UART or Manchester?

[Vizier87]

Hi guys,
I custom built a UBW, and wondering whether I should wire my 315 Mhz RF modules (both on Rx and Tx) directly for direct UART communications or should I use RS232 chips to utilize Manchester modulation? Which would be better?

 

[DirtyLude]

Depending on the modules and I'm assuming these are dumb radio modules then you use some type of balanced encoding, it doesn't have to be Manchester, but it can be.

You do not use the UART and you do not use RS232 level shifting IC's.

 

[Vizier87]

You do not use the UART and you do not use RS232 level shifting IC's.

Hi Mark,
According to this:
SparkFun Electronics - RF Link 2400bps Receiver - 315MHz
It says:

What the transmitter 'sees' on its data pin is what the receiver outputs on its data pin. If you can configure the UART module on a PIC, you have an instant wireless data connection.

So what encoding should I use? Is Manchester coding possible via directly wired Rx-Tx modules to the PIC's Rx & Tx?

 

[Wp100]

Hi,

The SparkFun boards connect directly to your pic.

You will soon realise you need to use the Manchester coding as your receiver will be flooded with all the signals from all around your area.

I used Nigels Manchester coding from his tutorial site - works well on my 18F chips.

 

[DirtyLude]

Hi Mark,
According to this:
SparkFun Electronics - RF Link 2400bps Receiver - 315MHz
It says:...
So what encoding should I use? Is Manchester coding possible via directly wired Rx-Tx modules to the PIC's Rx & Tx?

Those modules don't like the UART for multiple reasons. 1. UART control signals are backwards, carrier is always on; 2. UART signals are edge triggered; 3. UART signals cannot be fully balanced even with encoding, due to the carrier and control bits.

This has all been recently talked about here:
https://www.electro-tech-online.com/threads/wireless-project.104454/

 

[Vizier87]

Okay.. I'll look into it.