How to use 3 serial ports at a time?

[kyu]

Hi All,

I have a project that need to talk with BLE, GPS and a control device and all of them use Serial communication.
I was able to use Serial on TX/RX, Serial4 on C2/C3. However I still need another one to talk with.
I tried to use Serial2 but I found it need RGB led being removed.
ParticleSoftSerial I found from here GitHub - ScruffR/ParticleSoftSerial: This library provides a basic implementation of an interrupt timer driven software serial port on any two digital GPIOs as RX/TX. seems not working either.

And I found this article.

Adding a serial port using the SC16IS740

I added a library, SC16IS740RK, that makes it possible to use up to 4 SC16IS740 I2C UARTs off the I2C bus (D0 and D1). The chips support from 50 to 115200 baud and can go higher with different oscillators. Basically, just create the object and call begin() and it works like a regular UART like Serial1: #include "SC16IS740RK.h" // Pick a debug level from one of these two: SerialLogHandler logHandler; // SerialLogHandler logHandler(LOG_LEVEL_TRACE); SC16IS740 extSerial(Wire, 0); char out = ' …

Do you think adding a dedicated chip is only solution at this time? What else I can try?
Thanks,

[ScruffR]

@kyu

I tried to use Serial2 but I found it need RGB led being removed.

Have you tried the other interfaces mentioned in the docs?
https://docs.particle.io/reference/device-os/firmware/electron/#serial

@kyu

ParticleSoftSerial I found from here GitHub - ScruffR/ParticleSoftSerial: This library provides a basic implementation of an interrupt timer driven software serial port on any two digital GPIOs as RX/TX. seems not working either.

On what pins did you use it with what baudrate?

[kyu]

Hi @ScruffR,
Oh I didn’t know Serial5 is available on C1, C0 pins.
I just tested it and it works!
Thank you for your advice.

Kyu