This sounds perfect for a backup control system. However, using mobile phone/gsm to control primary systems has the following problems.
1) Latency - texts can sometimes be late.I have known a delay of 24 hours during Christmas and new year peaks. 2) Spam texts - the phones inbox fill with offers for ringtones etc 3) Card top-ups. The procedure and validity of the top up card is controlled by the operator i.e. processes change without notification to the user... you go past the re-activation date and bingo..the only way forward is to get a new card and number. Having stated the above, it can be made to work -Regional Electricity Companies(REC) use Vodaphone to switch pole mounted 11kv vacuum interrupters. Personally at a repeater site I would use a contract phone on low band (900Mhz) with a good external antenna and a proven GSM controller. Matt- Thank you for publicising this article, most interesting. I will of course, be switching my soldering iron on and ordering the PCB/components following the next issue. Ian G8PWE Walsall UK ----- Original Message ----- From: "Matt Beasant" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]>; <[email protected]> Sent: Friday, March 02, 2007 9:00 PM Subject: [Repeater-Builder] Remote control via text message > Hi > > This months edition of Everyday Practical Electronics magazine features part > one of a project to build a device to enable remote control and remote > status indication all via an old Nokia mobile phone suing GSM based SMS > service ( text message ) > > See the magazine web site here: > > http://www.epemag.wimborne.co.uk/index.html > > This could sure be useful on remote repeater sites especially ones using > battery power or wind/solar power. > > The design includes battery management functions so as not to overcharge the > battery and in the event of a power outage and the phone switching off due > to low battery, upon restoration of power, the design switches the phone > back on again. > > Part two will be in the shops next week but copies should be available via > the web site's online shop. > > Matt > G4RKY. > Note, I have no connection with any of the parties involved in this project > in any way. > > > > ___________________________________________________________ > To help you stay safe and secure online, we've developed the all new Yahoo! Security Centre. http://uk.security.yahoo.com > > > > > > Yahoo! Groups Links > > > Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ <*> Your email settings: Individual Email | Traditional <*> To change settings online go to: http://groups.yahoo.com/group/Repeater-Builder/join (Yahoo! ID required) <*> To change settings via email: mailto:[EMAIL PROTECTED] mailto:[EMAIL PROTECTED] <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
