Choosing the right board

[Searme]

Hello!

I am very new to ESP's hardwares and stumbled across them while working on my project. I want to be able to monitor a distant solar panel using a cheap diy method. So i had to choose a microcontroller to do the work for me! Here is my obstacle:
I need the board to be able to communicate its data using GPRS because no wifi will be available on the installation, and of course needs to be able to communicate with RS485 protocol for the inverters. I found this board and wanted to check if you think this is legit?

https://makeradvisor.com/tools/ttgo-t-c ... 32-sim800/

It is using a SIM800L module, apparently, and i need this to complete this project. Do you find this board legit? Is there any ESP board that is more interesting for my project?
Finally, will these devices suffice to calculate and send data to me remotely?

Thanks in advance!

[ESP_Minatel]

Hi,

I've never tried this board before. To use modem on ESP32 (GPRS/2G...) you will need this:

https://github.com/espressif/esp-idf/tr ... pos_client

[Searme]

Hey thanks for the reply!

Do you think an ESP32 board can handle both a RS485 communication and GPRS communication? Both use a UART IO i think.

[ESP_Minatel]

Hi,

Yes, with no problem! The ESP32 has 3 UART's (including the UART used for programming/debug).

[Searme]

Hey, thanks again for your help!

I have some last questions, I know that ESP's are 3.3V tolerant and with the addition of a RS485 module, I can't seem to find how i can check the voltage range of my RS485 communications. It is not written in any inverter datasheet (the system i am communicating with). I didn't find any sources talking about voltage protection on RS485 modules and ESP32. how can i be sure it's safe?

And finally, do you think an ESP can handle the storage of multiple measures, multiple times a day and send them?

Thanks!

[ESP_Minatel]

Hi,

You need to consider two things. First is the transceiver power supply that could vary depending of the partnumber and second the differential pair voltage (A and B). You need to see the datasheet of your transceiver to get the correct information.

You need to choose a part that supports 3V3 on the VCC supply, so that you won't have problems on the ESP32.

For the data storage, you can use part of your available flash memory to store data as you wish (See NVS, SPIFFS and FAT).