Fix 2 RF receivers reacting to same RF remote [SOLVED] - Page 1
Forum section: electronics / beginners

author: downloaders
author_rank: Contributor
timestamp: June 20, 2018, 11:07:09 pm
content: I bought 2 emitters and 2 RF receivers for some electric blinds, but both receivers react to both remotes.The receiver learns its remote by pressing a button on the receiver to get into pairing mode and then pressing a button on the remote and they are paired.This is far fetched, but can I replace the crystals on one receiver and emitter so they don't interfere with the other one?The crystal I have on the receiver is a 4.897 and on the emitter a NDR 3208 j3.I tried to look up what frequencies they work in but on the 4.897 i got 4.897 MHz and on the NDR 3208 j3 i got 315MHZ so I don't even understand how they communicate with each other.Are there other sets of crystals that would also be a match and replace them? So they don't interfere with the other remote?Or is there any other solution for this issue?

author: w2aew
author_rank: Super Contributor
timestamp: June 21, 2018, 04:01:19 am
content: Doubtful that you can change the crystals to fix the issue.Since there is a pairing operation - have you tried pairing one set the the other completely powered off (battery removed), and then repeat the process for the other? Maybe they'll pair with a unique code so that they only respond to the transmitter they're paired with.

author: Wirehead
author_rank: Regular Contributor
timestamp: June 21, 2018, 08:28:43 am
content: Quote from: downloaders on June 20, 2018, 11:07:09 pmYou're using the wrong frequency in Europe and are violating the law.. the ISM band in Europe is 433Mhz - You have the US version of the transmitter

author: downloaders
author_rank: Contributor
timestamp: June 21, 2018, 10:03:47 am
content: Quote from: w2aew on June 21, 2018, 04:01:19 amI have tried pairing it today with just one of the sets on, then the other, but same issue :/

author: downloaders
author_rank: Contributor
timestamp: June 21, 2018, 10:05:54 am
content: Quote from: Wirehead on June 21, 2018, 08:28:43 amDon't we always violate our law a bit for our blinds?But thanks, any way of changing the crystals to 433Mhz?

author: PA0PBZ
author_rank: Super Contributor
timestamp: June 21, 2018, 10:50:51 am
content: Is there any way to give the transmitter a unique code or are they coming pre-programmed? What are the chances that you received 2 transmitters with the same code?Any links to the actual product, or any pictures?

author: Wirehead
author_rank: Regular Contributor
timestamp: June 21, 2018, 10:54:40 am
content: Quote from: downloaders on June 21, 2018, 10:05:54 amNot if 315MHz is smack in Defence Systems radio spectrum.. Probably cheaper buying new 433MHz transmitters.. You could ask the seller of the modules..

author: downloaders
author_rank: Contributor
timestamp: June 21, 2018, 11:43:19 am
content: PA0PBZ: No, the remotes don't have a setting for channels. the receiver learns by pushing a button on the transmitter. This is the product name: JW-T02Wirehead: Thanks for your input, but if in 433, the issue would be the same and a crystal costs a fraction of the product.

author: PA0PBZ
author_rank: Super Contributor
timestamp: June 21, 2018, 11:54:29 am
content: Quote from: downloaders on June 21, 2018, 11:43:19 amYes, I understand that, but that implies that the transmitters have a unique code, and that should have been set in the transmitter... Also, it seems that the receiver can be paired to multiple transmitters. Maybe you have to reset the receiver and program it again? Unfortunately I could not find a manual online so how to reset the receiver I have no idea.

author: downloaders
author_rank: Contributor
timestamp: June 21, 2018, 02:00:35 pm
content: PA0PBZ: thanks a lot for your ideas, with your help I was able to solve it.First things first and because I also want to leave something here for the next person who has this problem:This is how to bind and unbind.(1) remote control learning: learning button LED light into learning mode, press any button LED flash three times normally on later, said learning success and wait for a remote control;(2) remote delete: executable when lost or new remote control remote control after the first remove the learning process, hold down the learning button for 8 seconds, the LED under the slow flash 5 said all the ID of the remote control, if you want to learn do the remote control function.As to how I solved it, I honestly cannot explain it. After reading what you wrote, I unbinded the first receiver and suddenly only one of the remotes worked with the other receiver. Then I paired the receiver again with the remote that was not working for the other receiver and all started working, each remote now just works on one of the receivers.Drew it up, maybe it could help someone:

author: Buriedcode
author_rank: Super Contributor
timestamp: June 21, 2018, 02:12:26 pm
content: It sounds like both remotes send exactly the same codes and have the same address - which is why training a receiver with one remote, causes the other to be picked up as well.Whilst there are custom solutions, many remotes use PT2264 or equivalent encoders. These have an address that is set by connecting pins high (V+) low (GND) or not connected (High Z). If you can open up the remotes you might be able to see a row of pins with PCB traces running along side. Most remotes like this, you can set the address with solder bridges.Maybe open up one of the transmitters, and take a photo

author: downloaders
author_rank: Contributor
timestamp: June 21, 2018, 02:37:58 pm
content: I would think they have slightly different codes, because now one receiver just works with one remote. But I could be wrong.Here is the photo