Tag Archives: gsm gate opener

1 Button GSM Door Entry Intercom Video

In the video Michael demonstrates our classic 1 button GSM Door Entry Intercom.  It’s been around a while now and has been refined into a very solid system with excellent audio and an easy to use programming method.

The Advent Controls GSM Door Entry Intercom System Key Features:

  • Internal Aerial for Simple and Fast Installation
  • Simple SMS Programming using Intuitive Commands
  • High Audio Quality
  • Space for up to 384 Numbers
  • Dial-to-Open Access Control
  • Lowest Price GSM Intercom on Market

The system uses a high production volume enclosure with our custom UK designed and built electronics inside.  The design of the enclosure is excellent giving good audio and protection against the elements.  As with all of our products the firmware is written in house and has been refined over time to work seamlessly with every network.

The Intercom is available on our website here for just £149 (£124.17+VAT!)

GSM Intercom

Mobile phone based Door Entry System


Troubleshooting Setup Issues for Advent Controls GSM Dialers and Relay Boards

Michael describes the most common problems users have when first setting up the GSM systems.

The installer should set up a master user number (their own phone number) before attempting anything else. However sometimes, if there is a SIM fault or aerial problem, the system will not be ready for this. The video describes the symptoms and how to resolve them.

Of course if any further help is needed please feel free to get in touch with Advent Controls

Alpha GSM Gate Opener and Alarm Dialer Schematic

GSM Gate Opener Circuit Diagram

Advent Controls Alpha Relay Board Schematic Diagram

The above figure shows an early Advent Controls Alpha GSM Gate Opener and Alarm Auto-dialer circuit schematic diagram.  There have been a few updates to the design over time but the basic elements of the design remain.

The top left hand section shows the DC to DC converter (based on the AP5004 300kHz switching regulator) which takes the 12-24VDC supply and converts it to a lower voltage suitable for running the GSM chipset and base-band output drivers.  The relay is also powered directly from this supply.  For further details see this article here.

We then move on to the opto-isolated input circuit (based on the KB817 part) which connects the outside world to the low voltage digital section on the microcontroller.  Please see this article for further details.

In the centre of the diagram we have the relay output section which is how the board outputs to the real world.  For further information please view this article.

On the right hand side of the diagram we have a very interesting circuit.  This section converts the audio output from the GSM chipset – the voices and tones heard through the phone – into a form which the simple microcontroller can understand.  For further details on how this section works please see this post.

The bottom left of the schematic shows the heart of the system – the GSM engine built around the MediaTek MT6252DA built into a seperate module by our commercial partners Quectel.  There is more information of this subsection here.

If the GSM engine is the heart of the system the PIC16F1825 microcontroller which runs our firmware is the brain of the unit.  This component is an entire computer in one chip featuring RAM, a CPU and flash EEPROM program memory (effectively the internal  hard drive).  It handles all of the GSM commands, connects the input and output to the real world, performs Digital Signal Processing (DSP) on the all the of the audio received by the board and stores all of the user telephone numbers and setting.  This device is what allows our board to be so compact.

PCB fiducial markers for accurate placment of the GSM module on the alpha relay board

GSM Module Fiducial Markers

We were asked what the two circles with dots in the centre were.  These are fiducial markers which appear on the PCB.  They help the pick and place machine which assembles the board accurately position the module in to place.  The placement of this component is critical to ensure the antenna matches the GSM output.

GSM Roller Shutter Remote Control Board with Dead-Man Operation

GSM Roller Shutter Remote Control in Enclosure

Control your roller shutter or garage door with your mobile phone

Today we added our roller shutter remote control board to the website.  We’ve had this one for a few months now but have finally got some quantity in stock.  This board is great for controlling roller shutters with separate inputs for opening and closing the shutter.  With the ‘CHANNEL ALT’ command you can set the call relay to alternate on each call.  This allows one call to open the shutter and the next to close it… and so on.

The new ‘Ring Mode’ (which is now also available on our Alpha GSM Gate Opener Board) allows the caller to operate the shutter whilst the call is ringing – stopping as soon as the call is ended.  This makes the system ideal for controlling so called ‘dead man’ shutters where the switch must be held during the entire movement of the shutter.  There is a good demonstration of this in the video below.

