Think Create | Deqing Sun

Dandelion introduction

by on Sep.21, 2011, under Uncategorized

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. Also it is an ideal platform to develop Android related gadgets.
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 auto-reset function.

Pin out:

Electrical characteristics:
Supply voltage: 3.6V~6V
Digital IO current: 4mA
Digital IO voltage 3.3V
Analog input range: 0~1.8V
Analog input resolution: 8bit (0~255)
Current consumption: less than 50mA
Current capability for peripheral circuit: less than 150mA

Watch the polarity of the power source.
The dandelion works on 3.3V. Do not to connect the IO ports to 5V directly.
When connecting power source on “+” pin. The 3.3V pin on the bottom can provide 3.3V power up to 150mA. Also you can power the dandelion with 3.3V power source connected on the bottom 3.3V pin. Do not use two power sources at the same time.
Notice the analog input range is 0~1.8V.
Avoid touching the board in working. The current on your finger caused by main power radiation may make it reset. The problem will be more severe if you use a poor quality wall plug power source. Using batteries will improve the situation greatly.

Led statues:

idle: waiting for connection. Will function as an IO interface on next connection

idle: waiting for connection. Will function as an Arduino downloader on next connection


sleep: Have been waiting for too long time. Not connectable or discoverable now. Using wake up button to become idle.

Command set:
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

Work as Arduino downloader on next connection: (transparent serial connection with auto-reset)
format: AU

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