Suspicious of Radiohead library - need help in troubleshooting

Projects Networking, Protocols, and Devices
1

Hello

I am trying to get 433 MHz RF modules working - unsuccessfully. The purpose of this post is to understand if there is a way to confirm beyond a doubt that the Radiohead RF library in itself is functioning correctly. Here are the details.

These are the ones specifically; Nicerf SRX882 and STX882.

I am using two Arduinos (1 Uno, 1 Duemilanove), Atmega328P processors. The Radiohead library is version 1.98

Here is how they are hooked up: on the left is the transmitter, with txpin 7, and on the right is the receiver with rxpin 6. See attachment for a picture.

I'm using Radiohead code examples found here. I've tried the code there as is - several tries. Then I changed the tx and rx pins in the driver constructor - several tries there as well.

I see no data on the receiving end. Wishing to eliminate the library as being the problem, I connected "in duplex" as described mid way in the RH_ASK documentation. A connection is described there for 'testing purposes'.

For testing purposes you can connect 2 Arduino RH_ASK instances directly, by connecting pin 12 of one to 11 of the other and vice versa, like this for a duplex connection:

Arduino 1 wires Arduino 1
D11-----------------------------D12
D12-----------------------------D11
GND-----------------------------GND

So I have removed the STX & SRX hardware, and simply cross connected pins 6 and 7 of the two Arduinos.

Appologies for the long preamble!

My questions:

  • Am I doing this correctly to find out if data is being sent out on txpin 7?
  • If data is received on rxpin 6, will the library on the receiving end actually 'see it' hooked up in this fasion?
  • Please let me know if this test connection setup should be used differently than I describe here.

Oh, I do have access to an oscilloscope - but very much a noob at it. Do let me know if or how it could be used to check for data on the txpin!

Any other pointers will be appreciated for sure!

Ron,
Montreal

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2

OP's image.

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Test with wires instead of radios, as described in the library docs. Don't forget to connect the grounds.

It is usually best to try the example code that comes with the library, rather than a random web site. However, I recommend the VirtualWire library, as it is simpler and much smaller.

3

presse55:
Any other pointers will be appreciated for sure!

You need to connect a power supply, for both TX and RX sides.

4

Thank you for the replies and reposting my pic!

In the wire-to-wire test (where I did remove the SRX & STX) I had both arduinos powered, and with a common ground. The receiving arduino did not output anything - dead silence.

I will try the sketches from the Radiohead library web site.

And if that fails, I'll give the VirtualWire library a shot.

Thanks!!

5

Well I finally do have a working STX and SRX.

In troubleshooting I found out I had a bad arduino (pin 12 never went to 5VDC!!), and I had a bad breadboard jumper wire. Threw them both out!

The Radiohead library never worked either. I tried the current version 1.98, and one from January 2018 1.82 without luck.

The VirtualWire library works find though.

Ciao from Montreal

Ron