Post by thread:[PIC:] Anybody using Siemens MC35 and PIC ?

Mostly working OK but having an inconsistency problem. I'm using AT+CMGL to read the engine but don't always get a properly formatted response back. What I was expecting to receive is truncated and the rest padded out witth what looks like garbage If anyone has experience setting these up for SMS in text mode and have them working properly I'd like to hear from them TIA ============================================== Research is what I'm doing when I don't know what I'm doing - Wernher von Braun -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads

> what is the exact command that you are sending to MC35? The sequence I'm using is at http://home.clear.net.nz/pages/joecolquitt/mc35.html > You are working in Text or PDU mode? Text The problem is that there isn't always a concluding OK coming from the MC35. The diagram at the above address shows the OK included on the top memory dump, and OK missing in the memory dump below that. And it appears the MC35 just sends garbage instead of terminating the message properly as it does in the top example Everything else I've tried seeems to be working OK (sending SMS from the MC35 to a cellphone or e-mail address for example). Part of the problem is that there are so many parameters for commands in the AT Manual and I'm fairly ignorant of what they all do. The lack of examples and very technicalese descriptions don't help. It's been on hold for a few days and I did plan to look up a user group The problem with CMGL hasn't manifested itself (yet) using Hyper- terminal and the same set-up commands, which is puzzling. Electrically the PIC+MAX232 and the PC are quite close. I've looked at the data stream with an oscilloscope and logic analyser but can'[t detect any kind of breakdown. The MC35 itself seems to be the source of the bad data If you can see anything wrong or missing I'd be grateful for any advice thanks -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads

Any joy from Siemens NZ? I can send you contact details off list. They are supposed to have very good tech support (they say so) and at least should be able to send your well defined problem to someone who really knows. -- Brent Brown, Electronic Design Solutions 16 English Street, Hamilton, New Zealand Ph/fax: +64 7 849 0069 Mobile/txt: 025 334 069 eMail: spam_OUTbrent.brownTakeThisOuTclear.net.nz -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads

Hi, If it is working ok in hyperterminal then I would suggest you have a problem in the PIC. I don't know how you are doing the rs232 receive routine but would start looking there. I suspect you are missing characters. A good idea is to set aside a RAM buffer to use for rs232 rx and all the rs232 rx interrupt does it put the character in it. Then in a main loop keep checking the last character in for a delimiter ie in this case should be a carriage return, then process the info in the buffer. Hope that is of some help. Cheers, Peter Mcalpine {Original Message removed}

> If it is working ok in hyperterminal then I would suggest you > have a problem in the PIC. I don't know how you are doing > the rs232 receive routine but would start looking there. I > suspect you are missing characters. Well, I've scoped it and analysed it many times. Characters are not lost in transit, they just aren't being sent. It'll work maybe 3 or 4 times, then the next run, with a seemingly identical set-up, it doesn't work > A good idea is to set aside a RAM buffer to use for rs232 rx > and all the rs232 rx interrupt does it put the character in it. That's what is already being done (note - where the memory dumps come from), and actually how the complete project has to work anyway > Then in a main loop keep checking the last character in for > a delimiter ie in this case should be a carriage return, then > process the info in the buffer. If you look at the memory dump, you'll see it's full of CR and LF, which are not delimiters. The "OK" is the delimiter, and that's what goes missing -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics

An update on my problems back in March. We eventually gave up on the MC35 cellular engine. More bugs than a Mack's windscreen. Many emails bewteen Siemens offices all over the place accomplished nothing. Then we changed to the much cheaper Fargo Maestro 20 GSM/GPRS Modem and haven't looked back. It works perfectly with exactly the same commands that the MC35 choked on, and hasn't missed a beat in 3 months of intensive prototyping. So, a wee plug for Fargo -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics

> ... We eventually gave up on the MC35 cellular engine ... > Then we changed to the much cheaper Fargo Maestro 20 > GSM/GPRS Modem and haven't > looked back. It works perfectly with exactly the same commands > that the MC35 choked on, and hasn't missed a beat in 3 months I hope you have, politely, conveyed this latest information to Siemens. RM -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics

> I hope you have, politely, conveyed this latest information to Siemens. I expressed to Siemens, politely, promise, my frustration with the MC35. It had been pointed out to me, belatedly, that their range had a number of errors that migrated though the series. Some were fixed, some new ones appeared. Akin to Microchip's dodgy silicon episodes. What really stopped me enjoying the work was the uncertainty of when the next "anomoly" would appear and how to work around it. It's hard enough debugging a lot of code without having to factor in that the firmware might be at fault My client was less than happy, and I left it to him to confront his supplier. Although he is pleased with current progress, even though there's some furious catching up to do -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics