Hello I'm trying to build a GPS locator device with arduino and A7 aithinker GSM/GPS/GPRS module.
I would like to make the arduino sleep to save some power . Is it possible to wake it up through sms ?
If the receiver of the SMS has to remain powered, to receive the SMS, is there much to be gained by putting the unknown Arduino to sleep and saving a few mA ?
I believe the gsm module can be put to sleep as well and wake up via sms .
I'm not sure if that works on my specific module though.
on other module like sim900 there is even an at command to put it to sleep mode and wake it via sms or the at command.
but i would like to know if i can do the same with the arduino.
themtsil:
I believe the gsm module can be put to sleep as well and wake up via sms .
Fair enough but how exactly does the SMS module receive anything if its asleep, as in turned off ?
I'm not sure if that works on my specific module though.
Might be worthwhile checking ........
The pic I attached bellow is for sim900.
It doesnt work on my module but it has a pin called sleep .
anyway in that pic it sais that after enabling sleep mode the module can be activated via sms or call .
themtsil:
The pic I attached bellow is for sim900.
It doesnt work on my module but it has a pin called sleep .
anyway in that pic it sais that after enabling sleep mode the module can be activated via sms or call .
Oh, I see.
Does the sleep pin work ?
How much does it reduce the SIM900 current consumption by ?
Unfortunately i haven't tried to wake arduino via sms however i can confirm by putting a sim800l gsm to sleep in code using "AT+CSCLK=2" and not with the pin mine drops from around 21-22ma to 1.5-2ma and still wakes on receipt of a sms or call so its well worth it if that helps.
In the item description sais for sleep pin that high level enters in low consumption and low lever quits low consumption.
Saddly I can't measure how much mA has in both modes.
I ordered a multimeter to find out.
But even if I can't measure anything when I command sleep pin to "high" the module works fine .
So how is it possible to work perfectly fine but have lower consumption?
Thank you for your support guys.
I'm still very new to GSM modules but i found that they both had the same consumption but it was much easier to declare the sleep in setup then never have to worry about setting pins high or low as it wakes itself automatically on receipt of an SMS or call.
The only extra thing you have to do is send an AT command to wake it on the serial before you want it to do something with a real command so send it a random command which it will ignore but wake then straight after send the command you want it to perform but personally i found that easier than keeping track of the pin state plus it can free up a pin.
P.S
I also use mine with a 10F super cap which allows me to measure a nice stable overall use current as the module is all over the place current wise up to 1.9amps! when working and also allows me to use a very small battery if i pre-charge the cap first.
I have opened several commercial electricity meter GSM monitor modules and found they use the same method of a super cap to power the bursts while only being powered from a 100-250ma supply from the original meter board.