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Development => Other Hardware Development => Topic started by: Bjack795 on Nov 18, 2018, 12:19 pm

Title: UART2 - Hardware Serial 2 ports in Wemos D32 pro (ESP32 based)
Post by: Bjack795 on Nov 18, 2018, 12:19 pm
Hi all!

I want to make you a technical question.

I'm using this (https://wiki.wemos.cc/products:d32:d32_pro) board and in the past I needed to use the Hardware Serial 1 ports, and I succeded in finding them on the datasheet.

Now I need the UART2 ports but as you can see from the picture attached U2RXD is corresponding to PIN 13 on the board but U2TXD is corresponding to SD2, and I don't know how or whether I can access it.


This is from ESP32 Datasheet
(https://user-images.githubusercontent.com/42472256/48671606-4c3d3180-eb2b-11e8-8117-5da45ad9213d.jpg)

This is the corresponding D32 pro Schematics

(https://user-images.githubusercontent.com/42472256/48671604-48111400-eb2b-11e8-86ea-26d3bf3ce162.jpg)
Title: Re: UART2 - Hardware Serial 2 ports in Wemos D32 pro (ESP32 based)
Post by: Malakashka on Dec 11, 2018, 07:56 pm
I am currently using the board in question for the university project and I had a similar question to your's. We are using UART to get data from a GPS module. I've come to realize that while the chip has 3 UARTs, the board only provides connection to UART0 at the pins 3-RX and 1-TX. This is confirmed from the specification on the board at TinyTronics website (its a version 2 vs version 1, but still the same board).

The interesting part here is that UART0 being the only external UART on the board, also acts as a programming channel for the board. This means that you can't use it for project purposes and for printing serial messages at the same time.

Hope I was of help :)
Title: Re: UART2 - Hardware Serial 2 ports in Wemos D32 pro (ESP32 based)
Post by: Bjack795 on Dec 11, 2018, 10:42 pm
I am currently using the board in question for the university project and I had a similar question to your's. We are using UART to get data from a GPS module. I've come to realize that while the chip has 3 UARTs, the board only provides connection to UART0 at the pins 3-RX and 1-TX. This is confirmed from the specification on the board at TinyTronics website (its a version 2 vs version 1, but still the same board).

The interesting part here is that UART0 being the only external UART on the board, also acts as a programming channel for the board. This means that you can't use it for project purposes and for printing serial messages at the same time.

Hope I was of help :)
Thank you for the information.

I solved this problem when I discovered that quite every pin can be used for UART2 and UART3 in the "hardware serial" setup.