Hi!
I’m trying to send commands to the RN-41 bluetooth module from my PC, using HyperTerminal. I type in $$$, but I don’t receive any response. The expected response is CMD. Does anyone know what the problem might be?
I was careful to set the settings to baud rate 115200, 8 bits, no parity, 1 stop bit and hardware flow control. The com ports aren’t labeled on my computer, so I tried both com1 and com2.
I’ve started considering doing remote configuration using bluetooth, but I’m not sure how?
Hi,
I’m not sure whether this applies to RN-41 or not. If you look at Roving Networks user manual for the WiFi modules, they state that they have problem getting Hyper Terminal to work with their products and recommend TeraTerm instead. I found this on page 7 of their user manual for their WiFi modules. Might work a try. 
Thanks for answering, but I actually tried TeraTerm with the remote BT configuration. I could tell the module was connected, because the light stopped blinking, but it still wasn’t responding to $$$. Something surprised me with the remote configuration, the bluetooth module was considered two serial ports. To get a connection I needed to connect to both com10 and com11 using TeraTerm. Is that normal?
HI,
I think i am face same problem with you. I am using RN41 as well. My problem is after i connected the bluetooth with my pc (mean the LED on RN41 change from red to green), i not able to sent any output. It such as not respone me at all.
May i know you are you already solve your problem??If yes, may i know how to you solve it??
Really hope you can help me. Thanks a lot…
I’m fairly certain that the default for that module is 19,200 baud, and command mode must be entered within 60 seconds of powerup.
In addition, I think there is a 500mS ‘guard time’ before and after the $$$ to get into command mode, this is why you have to select “No extra character” on your term. I.E. Do not send CR or LF when sending the $$$
Sorry for that, but i not really get what your mean.
You mean that RN-41 not use 115200 baud?? is 19200 baud??
and May i know what is command mode you mean??
senting command??
really sorry for that. and really thanks for your reply…
Look carefully at the data sheet for your exact device, some devices are 115,200 baud by default, some are 19,200 some (Like their WiFly module) are even 9600 baud.
Command Mode.
I think what’s not obvious to people is that as far as the module is concerned, data is data. As such, it has to have SOME way to tell if the user wants to give it commands or send data. To that end, all of the devices have a “Command Mode” that you can get into which will turn off the module’s data mode and make it sit there quietly waiting for you to give it commands. The catch is that you have to be able to enter Command Mode while the module thinks that data should be being sent. As such, the command to get into Command Mode cannot be something simple like $$$ with no special timing constraints. Look at that, if that were the command to go into Command Mode, it would have done so right there… while receiving this post.
To get into command mode, send $$$ all by itself. No no other characters for at least 500 ms before or after the $$$.
To do this with the Arduino IDE, select “No line ending” in the selector at the bottom right, then enter $$$ and press return. The module should send back AOK
If it sends back nothing. It’s probably hooked up wrong. It it sends back garbage, the baud rate is wrong.
Hi, thanks for reply.
But i still stop in some where , hope you can help me. After I sent “$$$” and received a feedback CMD i can’t continue anymore. The device didn’t respone me any other command or reply “!” in somethings. May I know what wrong I make??and What i should do??
Once in Command Mode, then you have to send a CR after each command. The module is probably waiting for a CR to know when to process the command.
$$$ with no CR to get into Command Mode.
Command with CR once in Command Mode.
It mean that, after i sent $$$
Then i sent the command i want?such as " K" then sent command CR again??
summary
MSComm1.Output = “$$$” (Received CMD back)
MSComm1.Output = “K”
MSComm1.Output = “CR”
is it??
But i such as still not able to do it.Sorry for that and sorry for my poor english.
Really thanks for your help.
By CR I don’t mean literally the letters C and R. I mean Carriage Return. Pressing the Enter key while the IDE’s monitor is set to “Carriage Return” will append a Carriage return to the command and send it.