Send an SMS with a Picaxe

woschx

New Member
Hello,

is it possible to send a message to a mobile phone with a Picaxe?
In other words, is there a module to send SMS messages to a mobile phone?

greetings

Wolfgang
 

hippy

Technical Support
Staff member
[Moved to Active Forum]

There are GSM and GPRS modules which are able to send SMS messages.

There are quite a lot of "M590" based boards available these days at unbelievably low prices, below 2 GBP, EUR, USD as kits. No idea how well those work or on which networks but seem to have people saying they work via 3V3 serial. Some warn that the kits don't always use new parts, aren't 100%.

There are more expensive commercial units, which often have a 9-way D serial connection, which are usually good quality and well documented.

A cheap kit may be worth taking a gamble on. A similar ready built board bought through a reputable store should have more guarantee of it actually working and an exchange policy if not. For something mission critical like a theft alert one should probably consider something commercial with an established reputation for reliability.
 

inglewoodpete

Senior Member
There are GSM and GPRS modules which are able to send SMS messages.
Note that GSM and GPRS are old technologies and providers in many (most?) countries have either closed down these networks or are phasing them out. That is one of the reasons why the modules are so cheap. Check what is happening in your country before buying a GSM or GPRS module.
 

Jeremy Harris

Senior Member
Note that GSM and GPRS are old technologies and providers in many (most?) countries have either closed down these networks or are phasing them out. That is one of the reasons why the modules are so cheap. Check what is happening in your country before buying a GSM or GPRS module.
Good point, and one I checked on recently. There seem to be a large number of legacy systems here still using the 2G network in the UK, (over 50% of voice calls here are still via 2G, and 2G is the only connectivity available in many rural areas) and the chances are that 3G will be turned off whilst 2G still remains on. The original plan was to turn 2G off here in 2020, but the cost to so many consumers of doing that, together with the large loss of coverage area, means that it seems 2G may well be around for at least the next few years, maybe the next decade.

One major problem is that so much infrastructure here relies on 2G only, things like our rail system comms, lots of alarm systems, the majority of voice only and text calls and most mobile comms in rural areas (for example, we barely get any signal at all, standing outside in the garden, and if we do it's only 2G).
 

inglewoodpete

Senior Member
.... and 2G is the only connectivity available in many rural areas.
I guess it must come down to the frequencies that are used and the propagation capabilities. One reason that 2G is shutting down in Australia (only the smallest provider has their 2G network running but closing 31st March 2018, with limited rural coverage anyway) was to get better rural coverage with existing towers (3G/4G LTE 850MHz and 700MHz). The other main reason given is "higher running costs" of the old 2G technology.

On the bright side: GPRS modules and PICAXE experimenting will be cheaper for you in the UK! I wonder what the prospects are where Wolfgang lives.
 

hippy

Technical Support
Staff member
While some countries have very clear plans on 2G shut down the situation in the UK, Europe and elsewhere is not so clear. And that's complicated by the possibility of 3G shut down as 5G comes in.

One either uses 2G while one can and hopes it lasts, takes a gamble on 3G not shutting down, or goes for a 4G solution. 3G and 4G modems are commercially available with serial ports.

If a 2G solution is ultra-cheap I would imagine it to be worth the risk of a small investment being lost in a few years time as the command protocols are likely to be similar with later kit.
 

Janne

Senior Member
Old thread but I thought I'll post a reply for anyone else searching into this. I needed to have a remote sms alarm from my boiler, and I had quite a bunch of old siemens MC35i modems around. It turned out sending sms messages from the modems internal storage was quite straightforward, basically just a oneliner serout command.

Code:
serout 1,N1200_4,("AT+CMSS=1,+35840XXXXXXX,145",CR) 'AT command to send SMS from storage slot 1, phone number in international format, and 145 as address / phone number format "magic number"'
Inserting messages into the storage or writing variable messages is a bit more complicated at least with this siemens modem, as they rely in interactive serial console (thought one could assume ideal conditions and just pause the program instead of parsing the replies from the modem..), so since only needing a general alarm message I could use a pre-recorded sms.. which I inserted just using serial terminal.
On this modem the serial port's DSR and CTS lines had just enough capacity to supply the picaxe board with just the axe mostly napping and shortly flashing an indicator led, so just the modem's power supply was required.

At least around here the 2G network is likely not going away anytime soon. They are phasing out 3G, but 2G has so many devices relying on it that I doubt it'll be going away anytime soon.
 

lbenson

Senior Member
They are phasing out 3G, but 2G has so many devices relying on it that I doubt it'll be going away anytime soon.
Thanks for that information. I had feared that the phasing-out meant that the older devices wouldn't work either.
 

hippy

Technical Support
Staff member
At least around here the 2G network is likely not going away anytime soon. They are phasing out 3G, but 2G has so many devices relying on it that I doubt it'll be going away anytime soon.
That does seem to be the case, and in the UK Smart Meters are currently being rolled-out with 2G capability, many vehicle trackers and other IoT devices still rely on 2G.

The official end of 2G in the UK has now been set for "by 2033", and it appears it could shut down sooner.

The link below is to a useful page which details the expected future of 2G around the world, where 2G has closed, when it likely will -


I think the best one can do is choose something 4G upwards which will remain supported long term, choose 2G and hope it keeps running for as long as possible but be prepared to upgrade. In the UK I would guess we have two to ten years left. As 2G disappears I would expect cheaper modules supporting later technology to arrive and drop in price.

The biggest challenge to DIY IoT may be finding 'data only' packages which carry forward credit, don't require expensive contracts with monthly fees.
 

oracacle

Senior Member
From scanning through here, its looking like we are going to ecentually say good by to communications outsideof visial range of a tower - kinda defeats the point a bit.
 

Janne

Senior Member
Around here some of the new smart meters are using LTE-M and NB-iot networks for communication. NBIot especially seems like a promising candinate to eventually replace 2G - it supposedly has excellent signal reach paired with low power consumption, drawback being low-ish data rates. Modules don't yet seem to be as dirt cheap as 2G modules but will likely come down in price.
 

oracacle

Senior Member
I don't know what you would define as low data rate, but generally speaking you can't do high speed data transfer over distance without a physical connection. For high speed data you need a shorter wave length which is in turn easily disturbed by objects like buildings and hills. It's that very reason why 5g doesn't work well inside of buildings or more than about 350m from a mast. Iirc 2g is over 35km, and 4g is about 16km
 
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