GSM Roller Shutter Remote Control

Control your roller shutter with your mobile phone

The Roller Shutter Remote Control Board is available on the Advent Controls website


PAYG or Contract SIM for Alpha GSM Gate Opener

Hi,  Will I need a contract SIM or will a Pay As You Go SIM work with the GSM Gate Opener? Thanks,


Hi David,

Thank you for your email.  It depends on what you intend to do with it.  If you only occasionally anticipate getting SMS messages from it (for things like checking numbers, checking signal strength etc…) then a PAYG SIM with minimal credit will probably be good enough.  You can get a pre-paid SIM from GiffGaff (which uses the O2 network) with as little as £5 credit on it.  Or you could use Vectone (we use these) who use the EE network.  They have good coverage as they are the combined T-Mobile and Orange network.  http://www.vectonemobile.co.uk/pay-as-you-go/free-sim-with-top-up/step1.aspx

If you use a PAYG SIM you must setup the SMS or DIAL command so the board occasionally makes a call/text to keep the SIM alive e.g.

SMS 07000000000,30.  will send a text every 30 days to 07000 000 000




SIM Card Selection for GSM Gate Openers and Auto-Dialers


We get asked a lot ‘what SIM should I use’ and ‘will X-brand SIM work?’ with our Alpha GSM boards.  Well the simple answer is any apart from 3 mobile.

Our board is a quad band board (http://www.adventcontrols.co.uk/gsm-gate-opener.html).  In the UK and Europe (indeed most of the world) the ‘2G’ standard GSM frequencies are 900/1800MHz and established networks, such as Vodafone, O2, Orange all have the infrastructure to support these bands.  The reason ‘3 Mobile’ doesn’t work with this type of equipment is because they never invested in it and just went straight to the 3G frequency of 2100MHz thus limiting their compatibility to 3G only equipment.  ‘3’ is the only network which does not have a 900/1800MHz infrastructure.

In the Americas they had a slightly different set of frequencies at 850MHz and 1900MHz making older ‘dual band’ equipment incompatible with the rest of the world.  Quad band products like ours mean no matter where you are in the world you will be able to find a network to support our products.

The final word on frequencies is that the 4G network operates at 800MHz and 2600MHz and if an operator started up who only offered 4G compatibility they would also not work with traditional GSM gate openers and auto-dialers (and all but the very latest phones!).

Vodafone, O2, Orange and T-Mobile all own 2G network infrastructure and also the licenses to operate on these frequencies so any of these networks will be compatible with our products – even if they offer 3G services.  The board will select the 900/1800MHz frequency from the SIM card and find the network using one of these bands.

Then we have the MVNOs (Mobile Virtual Network Operators) that resell the major network’s products as their own.  These are companies like Virgin Media (T-Mobile), Talk-Mobile, Vectone (EE which is in turn T-mobile and Orange) and so on.  You can often find a better deal using these MVNOs than you can through the major networks directly.

There is one MVNO you should avoid and they are called ‘shebang’ – they exclusively use the Three Mobile 3G only network!

Up to now we have been recommending Vectone mobile simply because they provide good value and also offer a £1 per month contract with up to 50 minutes.  You can find this deal on their website at:


If you have any queries please get in touch.


Alpha GSM Pulse or Toggle and Call Handling Question

>A few questions on its operation.
>1) when you ring the device, if it recognises a valid number just it answer the call or simply >open the gate?
>2) when it recieves the command to open the gate, just it flip the relay and hold the relay in >that sate until it recieves the close command, or does it pulse the relay for a set period?

Hi Dave,

Thank you for your questions. By default it will ring out when you call it whether it recognises your number or not. However you can set it to automatically reject all calls… [or even reject when open, connect when closed (or vice versa)]. To reject all calls you would send it the following message:

Reject all

To go back to the original state:

Reject never

By default it pulses for 2-3 seconds when you call it. Again you can change this to latch on and then off each call using the following command:

RLYMODE TOGGLE (toggle relay between calls)

…and back to normal with:

RLYMODE PULSE (relay mode pulsed – normally open)

If you have any further queries please feel free to get in touch.