Think Create | Deqing Sun

Dandelion Bluetooth IO interface

by on May.25, 2011, under My gadgets

Dandelion is a project inspired by Gainer. It proves a simple solution to interact between the physical world and the digital world. When connecting the board to a computer, it acts as a serial port on the computer. That makes it easy to be manipulated by any program language. Then various sensors or actuators can be connected to its 10 digital IO ports and 2 analog input ports. All commands and data are sent in ASCII forms and those commands are user-friendly. Most important, it connects via Bluetooth. This can save a USB port and communicate in distance.

The board is breadboard compatible and can leave 2 rows of holes on each side for other usage. The Dandelion has an ultra low drop 200mA regulator so it can be powered by either a Li-cell or 5V supply. Besides, it may also act as an Arduino serial downloader with future firmware.

The Bluetooth module is originally designed for replacing the serial cable. So it is possible to replace the USB to UART chip on the original Gainer. But in fact the CSR chip is much more powerful than regular 8-bit chips; I customized the firmware by Bluelab to handle the analysis of the UART stream. So no external chip is needed. (Those chips for power management and level shifting may still be needed. :P)

Each command ends with a "*" or white space.

    format: ?

    format: Q

analog input all:
    format: I

analog input, continuous mode:
    format: i	

exit continuous mode:
    format: E

analog input from a specific pin:
    format: I%X
    example: I0
              |-- get analog value from channel 0

digital output all: (Only output pins will be affected)
    format: D%04X
    example: D0003
                 |- 0b00000011 set Channel 0 and Channel 1 high and others low

digital output setting to a specific pin:
    format: H%X   or   L%X
    example: H1
             ||-- digital channel 1
             |--- set that pin high

digital input setting to a specific pin:
    format: h%X   or   l%X
    example: l1
             ||-- digital channel 1
             |--- set that pin pull down

digital input all:
    format: R

digital input, continuous mode:
    format: r	

change sample interval:
    format: M%04X	
    example: M03E8
                 set interval to 1000ms

5 Comments for this entry

  • lee

    It looks great! You are super man!
    I also have this CSR bluetooth module, but I can only communicate use default firmware which transmit RS232 data transparently. How do you modify the firmware and use extra resources from CSR chip? It is appreciated if you can share the informations,thanks in advance.

  • seer

    Google “BlueLab”. I used 4.0.1 version. And burn the firmware and settings with parallel port.
    Be aware using it’s IDE without authorization may be illegal in your region.

  • Able Roberts

    Hi, i am looking for a bluetooth interface to transmit several I.O. signals(two ways), and also transmit a 0-5v variable signal(X 8 signals).Can your devise do this or can you reccomend something.

    looking forward to your response.

  • seer

    Hi Able. I think you may use a serial module and a micro controller to finish your task. As far as I know, no device can do that without modification and configuration.

  • john

    Hi, are you offering this board for sale?. If so, I would be interested in pricing.

    thank you


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