David Duffy (AVD) wrote:
> M. Adam Davis wrote:
>   
>> Given that it has an RTC, I'd suggest having the device "listen" for
>> only a few seconds every 10-30 minutes.  Once communication is
>> established, it could stay on until the control session is complete,
>> but it would save significant power if your client doesn't mind
>> waiting for an open control period.  Similar savings could be
>> established for the GSM cellular link.
>>   
>>     
>
> The remote control really needs to work 24/7 as there's no advance 
> warning of the when it might be called upon.
>
> As per my other post, I think a (custom) RF remote is the way to go.
> David...
>   
hard to beat the low cost, low power, (3V @2mA) and simplicity of the 
1200bps data rate / 2400Hz manchester encoded 315/433/868/915MHz ASK/OOK 
receiver (according to country) and simple SW. The receiver chips have a 
power down. You could maybe cycle on/off at 10% duty cycle every few 
seconds if 6mW is too much RX consumption.  30m is no problem with 1mW TX.

My last SMS project I used a dumb Nokia GSM phone, Serial cable and free 
Nokia SMS libraries translated to VB6 and converted to Run as NT service 
on NT4.0. Any of the $50 to $100 GSM modules will take a regular PAYG 
SIM or bill pay sim and do SMS via TTL serial.

 
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