DSD TECH HC-05 Bluetooth Serial Pass-through Module Wireless Serial Communication with Button for Arduino

Hi,I bought two of these to allow me to communicate between 2 arduinos. I had googled a little and it seemed simple enough from the examples I had seen, but once I got the chips I discovered none of the examples I found on-line worked. That's where the support desk from DSD came in, these guys were great, I explained what I wanted to do and they helped me every step of the way, I'm not sure I would have gotten them working without the support desk's help.So if anyone wants to send data between two arduinos using these blue tooth chips here are the steps I followedStep 1 To wire up the blue tooth to the arduinos follow the instructions on the following site, I also found arduino libraries help which controlled the serial communication ( I could not get the normal Tx Rx pins to work)http://www.martyncurrey.com/arduino-to-arduino-by-bluetooth/However the bluetooth commands listed on this site did not work for me, that is where DSD came to my rescue.Step 2 To enter the AT command mode (where you define setting on the chip) press the button on the right hand side of the chip just above the pin as you are powering the chip on, if the chip enters command mode the led will flash slowly.Step 3 Once in command mode select one chip to be the slave and one to be masterAT+ROLE=0 (Slave mode)AT+ROLE=1 (Master mode)Step 4 Set names for both chipsAT+NAME= nameAT+NAME? should give you the name back but didn't work for me, so instead I confirmed the name using an android phone ( note devices in master mode will not show up in a scan)Step 5 Set passwordThe default is 1234 and you could leave it at that if you really want but probably better to change itAT+PSWD=passwordAT+PSWD? will return the passwordMake sure to set the same password on both devicesStep 6 find device addressAT+ADDR?Record the value for both master and slaveStep 7 on both devices do the followingAT+CMODE=0and on the masterAT+BIND = slave addresson the slaveAT+BIND = master addressStep 8 both cycle both devices do not press the button to put them in command modeThey should now connect to each other the led will start to flash rapidly this is them in pairing mode and once they pair the led will do a double flash once every couple of seconds.On final thing I had to set the BTserial on the arduinos to 38400 not 9600.So that's it, the delivery time was good, the chips work and the helpdesk coudn't have been better, I would buy more stuff from DSD.

This is the third purchase from DSD Tech and have all been reliable and good build quality. The very excellent product setup and description from Mel Cushnahan was very helpful. The only thing I would add is I spent hours trying to get 2 HC-05's to communicate together. I eventually found that some websites say connect the EN pin to 3.3v, which I had done. After reading the data sheet I found that this puts the HC-05 into AT mode and is only required if the module does not have a AT mode button, which the DSD Tech has, so leave the EN pin unconnected. Apart from that, if you follow Mel Cushnahan instructions, when you cycle the power both HC-0's blink rapid whilst pairing and then a double blink every few seconds once paired.

Works fine but online documentation is not great.This took me several hours to work out, but when trying to put the module in AT mode for programming use the following connections:RX (HC-05) -> 11 (Arduino MEGA) (NOT the RX and TX pins on the MEGA as the code doesn't work with them)TX -> 10VCC ->5VGND -> GNDEN -> 3.3Vwithout any code at all this should put your bluetooth model into at mode (LED flashing with 2 second interval)Now upload this code, which several other people have posted already (you need to disconnect the RX and TX pins during the upload otherwise the serial port will report busy and give you an error):#include <SoftwareSerial.h>const int txPin = 11;const int rxPin = 10;SoftwareSerial BTSerial(rxPin, txPin); // RX, TXvoid setup() {Serial.begin(9600);Serial.println("Enter AT commands:");BTSerial.begin(38400);}void loop() {if (BTSerial.available()){Serial.write(BTSerial.read());}if (Serial.available()){BTSerial.write(Serial.read());}}The key issue that I was have is that the SoftwareSerial library only supports certain pins on the Arduino MEGA, which - counterintuitively - do not include most of the RX and TX pins.Finally open your serial monitor in the Arduino IDE, with a baud rate of 9600 and the other dropdown menu to BOTH NL & CR.Good luck and hopefully this will save you some time.

Good quality.I previously bought a set of six from another seller which although I was able to configure with different AT commands, would not transmit data.The HC-05 from DSD Tech was easy to configure and connection/pairing was instant and superb.It even came with an instructional leaflet.Each of the modules is in a protective plastic jacket.Nice product.

I've bought 4 of these now. I'he used them mainly for connecting Arduinos and TTL serial devices to my Android tablet running a BT serial terminal. How convenient! If you want to communicate from a 3.3v system to a 5v system via serial comms, this is a great way to avoid level converters. Keep a couple in the spares box...

I managed to get AT Mode to work once, but can't seem to get back onto it again.

Came very well packaged. Board came with a plastic cover to protect it from dust and what not. Tested it today finally and glad to say it worked perfectly with the arduino and I was able to connect it to my phone.