Using LPRS EasyRadio with Raspberry Pi – part 2

This part deals with the program that runs on the PC, any two or more devices can communicate, but the software provided by LPRS will only run on a PC. You should have downloaded and installed the EasyRadio Companion as detailed in part 1. Before running this software, and before plugging in a radio open up Control Panel, go to System Hardware and open up the COM port list. Make a note of the items listed then plug in a radio, Windows will install the necessary drivers. Once these have been installed the radio will show up as a USB serial port, make a note of the COM port number. Now run the EasyRadio companion

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You will need to set up several parameters as the program does not do this automatically. Click on Settings in the top menu bar, then click RS232 Settings. Click on the radio button alongside Device 1, in the drop down box alongside Port select your COM port number (the correct port is NOT selected automatically). For the moment leave Baud set at 19200, Data Bits at 8, Stop Bits at 1 and Handshaking at None as these match the values in the Python sketch on the Raspberry Pi. Click on Store, then Exit.

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Click on settings again, then Select Device, click on Device 1. Make sure UART Baud Rate is set to 19200 and click Update. Make sure Frequency Channel is set to C0 and click on Update.

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Click on the button marked Send Command and the Device I’d will be shown. Click on Read Module and the Serial Number and date of manufacture will be shown. Make sure the tab ERA Modules is highlighted and click on the Communication tab.

Fit a radio to a Raspberry Pi and start up the Pi. Once the desktop is displayed start Idle and load the Python script that you downloaded in part one of this post. run the script.

Type something at the cursor and press enter, this text will appear on the PC in the large box on the Communication Test page. Now type something in the box marked -enter your text here-.

Nothing will appear on the Raspberry http://wp.me/p4Suyg-7jPi as the Python script is waiting for a keyboard entry, however the text sent from the PC has been stored. Type something into the Python script followed by enter. The contents of the received buffer will now be printed.

That’s is it, two way communication has been achieved!

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2 thoughts on “Using LPRS EasyRadio with Raspberry Pi – part 2”

    1. My original plan was to use them to communicate with a tethered weather balloon that would rise to 1000 metres, but for a number of reasons I never got it further than 400 metres. The signal was strong at that distance and I have no doubt that it would have worked at 1000 metres. However, for my third and final attempt to reach 1000 metres this summer I have completely rebuilt the electronics. The LRPS units were very good, but at £100 for the pair they are expensive for what they do. It may be possible to pick them up cheaply as they seem to have been replaced by newer units. My communication module of choice now is the HC-12, operating at 433 MHZ. These can be purchased for around £12 for two. The maximum range quoted for these is about 1800 metres, but this at a much reduced data rate. I suspect that they could reach 1000 metres in free air. I am just finishing the initial testing of my new unit for the weather balloon and hope to figure out the range. I will post all the details in a blog soon. What kind of project were you thinking of using the LRPS for?

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