Bluetooth to Maestro

Hi i’m Perro and i’m new.
I’ve got a Mini Maestro 12-channel USB servo controller.
I have already used the program using the Pololu USB cable and up to far so good. Now I would use a bluetooth connection using the RN-41 Bluetooth Module Carrier. Can anyone help me because I do not know the connection to be operated without using any type of external microcontroller.


Hello, Perro,

You should be able to control your Maestro with an RN-41 by connecting it to the Maestro’s TTL serial interface and sending serial commands to the Maestro. However, you cannot configure the Maestro or upload scripts to it this way, since the Maestro Control Center only works with the native USB connection.

- Kevin

Hi, I m sriker from India(Hyderabad)

Thanks to “Mrs Amanda sou” for directing me before in maestro sripting.but now I have Another problem in using serial commands via Bluetooth(hc-05) to maestro.I own 18 servo maestro and have set it to 19200 fixed baud rate,CRC disabled with all the interfacing connections correctly. But I m getting error (red led glowing constantly)

May be I went wrong with the code ,please check the code below and guide me

Code : (I wrote this code to test serial command in maestro)

6000 0 servo
1000 delay

Sub right
8000 0 servo
1000 delay
6000 0 servo

Sub left
4000 0 servo
1000 delay
6000 0 servo

After all this I have sent the command (0xA7,0x00) to restart the script from first subroutine via Bluetooth module to maestro through Bluetooth terminal in android, but I m getting error please help me

Thank you,

Hi, Sriker.

I added code tags ([ code ] [ /code ] without spaces) to your post to make it easier to read; please use this method to post code in the future.

I do not see anything obviously wrong with your code. What error message are you getting? Can you try running your script through the Maestro Control Center to see if you get an error without anything else connected to your Maestro (besides the USB cable to your computer)?

I am not familiar with the HC-05 Bluetooth device you are using, but after a quick search, it looks like the Bluetooth module uses 3.3V logic. Since the Maestro is not guaranteed to see 3.3V as HIGH, you should use a logic level shifter (like this one) to convert the 3.3V signal to a 5V signal for the Maestro.

Can you tell us more about your system? (Pictures of your system showing all your connections would be nice.) What program are you using to send commands from your Android device to the Maestro? Can you verify that your Bluetooth module is using the same baud rate as your Maestro (19200)?

- Amanda

hi, mrs.amanda.

happy to see u again, i will remember that when i post any code further. you have asked me to run my script through Maestro Control Center i have done it already as my code refers,the controller executes the first loop(endlessly) and i m not getting any error message

sorry for not giving complete details about bluetooth module i m using hc-05 with ttl outputs as per my knowledge its i/o pins are configured for logic 5v high, please correct me if I m wrong.
i m using just a simple bluetooth terminal android app from my andriod phone

coming to my system connections i have connected maestro’s rx and tx pin to tx and rx pins of hc-05 respectively and powered both maestro and bluetooth module separately with 6v.
thank you for giving me the suggestion about bluetooth baud rate, after a little bit search on it i have realized that i should change my bluetooth default baud rate in AT command mode

after making all this changes i will run the script,if the problem repeats i may trouble u again and please,let me know the procedure to send serial commands to maestro through bluetooth terminal. As i m typing just (0xA7,0x00) in bluetooth terminal and sending to hc-05. Is it a right way to send the commands

thank u , mrs amanda your help means me a lot

Thank you for your kind words and for providing answers to each of my questions. I did a quick search for the “Bluetooth terminal” app that you mentioned and found this app on the Google Play website. It looks like there is a option to send hexadecimal values through the terminal. If you are using this app, you might try selecting that option. Also, you would need to de-select the “Append newline(\r\n)” option to avoid sending the wrong series of bytes.

If this is not the app you are using to send commands from your Android to the Maestro, let me know the app’s name verbatim or provide a link.

- Amanda