Category Archives: GSM Gate Opener

Should I buy a 3G intercom or alarm dialler?

We get asked a lot when the 2G network will be shutdown. In Europe, on the whole, nobody really knows yet.  The general consensus is that the 3G network will be shutdown first around 2020 and 2G as late as 2025.  In some countries 2G is no longer in operation (USA, Australia, Japan, Singapore…) but this is not the case in Europe.

Vodafone-will-not-switch-off-2G-until-2025

old phone

2G Phone

4G is obviously great for data but until recently many phone masts did not support audio on 4G/Long Term Evolution (LTE).  Audio on 4G uses a system developed by Qualcomm known as VoLTE.  Originally 4G was data only and your phone switches to 2G or 3G for calls.  Audio on 4G is really only being implemented now by most networks.

https://www.4g.co.uk/what-is-volte/

So, that leaves 2G and 3G for handling calls.  3G uses 2100MHz in Europe.  In general a higher frequency will result in a shorter range.  Also, on the higher frequency bands, your phone is limited by the amount of power it can transmit to 1W.  For comparison, on 900MHz 2G your phone can transmit 2W of power giving a better range.  The lower frequency of 2G and 4G bands will also penetrate walls better than the higher frequency 3G band.  3G also only has one frequency band allocated to it whereas 2G has two.

Europe-could-go-alone-in-waving-goodbye-to-3g-first

3G phone

Early 3G phone

3G therefore doesn’t really offer anything anymore.  It is slower than 4G for data and the coverage is usually worse than 2G which is why the network space is better allocated to 4G, 4G NB and 5G.

So, should you buy a 3G intercom or dialler?  We were developing 3G products but decided to stop simply due to their limited life-span.  They will work on 2G when 3G is shutdown but why pay the extra for a 3G unit?  There is one reason; in the UK the 3 network only offer 3G & 4G so you can only use a 3G unit on this network.  They may continue 3G beyond 2020 for this reason.  Also you may find you have no coverage in your area on 2G but there is coverage on 3G.  This would of course be a temporary solution for you!

3G Alarm Dialler PCB

3G Alarm Dialler

We gave up on 3G and I would not recommend paying extra for a 3G unit.  We are developing 4G products but these have many extra complications with VoLTE and network specific frequency bands so our 4G units are taking some time to develop – but 4G is the future!  We expect to be first with our 4G diallers and intercoms in Europe.

VoLTE Intercom

4G VoLTE Intercom

For further reading please see:

https://www.mobileworldlive.com/featured-content/top-three/operators-vendors-forecast-long-life-2g/

 

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Gold Mini GSM Intercom: production, testing, inspection

Finally we saw our new Mini Intercom enter production.  It uses a new and novel manufacturing technique which required several iterations to get right.  The end result is a solid, strong lump of fiber glass with a pretty black and gold finish – and yes that’s real gold!  At just 4mm thick this intercom has the appearance of a flush mounted unit but is in fact surface mounted; a common trait for all our Gold intercoms.

4mm thick intercom

Side view

The intercom is fully waterproof. We use the gold finish as it is non-corrosive.  The three parts of the intercom are brazed together forming a water tight seal around the unit rather like a copper pipe is soldered to form a seal.

soldering joint x-ray

Solder seal x-ray

After the soldering process we inspect the intercom using an x-ray to ensure the seal has been formed around the entire perimeter of the unit.

QFN x-ray

Processor soldering inspection

v1.07 Software Release for setting up Diallers and Intercoms

Our software allows you to change your dialler and intercom settings, numbers and messages remotely using the internet.  It requires a small amount of data allowance to be available on your SIM.  A session will use a couple of kB.

v1.07 will work with any firmware release from 5.10 onwards.  We can remotely update your dialler and intercom with the latest firmware if required (you must have at least v5.10 to start with).

The software is available from our Downloads page:

http://www.adventcontrols.co.uk/pages/downloads

Please note currently we do not require installation of the software which is available as a raw EXE file.  If you download this from our website you can trust it.  You may need to click ‘run anyway’ on the Windows security message box.  We will release an installation version over the next few weeks.

May 16 Update Video: Dialler PCBs, Gold Intercom and PC Software

Video Timing

  • New Roller Shutter PCB (2-in 2-out PCB) 0:20s [C4 Webpage ]
  • D4 Analogue Voltage Measurement and 6 input PCB 0:36s [D4 Webpage]
  • D4 PCB also PCB tested in software 3:20s [D4 Webpage]
  • G2 GSM Intercom 0:55s [GSM Intercoms]
  • New A4 PCB 1:55s [2-Input GSM Dialler]
  • PC Control Software 4:40s [PC Software Download]

In the video we mainly demonstrate the PC software.  This connects via the internet to your PCB and allows you to view settings and numbers as well as monitor the system live.  The PC software in on the whole done we’re waiting for our server software to be complete.

