<html xmlns:v="urn:schemas-microsoft-com:vml" xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:w="urn:schemas-microsoft-com:office:word" xmlns:m="http://schemas.microsoft.com/office/2004/12/omml" xmlns="http://www.w3.org/TR/REC-html40"><head><meta http-equiv=Content-Type content="text/html; charset=us-ascii"><meta name=Generator content="Microsoft Word 14 (filtered medium)"><style><!--
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</o:shapelayout></xml><![endif]--></head><body lang=EN-US link=blue vlink=purple><div class=WordSection1><p class=MsoNormal><span style='font-family:"Times New Roman","serif"'>Hi,<o:p></o:p></span></p><p class=MsoNormal><span style='font-family:"Times New Roman","serif"'> I was talking with Dan a few weeks ago about sending the GPS coordinates from an Arduino microprocessor and getting the results to display on the map. He also recommended that I post on this mailing list to discuss the solution. I now also need the capability to send text to the IM interface of D-RATS. I’ve been able to output a message sent from D-RATS into HyperTerminal and what I concluded from that is that there is some type of message ID and checksum value that needs to be calculated upon transmission of the message and a check on the receiving end of the message. I’m working on a homing system for firefighters that sends the GPS results to the map screen and sensor data to the IM screen. Could someone fill me in on how this checksum works? Thanks for your help.<o:p></o:p></span></p><p class=MsoNormal><span style='font-family:"Times New Roman","serif"'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-family:"Times New Roman","serif"'>-Timothy Le<o:p></o:p></span></p><p class=MsoNormal><span style='font-family:"Times New Roman","serif"'> Sierra Canyon School<o:p></o:p></span></p><p class=MsoNormal><o:p> </o:p></p></div></body></html>