We’ve already seem boxed WiFi and Bluetooth wireless relays that can be used to turn on and off appliances using a smartphones or web applications, but I’ve just been made aware that GSM relay controllers such as RTU 5025 could also be a good options since they allow for authentication using the mobile number, can be used with any phone, not only smartphones, and don’t cost anything to operate, beside the eventual maintenance cost of the SIM card inside the device, since the relay does not actually answer calls. It can also send an SMS to the owner each time the relay is activated, in which case the cost of SMS might have to be considered.
RTU 5025 specifications and key features:
- Connectivity – GSM PHASE 2/2+@ 850/900/1800/1900 MHz with SIM card slot + GSM antenna
- Output Relay – 3A/240V
- Rated Voltage – 12V/1A
- Working Temperature – -10 to 60 Degree Celsius
- Storage Temperature – -20 to 60 Degree Celsius
- Relative Humidity – 10 to 90% (No condensation)
- Support up to 64 authorized phone numbers can be configured by SMS
- Terminal Block – 01+/01- to motor, Siren, IN1/IN2 to sensor
- Dimensions – 107 x 119 x 24 mm (L x W x D)
- Weight – 163g
This product is mainly used as a gate opener which explains the siren and sensor pins, but it could be used to control other machinery remotely, and other optional sensors sold with the device include PIR sensor, glass break sensor, magnetic window sensor, temperature sensor, information beam fence, and vibration sensor.
The user manual for RTU-5025 (different enclosure) shows how to set the password, add users, i.e. mobile numbers, enable/disable the alarm triggered by the sensor pins, relay close time, etc… using SMS commands.
RTU 5025 is sold for $44.72 on Chinavasion, but you can also purchase it, or similar models, on Aliexpress, GearBest, eBay, etc… Again bear in mind that 2G networks are or will be phased out in many countries, and you may consider the 3G version instead, selling for $85 on Aliexpress.
Thanks to Onebir for the tip
Jean-Luc started CNX Software in 2010 as a part-time endeavor, before quitting his job as a software engineering manager, and starting to write daily news, and reviews full time later in 2011.
Support CNX Software! Donate via cryptocurrencies, become a Patron on Patreon, or purchase goods on Amazon or Aliexpress
Caller ID can often be easily spoofed, I wouldn’t trust that as authentication, especially for a gate opener…
@JM
Good point; OTOH, they have to know both the number to dial & caller’s number. I think one use case is delivery yards etc, where some will be around but doesn’t want to have to manually open the gate all the time.
Well I’m no expert but I think you can get both numbers by running something like an IMSI-catcher, ie a fake base station using software like OpenBTS and a SDR, especially the 2G GSM version
But true it might be convenient for something that is already secured by other means. Just don’t expect a lot of security out of this.
How do you resit this device ? A friend gave me one as a gift but he already program his cell number as the admin,