Serial Multiplexer Options

Hi there,

What options do I have for using two UART devices with a particle boron? I have found this repo with a custom board GitHub - rickkas7/SC16IS740RK: Interface to SC16IS740 UART for Particle devices that I can make with JLC or something. But, I’m wondering if there’s an off the shelf board I can make to use SPI/I2C as another serial port.

Thank you!

Welcome to the community.

What sort of serial comms do you need?
There are several hardware serial comms ports available on a Boron - Serial and Serial1 and then you can use other pins for soft serial.


SPI is a bus and the number of end node devices is limited by chip select pins
I2C is a bus and is limited by end node device addresses. Where you have 2 I2C devices with the same address then the SC16IS740 helps overcome this and similarly for SPI where Boron CS pins are in short supply.
Using a IC adaptor board it is possible to solder the IC and then use a breadboard to try it out.

I recommend the SC16IS7xx series if you need additional UART ports. There are a bunch of pre-made breakout boards if you search for SC16IS750 on Amazon, eBay or AliExpress. The library above works with most of the variations, not just the SC16IS740.

There is currently no soft serial library for Gen3 and Serial is only a virtual serial port (USB CDC).

:+1:

@armor @ScruffR @rickkas7 Gotcha - thank you all. This is very helpful.

This looks very interesting for a serial multiplexer, though no hardware handshaking.

1 Like