G+_Ben Reese Posted December 2, 2017 Share Posted December 2, 2017 Looking for suggestions/advice. A purchase a cheap wireless security system off Amazon and I helped install it. The range of the 433 Mhz sensors is terrible, so I need to extend it somehow. My first thought was to use transmitter/receiver pairs to create a repeater, but I'm not sure that will gain a whole lot either. So here's a couple options I've come up with... * Repeater as mentioned above * Repeater as above with cantenna on the transmit side * Take the 433 Mhz from sensors and transmit with 2.4 Ghz to another Arduino that translates back to 433. * Read the signal on a Pi Zero-W and send over Wi-Fi to another Pi near the base unit. I already have some supplies to do most of this and anything will be better than what he currently has. Thanks in advance! Link to comment Share on other sites More sharing options...
G+_Rud Dog Posted December 2, 2017 Share Posted December 2, 2017 Played around with the RFM69 but never really got it working but this guy did. This is one video where he is reviewing signal transmit and receive distances. He has couple others buried on his video youtube channel. Link to comment Share on other sites More sharing options...
G+_Paul Hutchinson Posted December 2, 2017 Share Posted December 2, 2017 While repeaters may work the 433MHz band is so, crowded, noisy, and heavily restricted on usage I think your best bets are your last two options. Trying to expand the range of the 433MHz signal will almost certainly end up making such a noisy environment that garage door openers, remote thermometers, car remote starters and locks may start acting strange due to transmissions lost in the increased noise. In particular the directional antenna idea could be disastrous to nearby neighbors devices leading to a visit from the FCC and being ordered to disconnect the device and never turn it on again. Link to comment Share on other sites More sharing options...
G+_J Miller Posted December 2, 2017 Share Posted December 2, 2017 Hire an alarm guy to hard wire your sensors. It will be the best money you can spend. Especially if you do not want wireless falses signal failures in the future. Link to comment Share on other sites More sharing options...
G+_Rud Dog Posted December 2, 2017 Share Posted December 2, 2017 Paul Hutchinson RFM69 comes in different flavors (Frequencies) may they would be more beneficial. And you don't have to use the family of RFM69 there are others on the market in fact I think Kevin discusses this option. Link to comment Share on other sites More sharing options...
G+_Paul Hutchinson Posted December 2, 2017 Share Posted December 2, 2017 Rud Dog Nice to know thanks. It would be better to create a system that reads the alarm's 433MHz sensor signals, repeat them at 915MHz, and convert them back to 433MHz at the other end. However it would likely be easier to go the WiFi/2.4GHz route since WiFi is a fully implemented protocol that is likely already, or can easily be made, available throughout the home. Another factor favoring WiFi is that the simple low cost 915MHz transceivers like the SparkFun units used fixed frequency communication vs. WiFi's spread spectrum. With fixed frequency if there is any other system in the home already using the 915MHz band (e.g. older cordless phone or weather station designs), then adding a new source can make both systems transmission reliability bad. Link to comment Share on other sites More sharing options...
G+_Ben Reese Posted December 2, 2017 Author Share Posted December 2, 2017 J Miller I'd love to do hard wired. Just not in the budget, thus the $200 DIY kit. (I was not consulted before purchasing - just the guy that gets to help make it work). Paul Hutchinson the 2.4 Ghz radio I have are NRF24L01+. Wi-Fi is available - just wouldn't work with these radios (unless there's some implementation I haven't explored yet). It's tempting to just get some Pi Zeros for relaying and call it done. Then I could implement MQTT for more expandability.... Hmmmm. Link to comment Share on other sites More sharing options...
G+_J Miller Posted December 2, 2017 Share Posted December 2, 2017 Yea, I know Ben but is your security system really something you want to go cheap on? It is kinda buying cheap brakes for your car. Do you really want to have a sensor not work because of wireless problems? Even worse, ignore a true sensor trigger because the falses caused you to not care any more? Besides you can get a wired or wireless complete alarm system that is integrateable with control systems for less than 150$ and install it yourself. 007systems.com - DSC Alarm Power Series 1616 Even has monitoring for under 10$/month. Just a thought. Do not get stuck in someones cheap closed system. Link to comment Share on other sites More sharing options...
G+_Rud Dog Posted December 2, 2017 Share Posted December 2, 2017 Not sure the contents of the entire conversation but did get this back from Kevin, as far as RF verus WiFi maybe either one could be used. store.linksprite.com - ESP8266 Serial WIFI Module Link to comment Share on other sites More sharing options...
G+_Travis Hershberger Posted December 3, 2017 Share Posted December 3, 2017 I think your going to find that fixing the purchased system will be more expensive than getting a proper one. Link to comment Share on other sites More sharing options...
G+_Ben Reese Posted December 4, 2017 Author Share Posted December 4, 2017 J Miller? I've been thinking, and I'm curious how would 433Mhz sensors cause false positives? I borrowed one extra sensor, and when I scanned it the sensor transmitted a unique 12-digit code - pretty difficult to fake. I could see if there's a bad reed sensor on a door or bad PIR sensor, but I think the technology is mostly the same there. Yes, the signal could be jammed and I understand the noisy environment argument - just like on any other wireless system. Just curious what else might be creating the same long code. Link to comment Share on other sites More sharing options...
G+_Ben Reese Posted December 4, 2017 Author Share Posted December 4, 2017 And thanks everyone for the feedback. I'll be comparing the range between this and the NRF24L01 chips. If neither seem adequate, then I guess I'll have to use Wi-Fi. Link to comment Share on other sites More sharing options...
G+_Rud Dog Posted December 4, 2017 Share Posted December 4, 2017 Ben Reese Post your project give us the full picture. Thanks Ben. Link to comment Share on other sites More sharing options...
G+_J Miller Posted December 4, 2017 Share Posted December 4, 2017 Ben Reese, all sensors can false, even wired. At least with wired you can trace it down pretty easily and there are no batteries to worry about. With wireless it is a guessing game of trial and error unless you plan on monitoring and recording that scanner you have 24/7. Link to comment Share on other sites More sharing options...
G+_Ben Reese Posted December 4, 2017 Author Share Posted December 4, 2017 J Miller No offence, but still not buying it. Each sensor transmits a unique code (this one transmits 2: one for open and one for closed). Each sensor has to register with the base unit and it ignores all other sensors. Each registered sensor can be given a unique name. So, tracking down misfires should be just as easy on wireless as wired - unless I'm misunderstanding something. I completely agree that wired>wireless, but I don't think I'll be able to convince him at this time. Link to comment Share on other sites More sharing options...
G+_J Miller Posted December 4, 2017 Share Posted December 4, 2017 None taken. Nothing to buy here Ben, just the facts as I have some experience here. My point here is not what the sensor does. It is in wireless in general. it is by definition less secure and prone to falses. If it works great for you, you will be happy as a clam. But if you start having problems, good luck. And it seems like you are having problems already as you posted earlier. If you had a wired system you would have figured it our by now and could easily fix it. Link to comment Share on other sites More sharing options...
Recommended Posts