Serial Multiplexer Options

Hardware
#1

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!

#2

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.

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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.

#3

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.

#4

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

#5

:+1:

#6

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

#7

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

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