Sending an SMS Based on Capacity Project

[Hobnob]

Hi guys

I've been looking thru this forum and i think you're the guys to help me.......(congratulations)

I stupidly said i'd help my nephew with an electronics project at school forgetting i know nothing about electronics. I suggested he build the below without really understanding if it could be done. Can you experts tell me if it is possible and how would you go about building it ?

Objective:
I have a receptacle which over time will fill up. Rather than checking on it every day, i want an SMS to be sent to my mobile phone telling me it's 25% full, 50% full etc. Ideally it needs to be solar powered !

I'm guessing i'll need something like:
- An ultrasonic range finder to determine distance
- A programme to work out the % fill (based on a calibration of distance when empty)
- Some form of GSM data card (with signal) to facilitate the sending of the messages
- Programming to send the correct SMS
- A PCB with all the hardware & programming stored on it
- A solar panel powering the PCB / data card / sensor. If this is not possible due to power requirements, battery operated

I'm happy i could help with the programming being an ex Cobol & C programmer. It's the electronic stuff which i need to learn and i don't have a clue where we'd start.

Many thanks and i hope the above is not too stupid.

 

[(*steve*)]

What you probably need to find is an SMS gateway device.

If you decided to use an Arduino, this is the sort of thing you could use. Note that it will require its own SIM to operate so it will get its own telephone bill!

If you look at the description you'll notice that there is an option to only power this unit as required. That would be best in a solar/battery environment as there is no point in leaving it turned on while you're not using it.

Even if you go for solar power you will still require a battery to provide power during the night and on cloudy days. A relatively simple option is to use a 12V lead acid battery and a solar charger. As long as you can supply significantly more energy back into the battery each day (on average) than you draw (try to be able to get twice or more) then you should be OK. The battery capacity needs to be good enough to last through the night (obviously) but also perhaps for a couple of consecutive cloudy days.

There are cheap and easily used ultrasonic range finders, and these have libraries for the arduino.

With luck you can get most of it in pre-built modules and you won't have to design any hardware.

Beware that any device which connects to your phone network needs to be carefully tested to ensure that it doesn't run up a huge bill because it probably won't be able to pay it!