Tag Archives: GSM Door Entry

Gold G2 GSM Intercom Door Entry Phone Update

January has proven to be a busy month with many trade and online orders for our ever popular GSM Auto Dialer system (GSM Dialer).  We’ve also taken on a new member of staff, Kelly, to handle orders for this product.  Hopefully for her sake the next couple of weeks will be a little quieter!  It would also allow further progress on our new Gold series of intercoms.

GSM for AndrewWe have been installing the first of our Gold Series GSM Door Phone Intercoms which is the Gold G2 Model.  However they are still in short supply and we’re still working on the firmware.

The early versions have been using the Capacitive Sensing Module on-board the PIC microcontroller.  This has proven highly reliable and accurate in the field however in theory this module is susceptible to electrical interference.

CSM Scope View

CSM Pad Trace

The CSM module generates a frequency dependent on the capacitance applied to the pin of the chip.  However it is possible for the touch pad to pick up high strength electrical noise and start oscillating at the frequency of the noise.  This would be seen as a press even though nobody touched it.  In practice we have not seen this but we also developed an alternative software based decoder which measures the voltage on the touch pad after it has been discharge and charged by the Analogue to Digital Convertor (ADC) sampling capacitor.

CVD Touch Pad Trace

CVD Touch Pad Trace

This technique of measuring the pad charge and then discharge into the same capacitor is known as a Capacitive Voltage Divider (CVD).  This method is very resilient to noise and electrical interference but does require more CPU processing time.  It is likely to be implemented across all of our Gold GSM Intercoms and will soon be behind the touch pads of our G2 unit.  When we have a full keypad version of the intercom available it will be important to use this technique hence it is being developed now.

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

Week Ending 08/08/14…

Just a little post about what is new in the world of Advent Controls.  We’ve had some rough drawings and ideas about a new concept in the design of intercoms in general.  What we want as installers is a nice flush mount finish but without having to spend hours smashing bricks out of a wall.  The simplest installations are simple surface mount units like our basic 1-button GSM intercom (http://www.adventcontrols.co.uk/gsm-door-entry.html).  These are great for a quick installation but ideally for vandal resistance and aesthetic reasons we would prefer flush mounting.

Panel Intercom 1st Iteration

Panel Intercom 1st Iteration

The answer is an ultra thin panel style intercom.  We finally started prototyping the PCBs for this design this week and it’s coming along nicely!  Currently we’re working to an 8mm thick design but who knows how thin these will be eventually.  I really believe this is the future for intercom design as they look fantastic, are simple to fit and are extremely strong solid units.

Designing the Panel Intercom

Designing the Panel Intercom

Electronics wise one of the hardest design aspects we’ve found has been to add bulk capacitance for AC voltage smoothing.  Second to this is the speaker thickness and displaced volume (which affects the efficiency of the audio system).  We do believe we have an answer to this on forthcoming designs which could see the thickness of the unit drop below 5mm!  For now we’re keeping with conventional design and sacrificing ultimate packaging efficiency.

Front Panel Design Layout

Front Panel Design Layout

GSM Gate Intercom Animation

I don’t know who did this but ‘Nigel’ has the right idea (although he should have used one of ours – ours is an all in one unit!).  I like it!


Save yourself time and money and buy an Advent Control One-Piece GSM Door Entry Intercom from here http://www.adventcontrols.co.uk/gsm-door-entry.html