AXE 213 queries

[Ninja MacNinja]

Hello again guys I have some queries regarding the transmission of my code. I have my weather station now working and have tested all the results and they look good. I am now thinking about having the OLED screen inside as this will be more practical. I have the AXE 213 Radio board and the RFA001 and have managed to send and receive some data from the two units onto the OLED. Apart from some signal issues that I'm having the information is not being displayed in the correct order/lines. I am using the single wire method as I currently only have one micro-controller. I have attached the code I am using together with a picture of the message being displayed and of the receiver. Has anyone else encountered this issue and if so, how did you resolve this.

With regards to the signal issues, I am just using a piece of single core wire, which is not providing a consistent signal even with the boards in the same room. It seems to help if I prop up the unused send cable, which made me think there may be a short circuit. I tested and checked the board for anything like this, but it looks the same as the diagram. Is this a common issue. I turned off all the electrical equipment in the room but this did not resolve the issue.

Okay, just tried to upload the pictures, but it is not working. If you need them I'll work it out and post later.

Any input is would be appreciated.

Thanks


View attachment First transmit code.bas

 

[neiltechspec]

I assume you mean a twisted pair - Signal & Gnd

What 's the distance between the two ends ?.

You may have to consider RS485 if it's too far for serial TTL.

Neil.

ooops, just noticed the bit about Radio modules, so my questions are not relevant.

 

[inglewoodpete]

I have my weather station now working and have tested all the results and they look good. I am now thinking about having the OLED screen inside as this will be more practical. I have the AXE 213 Radio board and the RFA001 and have managed to send and receive some data from the two units onto the OLED. Apart from some signal issues that I'm having the information is not being displayed in the correct order/lines. I am using the single wire method as I currently only have one micro-controller.

I have two AXE 213 / RFA001 radio pairs and have had mixed results. One Rx/Tx pair works well, so I know that they can work ! The other pair only successfully transmits/receives data perhaps once every 100 packets. My problem is that I'm on the other side of the world to Rev-Ed and returning the faulty items costs more than they are worth. So my project has been shelved for the time being.

You need to read and understand the data sheets completely in order to get on top of the way the AXE 213 / RFA001 work. The way you have your code suggests that you have not understood that the radio protocol transmits packets of 8 bytes at a time. If you have less that 8 bytes, you must send 'padding' bytes to make up the eight. If you have more than 8 bytes to send, then you must use more packets while ensuring that the last packet is padded out to 8 bytes.

With regards to the signal issues, I am just using a piece of single core wire, which is not providing a consistent signal even with the boards in the same room.

I'm not sure what you're trying to say here. If you are referring to the Tx and Rx aerials please call them aerials. The aerials need to be within a millimetre or two of the EXACT length to work well. If you are referring to the connections between your weather station and AXE213 or AXE213 and AXE133 (LCD), then you need a 0v return leg connection too.

 

[Ninja MacNinja]

Yeah, I didn't even think about the OLED commands sending 8 bytes at a time. Ill need to look over my code again and make any changes. I was concentrating on other factors and overlooked that. May also need to amend the code for wind speed and temp as they may only be single figure digits and be less than 8 bytes.

Yeah I was talking about the aerials. I wasn't aware of the 0v return leg. I will look into this this evening once im out of class.

Thanks

 

[Ninja MacNinja]

Ok, so i've amended the code to ensure that any piece of information being transmitted is 8 bytes, although this won't be the case if the temperature or wind speed goes into double digits. I am not to sure how to sort this issue so will scroll through the PICAXE forum to see if I can find a solution.

I removed the aerials that I was using and carefully measured out new ones, which seems to have worked a treat. Hopefully after I get the code dorted my first project will be done

 

[inglewoodpete]

Sending a variable-length string as a fixed-length one can be done like this:

[color=Blue]Symbol [/color][color=Purple]bSpeed [/color][color=DarkCyan]= [/color][color=Purple]b10   [/color][color=Green]'Wind speed[/color]

[color=Blue]SerOut txpin[/color][color=Black], [/color][color=Blue]N2400[/color][color=Black], [/color][color=Blue]([/color][color=Red]"Speed:"[/color][color=Blue])  [/color][color=Green]'Start of packet[/color]
[color=Blue]If [/color][color=Purple]bSpeed [/color][color=DarkCyan]< [/color][color=Navy]10 [/color][color=Blue]Then
   SerOut txpin [/color][color=Black],[/color][color=Blue]N2400[/color][color=Black], [/color][color=Blue]([/color][color=Red]" "[/color][color=Blue])    [/color][color=Green]'Insert an extra space[/color]
[color=Blue]End If
SerOut txpin[/color][color=Black], [/color][color=Blue]N2400[/color][color=Black], [/color][color=Blue]([/color][color=Black]#[/color][color=Purple]bSpeed[/color][color=Blue])   [/color][color=Green]'End of packet[/color]

Note the your Count command for wind speed MUST use a word variable, even if the values are always less than 256. Refer to the command description.

 

[Ninja MacNinja]

Ok so I have now amended the count command and readtemp to include a word variable. The circuit seems work well and I'm chuffed with the results. Thanks very much for your help on this, it was greatly appreciated. All I need to do now is finalise the PCB design on Proteus, etch and solder, then house the parts.

Quick question, what have you used to house your outdoor unit/s. I was thinking of making a Stevenson screen, but I don't know if that's a bit over the top.