The Canberra THGR810 Clone

Open Source Hardware Engineering

THGR810 Clone built using a Microchip PIC12F675 micro-controller

This design was contributed from someone in Australia. There are two versions here. it has been discovered that the OS consoles require extremely accurate timing of both RF pulse widths and spacings as well as the time interval between transmissions. The second version meets those requirements, although the author does report a few infrequent dropouts with the version 2 design.

• The first version is a working THGR810 clone...with one caveat. It DOES work if your receiver is one of the WxShield units (described elsewhere on this website). The only problem is that it does not use correct RF pulse and transmission timings, nor does it send the correct cyclic redundancy check (or "CRC") code at the end of the message, so Oregon Scientific base consoles do not recognize the transmissions.
• The second version is a fully working THGR810 clone. It produces the correct RF pulse timings and proper time spacing between transmissions. It has been tested with WMR80 amd WMR100 OS consoles so far.

Which version should you build?

• If you are using a WxShield receiver, version 1 of this project will work.
• If you use an OS base console, you must use the version 2 design. Be sure to grab version 2.1 because it includes a firmware bug fix.

Click here to download a zip file containing a license, instructions, schematics, data sheets, photos, and software for version 1 of this project.

Click here to download a zip file containing a license, notes, timing information, schematics, and software for version 2.1 of this project. We no longer provide a link to version 2 because that zip file contained a firmware bug.