New GSM Dialer and Relay products due this month

Juts a quick post to show you our new PCBs.  These are still as on the panel which goes through the screen printer, pick and place machine and oven.

You asked for more inputs on the dialer PCBs so we’ve given you them!  6 in total but these are not all just more inputs we’ve added two analogue inputs.  These are ideal for applications where you would like to measure a voltage remotely or be alerted to a sensor measurement change by SMS or call.

GSM Alarm Dialer with individual zone detection

GSM Dialer and SMS Sender with Analogue Inputs

The analogue inputs have applications in burglar alarms too allowing you to monitor individual zones which do not have a open collector output associated with them.  You can just measure the voltage change of your zone when alerting and get an SMS just for that zone whether the alarm is armed or not.

We have also added a low power mode and supply voltage sensing.  GPRS setup and updates along with email alerts will also be available in the new year using this PCB.

GSM Dialer and Roller Shutter Controller

GSM Relay and SMS Sender Board

The new C4.01 PCB shown below has similar features to the D4.01 dialer as above but has 2 logic inputs and 2 relay outputs.  This is ideal for controlling roller shutters.

PAYG SIM Card Deactivation

When using Pay As You Go (PAYG) SIM cards in equipment such as dialers and gate openers you should be aware that the network may chose to deactivate your SIM card should you not meet the minimum usage requirements.  In the UK the strictest networks require at least a call or text message to be sent once per quarter – Lebara Mobile require 1 call/SMS per 3 28 day calendar months.

For details of the terms and conditions for each network I recommend following this link with an excellent article written on the subject:

http://kenstechtips.com/index.php/payg-inactivity-account-termination-and-credit-expiry

Further details can be found here on the basis for these policies:

https://community.giffgaff.com/t5/Blog/Recycling-mobile-numbers-giffgaff/ba-p/8211666

Our GSM equipment has two SIM card Keep Alive functions which automatically send an SMS or dial a number to keep your SIM card within the terms and conditions of the network.  All products have the Keep Alive Text feature which sends an automated SMS message at user specified intervals to their chosen number.  This is set up as follows:

KAT 07000000000,28.       Sends a keep alive message every 28 days to 07000000000

Dialers and Gate Openers with firmware version 3.18 or later additionally have the ability to dial numbers where a voice call is a requirement.  This is set up using the following command:

KAC 01512834306,80.      Dials 01512834306 every 80 days

Should the call go unanswered it unit will retry 4 times and will then send an SMS to the first master number with the following text ‘KAC@Fail’.  In this case a manual call should be made with the following command:

Dial 01512834306.     …or the number of your choice

Where your network requires a call to be made but your device has firmware prior to F3.18 we recommend setting the Keep Alive Text message to remind you to make a manual call for your required interval using the dial command.  Ensure the call is answered.

What’s new in July

We ended June having brought our new Gold G2 2-Button Intercom into full production and having restocked our old 1-Button internal aerial unit.

GSM Intercom

Advent Controls G2 Intercom

We have a new PCB which will form the basis of all of our dialers and gate/shutter openers going forward.  It features an ultra-low power mode, more inputs and outputs, space for a voice unit and Bluetooth.  The chip on the PCB has a larger program memory (like the hard drive of a PCB) giving us space to add more features.  The power supply design is more rugged too allowing for higher voltages and better surge protection.

B3 PCB

GSM Roller Shutter Controller

We’ve finally given up on the Circuit Switched Data (CSD) system we used for remotely connecting to devices in the field and have revised the software to use the GPRS packet data system.  We chose CSD as it meant your SIM did not require data and there was no need to tell the GSM unit your network’s APN (Access Point Name) e.g. giffgaff.com…  The problem is CSD does not really work at all never mind reliably.  Quectel have dropped support on the new modems we are using so it was time to switch to GPRS.

GSM assembly code

We’ll be using GPRS to dial in in future

There are huge benefits though.  The newer PCBs including our Gold G2 Intercom can have a full firmware update over the internet using GPRS.  We have also added the ability for the dialers and gate openers to send emails whenever activity is detected.  Eventually we will either offer our software to the end user or create a web interface for setup to be done online.

Setup GSM dialers and intercom online

Advent Controls Web Interface Software

New features – feedback definitely welcome!!

  • Dial, SMS and email
  • Bluetooth Setup
  • Low power modes
  • PC interface software
  • Ability to email list of settings and stored numbers
  • 2-In, 2-out PCB due August
  • Keep Alive text to display balance

Michael Beaver, Director