart, which could force me into AT command mode.

I'm not sure if (or how at this point) packets are received into the ESP32 and forwarded on to the Host MCU. Especially for a code update, that will require a lot of incoming packets.

Also, it isn't clear if lwip allowed multiple network interfaces.

Thanks,
Anthony

[embedded_guy]

Hi,

I am planning on using the ESP32 in AT command mode since we do not have enough hardware interface modules (SPI, etc.) to support any other modes such as ESP-hosted that was previously suggested. (I think I can try hosted on a future next-gen product).

I have the ESP32-DevKitM-1 but I do not see a binary image I can use for that for the -MINI. Do I use the ESP32-WROOM image?

I'm also not sure where the flash download instructions are for this DevKitM. When I plug it in I see the following output

rst:0x10 (RTCWDT_RTC_RESET),boot:0x13 (SPI_FAST_FLASH_BOOT)
invalid header: 0xffffffff
invalid header: 0xffffffff
invalid header: 0xffffffff
invalid header: 0xffffffff
invalid header: 0xffffffff
invalid header: 0xffffffff
invalid header: 0xffffffff
ets Jul 29 2019 12:21:46

If I press the boot button, I get this message

rst:0x10 (RTCWDT_RTC_RESET),boot:0x3 (DOWNLOAD_BOOT(UART0/UART1/SDIO_REI_REO_V2))
waiting for download

I also have DevKitC-v4 boards.

Any help is appreciated.

Thanks.