DSD TECH HM-10 Bluetooth 4.0 BLE iBeacon UART Module with 4PIN Base Board for Arduino UNO R3 Mega 2560 Nano

I am developing a system for measuring thermal conductivity in buildings, and need a means of communicating between a units on the exterior and interior of the building. My plan is to place the units either side of a window, so Bluetooth range should be adequate. The units will be battery powered, so power consumption is important, which attracts me to Bluetooth Low Energy.I bought 2 of these boards to evaluate, and here are my findings so far:Connecting to an HM-10 board using an Android phone is straightforward using BLE scanner.I next tried to connect to one of the boards using a terminal emulator (Putty) via a USB-Serial converter, the unit responded to AT with OK, but failed to recognise any AT commands. Conclude that Putty is inserting extra characters.I next tried the same thing using RealTerm, which worked fine.I then set up the second unit running in another terminal emulator window, so that I could get them to communicate.To do this one of the boards needs to be set to receive mode so I doAT+ROLE1AT+CO<AddressOfOtherDevice>This succeeds in getting the boards to communicate, so anything typed in one terminal window appears in the other, including AT commands, so its quite difficult to stop communication. You should be able to get break the connection by AT followed immediately by an AT command. Actually I am not telling the whole story as I had tried some other things first.The following sequence works reliably to connect:AT+RENEWAT+IMME1AT+ROLE1AT+CO<Address>send some stuffATAT+ROLE0AT+RENEWNext put the slave board to sleepAT_NOTI1 // To get a notification when the connect is made or dropped.AT+SLEEPThe master board can still connect.Next I put both boards to sleep.You need to wake one of the boards with a sequence of random characters until you see OK+WAKEThen you can connect as before.After your conversation is finished you can put both boards to sleep again.I have captured those findings in a console program which runs in master and slave modes on a PC connected to both boards, this reliably puts the boards to sleep, one wakes every few seconds, connects with the other, sends some messages and both boards go back to sleep.I haven't tested the communication range yet, but so far they work well after a bit of investigation/development.

Wanted this to replace HC-05s on an Arduino SoftwareSerial link in a Master/Slave set-up.Struggled to bind them at first as the firmware is not quite standard but the customer support is some of the best I've seen.Had instructions back for AT commands to use within a few minutes of requesting.

difficult to setup, not for the novice.

Worked straight out of the box. I'd already got an HC-06 working with a BT adaptor on my PC but needed the HM-10 so it could work with a BT serial app on my iPhone. It worked flawlessly. However, the app connected straight to it without any security check at all. I guess you can build that into you program but since it's not being used for anything requiring security I don't mind. I may look into proper pairing and security later if I need to.Would use again, in fact, I may have to since this one is going in a project.EDIT: Apparently it comes set to no PIN required. This can be easily changed.

I managed to set up the product in under 30 minutes with the app from the play store. So far everything works nice ! Very friendly contact as well. Keep up the good work ! :)

Got this to use for a Bluetooth setup for home automation and works great with a large range, also good for anyone starting out as simple to use.

Doesn't connect with mobile phone or any other Bluetooth/BLE apps other than DSD app.

Absolutely fantastic. If you have just upgraded to Android 8 (Oreo) these are genuine HM-10 modules that can be seen by BLE scanning applications. Highly recommend considering the amount of fakes on the current market for an excellent price. Excellent for any mobile application development (IOS or Android) and communicate well with other modules. Thanks guys, much appreciated.