
============= LICENSE INFORMATION ============================

This design may be used and modified for both commercial
and non-commercial purposes. You agree to hold the author
harmless for any damages you incur (direct or otherwise)
from use of this design.

There may be local laws regarding transmission of RF signals
with which you must comply with. It is your responsibility to
determine what regulations exist in your area and to
make sure that you are in compliance with those regulations.

The author of this design will not be responsible for 
any legal issues you may encounter (civil or criminal) resulting
from use of this design.

================================================================

 Here is the stuff needed to make a simple THGR810 clone.
==========================================================

Just about any PIC or AVR will work, I just happened to 
have lots of 16F88s and 12F675 so I used those. 

The tempearture/humidity sensor is a DHT-22, which 
is also known by the number RHT-03. This is available from
SparkFun and many other vendors. 

For the transmitter, you can use a SparkFun WRL-10534
or just about any 433.92MHz transmitter module that 
accepts a single wire data input. The pin numbers shown
on the schematic will work with the WRL-10534 transmitter,
but you may need to change them if a different transmit
module is used.

The software is written in BASIC. I used Oshensoft Basic, 
but its pretty standard, so any Basic Compiler should work 
with out much needing to be changed.

If you don't need to change the software, then the HEX files 
can be burnt into the suitable pics and will work straight away.
When burning the 12F675, make sure your burner enables 
the WDT fuse, otherwise the WDT won't run.

The one thing that you might want to change is the sensor's
channel number. To keep things as simple as possible, it is 
hard coded into the program. Search in the BASIC program
for the string "channel =" and then change the setting 
to whatever you want (anywhere from 1 to 10). Actually, with
the WxShield, you might be able to go higher -- all the way
to 15, but the WMR100 will not recognize that.

Current draw is approx 50uA, and most of this is the DHT22.
Battery life should be at least a year.

The software included in this package does not send a valid CRC
in the RF message, so OS consoles will not recognize the transmissions.
I'm working on getting the CRC problem fixed and will provide an
update when that is available. Then, the unit should be recognized
by OS base consoles like the WMR100 and WMR200.

The Arduino Weathershield receiver will recognize these transmissions.
If the CRC output feature is enabled in the Weathershield software,
then the WSDL program will not accept these signals, so be sure to
disable the CRC output feature.

I went down the Arduino Weathershield route, because my WMR100 is 
a bit buggy with its USB port, and sometimes stops sending data.
Its also pretty hopeless in receiving, mainly due to the hopeless 
antennas inside. 

Feel free to change / alter anything you like.

ZIP file contents:
===========================================================
1. Source code and hex files for the PIC12F675 processor
2. Source code and hex files for the PIC16F88 processor
3. Shematics for both processors
4. Photos of two sensors built using these processors
5. Datasheets for the DHT-22 sensor and 434MHz transmitter
6. This readme file


File Suffix Decoder:
================================================================
.bmp	Bitmap images of schematics for two different processors
.asm	Assembly language file produced by the BASIC compiler
.bas	BASIC language source file
.lst	Assembler listing output
.hex	Pre-compiled binary program file can be burned into PIC


