DSD TECH 12V Bluetooth Relay Module for Remote Control Switch Compatible with iPhone and Android 4.3...

Junk electronics from China. Will not connect via Bluetooth (error states: 'Couldn't pair with dsd tech because of an incorrect pin or passkey'). Tried clearing my Bluetooth cache and also reset all of those settings. They state their app is in Google Play, but it is not. The link on DSD's site is broken. You can download the app directly from their site, but I'm not going to put an app that is not certified by Google Play on my Android. Tried emailing tech support, but they don't exactly answer your question (most likely due to the language barrier). Not worth returning as shipping would be about half the cost of the product. I really don't understand how this product has favorable reviews. I didn't try it on an iPhone as I don't have one available.

I bought 2 of these bt relays, then later bought another 2. The first two I bought look basically identical. Of the second 2, one unit was in a box that had been reopened and re-sealed with packing tape. The re-sealed unit appears to have relatively worse soldering on it, some of the components on there crooked and there is flux all over the board. However the bluetooth transciever subboard on the re-sealed unit is indentical to the one on the earlier two units, but the sealed unit from my second purchase has a different looking subboard. Looking at the two units from my most recent purchase it looks like they have slightly different relays as well. A nice little board for building smart switches that don't require internet connectivity or apps, but the consistances in manufacture make me worry about switch mains voltage with them.

I'm going to order another one to see if I have a defective unit but I was able to run 12V power to it, then bought a 5V relay to power the board and was able to download and use the Iphone app. Unit powers up and can be connected and disconnected with the app, but I'm nothing is happening at the outputs. I get continuity at the 12V and 5V connections but not at the COM, NO and NC connections. I emailed their support a few days ago and have gotten zero response. I'd classify myself as an advanced beginner when it comes to electricity so it could be me, but it seems like everything is connected correctly. I'll order another one and see what happens.

Does what the description says it does. As others mentioned, the device has no security, so if that's important to your intended application, you should look elsewhere. I had trouble getting serial commands to work with another app, but that was because I neglected to send them as hex.

I love this 2 channel bluetooth relay board. I'm using it in a vehicle as I hate having switches mounted all over the dash. I used an add a fuse to power the board with a circuit that only has power when the key is on. That way someone cannot turn on the relays when the vehicle is parked. I use this board to control two 40 amp relays that power a light bar and electric cooling fans. I have the relay in a weather proof enclosure mounted under the hood. It's been through negative tempatures in winter and 110 degree summers and has not failed. Both my Android and my iPhone pair every time without any issue using the DSD Tech app. The board also has buttons to manually turn the relays on and off if my phones go down. I also have the 4 channel version in another vehicle and have had no issues with it. I'd highly recommend these DSD Tech bluetooth relays. They are amazing! I'll probably buy a couple more for projects around the house.