GM862 Cellular Module with BS2 Problems

dconvict

My Senior Design group needs to use the GM862 Cellular Quad Band Module (link below) and the GM862 Evaluation Board (link below) with Basic Stamp 2. We found a forum post (link below) that has a code and shows how to hook the GM862 to Basic Stamp. We have tried running the program with the set-up shown (picture attached) and have not been able to get it to work. Our goal is to send a text message. When we run the program, the debug terminal reads "Initializing system...", then "Autobauding...", than after about 4 seconds "No response: GM862", and finally "System down!" We have not been able to figure out where the problem is occurring. We are fairly new to Basic Stamp and have limited knowledge of circuits; however, we have had some assistance from professors on the circuitry. They feel that there may be a problem with the use of the transistor. We'd like to know if anyone could provide some insight into where we may be making a mistake.


GM862: http://www.sparkfun.com/products/757
Eval Board: http://www.sparkfun.com/products/277
Forum Code & Wiring Diagram: http://forum.sparkfun.com/viewtopic.php?f=13&t=13575

Mike Green

The author of the program (Joe Grand) does good work and knows his stuff. I would trust his program and design. How do you have things connected? Did you duplicate his level shifter? How are you powering the Module?