Looking for "transparent" RF transceiver

[flotulopex]

Hello,

Like other projects on this forum, I'm looking for RF transceiver modules that are "transparent".

In my project, I will send very small data packets (20-30 bytes) once a day (data logger polling).

As I'm not an RF module engineer, by "transparent" I mean a RF module to which I can connect a µC sending serial data and vice-versa on the receiver's side.

I have found lots of different modules on the net but I'm not so sure which one I should go for and some of the ones I could have chosen are not "allowed" where I live in Switzerland, Europe.

As an example, here is a transceiver from AUREL that could fit (well I suppose it should) my needs: AUREL RTX 868 FSK (650201343G) (http://www.aurelwireless.com/radiomodem-rf-data-transceivers/). Unfortunately, it is not available for hobbyists :-(
http://www.aurelwireless.com/wp-content/uploads/2011/03/RTX-868-FSK.jpg
What looks great with this module is:
- it has a PCB antenna ("on board");
- data is transmitted in a "transparent" way;
- it's interface is serial (most simple to me).

Now I have found this module from LINX TECHNOLOGIES HUM-868-DT, the 868MHz HumDT™ Series Transceiver (https://www.linxtechnologies.com/en/products/modules/humdt-frequency-agile-rf-transceiver). But I'm not sure if it does the same as the AUREL one and I also need to add an antenna (not that tragic).
https://www.linxtechnologies.com/bundles/linxarticle/linx/img/products/humdt.png
Can anyone tell me if I'm going the right way or what I should pay attention at?

[picster]

Probably cost factor (got a budget?) and transmission distance would play a role in providing suggestions?

[gadelhas]

I'll been using (hobby) the HC-12 modules available everywhere. They are cheap and work well.

For professional projects, i only use LORA devices

[Dick Ivers]

I also use LORA modules for most projects. They utilize a SPI interface to the microprocessor. Not sure this meets your definition of transparent but they work fine.

I have also used wireless modules from this source: https://www.wirelessthings.net/rf-module-range/serial-transcievers. These modules have a serial interface and are easy to use. You could definitely call them "transparent".

[flotulopex]

Thanks for the feedback.

I just had an offer from AUREL. They will sell me the transceiver I initially found being (hopefully) the best for my need.
http://www.aurelwireless.com/wp-content/uploads/2011/03/RTX-868-FSK.jpg
I'll have a try with this one.

[flotulopex]

I just want to take a few minutes to give a short feedback about the use of the AUREL RTX 868 FSK (650201343G) (http://www.aurelwireless.com/radiomodem-rf-data-transceivers/). I receive the ones from LINX too (see post #1) but I had to finish the project asap so I took the ones that arrived first ;-)
http://www.aurelwireless.com/wp-content/uploads/2011/03/RTX-868-FSK.jpg

Once I had set up my wired proto on the breadboards for 9600bps serial communication, I removed the three wires (RX/TX/GND) "implemented" the modules and...got into trouble.

8278

Before I powered-up the proto, I realized the RTX modules need 3.6V max :eek: and most of my project are made for 5V (silly habit, maybe).

So I started looking around the internet on how I would be able to shift voltage levels and found, ie,the BSS138 level converter (https://www.sparkfun.com/products/12009). But I also found in our forum some people asking why 5V projects would not simply be powered in 3.3V; that's true...why not?

Luckily all the components I use can be fed with 3.3V :p; so I adjusted the PICkit's voltage and...it worked like a charm.

Connections to the modules are very easy (Pwr, Enable, TX or RX and data) and, what I always like, the PCB's footprint has a pitch of 2,54mm.
8279

I tested the RF link over 180 meters across buildings without any problem.

Last but not least, the module proudly works with...?
8281

Actually, I paid $ 12,50 per module (came from POLAND).

Voilà

[Ioannis]

Congratulations Roger!

180 meters across buildings, at 868 @10mW is great!

Ioannis

[technotronix]

I have used this transceiver with the purpose of the ZigBee pairs, but not worked.