When a caller presses the gate intercom, I'd like the call to connect to my asterisk-embedded pbx device for handling. I only see really expensive VOIP gate intercoms. How is this achieved on a tiny budget? Or even if it somehow connects to one of my pbx FXO ports via analog, that would be okay too, if possible? Any ideas or suggestions?
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VOIP Gate Intercom
- Thread starter Milano
- Start date
I must be missing something obvious here. You can get a SIP phone for as cheap as like R500.00. What makes a door phone so special that it costs 10x that amount? What am I missing? Are there no cheap VOIP intercoms / SIP doorphones?
gmza
Well-Known Member
A cheap SIP phone won't be waterproof, won't have a durable aluminium face and won't connect up to a relay to trigger the gate/door mechanism.
The door phones are designed for heavy abuse (rain, hail, etc) and for connection to a gate motor relay.
That being said, if cost is a factor, it is almost definitely going to be a lot cheaper to build a waterproof enclosure for a cheap phone and some sort of home-brewed relay system. By no means elegant nor simple, but certainly a lot cheaper.
The door phones are designed for heavy abuse (rain, hail, etc) and for connection to a gate motor relay.
That being said, if cost is a factor, it is almost definitely going to be a lot cheaper to build a waterproof enclosure for a cheap phone and some sort of home-brewed relay system. By no means elegant nor simple, but certainly a lot cheaper.
Thanks
Yeah, I just can't justify R4000 to R6000 on this. Will have to take the cheap and nasty approach here 
Thanks
I am also in the process of looking for a reasonably priced sip intercom. I wanted WIFI, but that doesnt seem very common.
I have found this one to be the most cost effective:
https://scoop.co.za/download/fanvil/FAN-I12.pdf
Brandon
Well-Known Member
Faced the same dilemma in 2010. Back then the cheapest options available locally were R5k and over. Besides the price I wasn’t keen on putting kit that expensive out on the street.
Built the below instead (mostly from old parts):
The street side interface is a rewired BPT intercom. The rest is in a IP65 cabinet.
Updated the phone board to a Fanvil X3 from an old Atcom to support g722. Linked to the home network with a Mikrotik Groove, powered by 12v ac supply for the gate. Opening/closing switching done with a rectified relay connected to a grandstream ata and custom ring cadence.
The BPT’s button is connected a delay-off relay and the speakerphone button on the phone board. The delay relay prevents a second button press from de activating the speakerphone and terminating the call. The phone is setup to immediately off hook dial as well as auto answer incoming calls.
The ata has a diode, capacitor and relay connected to the analogue phone line, the diode will only allow current to the relay when the line is ringing (dc normal vs ac ringing). Correct timing is achieved with combination of a fixed ring time on the ata’s extension from asterisk and a long ring/pause cadence in the ata.
Part list:
1) delay-off relay
2) LED driver circuit (ZXLD1350ET5TA)
3) Isolation audio transformer from old modem
4) LM386 audio amp for intercom speaker
5) LM7805 for 5v supply to phone
6) PoE for Mikrotik Groove
7) Grandstream HT-502 and relay
8) 12v supply regulator and battery charger
9) LM7809 for 9v supply to LM386 amp
10) Fanvil X3 board and LCD
11) Link to BPT mic, speaker, button and LED’s.
Built the below instead (mostly from old parts):
The street side interface is a rewired BPT intercom. The rest is in a IP65 cabinet.
Updated the phone board to a Fanvil X3 from an old Atcom to support g722. Linked to the home network with a Mikrotik Groove, powered by 12v ac supply for the gate. Opening/closing switching done with a rectified relay connected to a grandstream ata and custom ring cadence.
The BPT’s button is connected a delay-off relay and the speakerphone button on the phone board. The delay relay prevents a second button press from de activating the speakerphone and terminating the call. The phone is setup to immediately off hook dial as well as auto answer incoming calls.
The ata has a diode, capacitor and relay connected to the analogue phone line, the diode will only allow current to the relay when the line is ringing (dc normal vs ac ringing). Correct timing is achieved with combination of a fixed ring time on the ata’s extension from asterisk and a long ring/pause cadence in the ata.
Part list:
1) delay-off relay
2) LED driver circuit (ZXLD1350ET5TA)
3) Isolation audio transformer from old modem
4) LM386 audio amp for intercom speaker
5) LM7805 for 5v supply to phone
6) PoE for Mikrotik Groove
7) Grandstream HT-502 and relay
8) 12v supply regulator and battery charger
9) LM7809 for 9v supply to LM386 amp
10) Fanvil X3 board and LCD
11) Link to BPT mic, speaker, button and LED’s.