secure wireless remote control - long range relay - Page 1
Forum section: electronics / rf-microwave

author: marc22
author_rank: Newbie
timestamp: September 10, 2016, 05:02:48 pm
content: Hello,I got myself involved in project of gate opening using actuator.I use arduino nano (for timing control, emergency sensors etc) and wireless remote like this ->http://www.ebay.com/itm/4-CH-Wireless-Transmitter-Receiver-Remote-Control-Switch-Relay-DC-12V-10A-315MHz-/181446904368?hash=item2a3f140a30:g:7m4AAOSwVupTqUBzEverything was working perfect, but range was not enough (while driving car, gate was not able to get opened so i was blocking a one way street and people need to wait) so i mounted external receiving antenna. Got myself a great range but stuck in other problem...Other people are opening gateBigger antenna, bigger gain, bigger range, more people in range = troubles.First of all i change couple times "id" programmed in transmitter and not i got gate opened once a week (earlier couple times a day).Probably i can find "free one" but at night when propagation of radio waves is better still someone could hit my key and don't know it...I found that impossible to treat as good job.Could anyone recommend me a remote like this one"http://www.ebay.com/itm/4-CH-Wireless-Transmitter-Receiver-Remote-Control-Switch-Relay-DC-12V-10A-315MHz-/181446904368?hash=item2a3f140a30:g:7m4AAOSwVupTqUBz"what will have some kind of encryption to be sure that only I can open gate and remotes programmed by me?I was thinking about wifi module, but still will be problem with range...Is there any out of box solution?I was thinking about doing it myself but i'm unable to create form factor that could be fit on pocket (i need one for car, couple for people to wear in pocket).I was thinking about arduino nano and digital transmission.1) Set up a encryption key shared between keychain for example 1234567892) When i want open gate, i send message to gate arduino (gate arudino respond with random numbers 987654321)3) I recevie random number and multiple by secret key and send to gate.4) gate is know secret key and key that he send so calculate and match if equal if yes then open gate (if 123456789 * 987654321 = answer then yes open .So it's "impossible" to tamper that transmission if numbers are long enough.Can anyone share out of box idea like this?I need 4 chanel NO relays, go to close when key-press.RegardsAny ideas are welcome:)

author: marc22
author_rank: Newbie
timestamp: September 10, 2016, 09:09:30 pm
content: Quote from: evb149 on September 10, 2016, 05:15:42 pmThank You for answer but i'm not sure about this.Im looking for about 700m range (most open space, and some woods) - on this chines at 315 mhz i got no problem in range.The problem with all of this devices there are designed to create a link between devices. disconnected device, make discovery, find then connect and that take time.I was thinking about bluetooth and wifi - but it's to small range and need to establish connection(i can put a outdoor antenna, but still phone inside car will have limited range, while driving) - don't looks good and safe.Transmiter is operated from battery so it should start working at key-press.What about:HC-12 433Mhz SI4463and external antenna ?at lowest baud rate?Maybe this is what i'm looking for?

author: Ian.M
author_rank: Super Contributor
timestamp: September 10, 2016, 11:31:02 pm
content: How about a range of anywhere on the planet with a mobile signal?There are off the shelf GSM relay control modules available, some even in IP68 enclosures.However you would then have the ongoing expense of a SIM only contract for the module.They invariably use some sort of security code, and can typically be activated by text message, smartphone app or normal call with a PIN. You'd want one that supports multiple codes or caller ID so you can revoke/blacklist lost/stolen phones.

author: tautech
author_rank: Super Contributor
timestamp: September 10, 2016, 11:50:16 pm
content: You can mix and match equipment from these guys:http://www.rfremotech.com/Others.htmlhttp://stores.ebay.com/RFRemotech?_trksid=p2047675.l2563To get good current ratings it's easy to cascade relays to suit your requirements.

author: LabSpokane
author_rank: Super Contributor
timestamp: September 11, 2016, 01:55:50 am
content: Get an Electron from Particle.io. Simple and takes commands over a REST API using https.https://store.particle.io/collections/electron