paradox-security-arduino
Arduino code to send SMS notifications and events via WIFI for Paradox Home Security system
What does it do?
Using Arduino Mega attached to Paradox Home Security System Megallan this can send SMS messages and log events from Security System via WIFI
Similar commercial products cost > 110€, with Arduino this can be achieved with around ~15€
How does it work?
Arduino mega is attached to Paradox Serial interface.
Events received via Serial interface are processed and sent via UDP over WIFI to a Raspeberry Pi (you can use any other hardware) which are forwared to AWS DynamoDB and later can be viewed via Android App
Critical events - such as alarms, fire alarms, or any trouble events are sent via GSM SMS
RaspberryPi code that sends events to DymamoDB can be found here
Android application where you can view events can be found here
Hardware used
- Cheap Chinese clone of Arduino Mega - $7.63
- ESP8266 wifi module (Delivery of events over WIFI via UDP) - $2.98
- SIM800L GPRS GSM Module (Critical event delivery over GSM via SMS) - $5.22
- LM2596 Power Supply Buck converter (for SIM800L module) - $1.5
- Donation to Arduino - $10
Wiring
I've used Arduino Mega because it has 4 HardwareSerial ports. While in theory all of this should work with SoftwareSerial, I couldn't manage to read Paradox Serial Interface with SoftwareSerial on Arduino Pro Mini, so it was easier and less hassle to setup Arduino Mega
- Serial is used for uploading code and debug messages
- Serial1 is attached to Paradox Serial Interface
- Serial2 is attached to ESP8266
- Serial3 is attached to SIM800L
How to use this?
Create config.h file from sample config.h.sample, wire everything up and attach this to Paradox Serial interface.
Everything is powered from Paradox Serial Interface (which gives ~13v) - it has enough juice to power SIM800L, which is really power hungry (make sure you get the voltage right with LM2596, I had to use 4v)
Notes on code
SMS delivery is implemented directly via AT commands by using queue, so expect a 5-10 second delay between actual event and sms delivery.
Wifi should work almost instantly.
I also epxerienced random reading fails from Paradox Serial Interface, therefore there is a safety switch which restarts HardwareSerial after 3 consecutive failed packet decode attempts
Why DynamoDB ? Cause it is free, and you can simply leave your raspberry pi on DMZ
Why not wire directly everything to RaspberryPi? My raspberry does a lot of other things (NAS, Motion processing, etc.), also Paradox Security System has a backup power, so critical events will be always delivered via SMS.
Credits
This work is based on wonderful post from Martin Harizanov Interfacing with Paradox home security system attempt 2