Registration Number AT3405 Project…

                                Registration Number AT3405



Project Title: Papilion


Abstract

Papilion (Latin for ,,butterfly") aims to demonstrate the relative ease of use of ATMEL's
demo kit for the ATMEGA169, called "Butterfly".

The project uses the Butterfly as a control device for a simple two-wheeled, differential-
steered robot model.

Some of the various features of the kit (LCD, temperature and light sensor, joystick and piezo
element) are shown.
For propulsion two modified servos are used which have to be controlled by a special pulse
train. For this purpose two of the pins of the JTAG connector are used as control lines.
Initializing and driving of these lines is also demonstrated.

The programming is done in BASCOM-AVR by MCSELEC, a simple to use but feature-rich
basic dialect which is well suited for the beginner as well as the advanced user of
microcontrollers.

The short and simple program takes up about 15% of the device's flash ram space and can be
used as a template for the reader's own projects.

The program is transferred into the kit by using ATMEL's STK500 which is compatible with
BASCOM. Other means of in-circuit programming can of course be used just as well.

The hardware consists of the butterfly, a chassis which is made of aluminum, the two servo
motors and a battery holder (providing 6V), a servo power switch and a little board for
connecting the butterfly to the motors. Apart from some connectors which were soldered into
the butterfly's PCB (Port B, Port D and JTAG connectors) the kit was left intact and
unchanged.
                  Registration Number AT3405




Fig. 1: Robot "Papilion" with the ATMEL Butterfly and the STK500




              Fig.2: Flowchart of the Demo program
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Fig.3: Block Diagram of the project hardware




             Fig.4: Schematic
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Source Code:
'*************************************************
'
' Simple Butterfly demo
'
'*************************************************
'
'
' Butterfly functions and ports:
' ------------------------------
' Dataflash:
' PB0    SS
' PB1    SCK
' PB2    SI
' PB3    SO
'
' Joystick:
' PB4    Center
' PB6    A
' PB7    B
' PE2    C
' PE3    D
'
' Piezo Element:
' PB5    speaker
'
' Temperature sensor:
' PF0    NTC
'
' Voltage Input:
' PF1    Vinp
'
' Light sensor:
' PF2    LDR
'
' Serial port:
' PE0    RxD
' PE1    TxD
'
' free pins:
' PF4-7 from JTAG-interface: disable it!
'
' PD     used with the LCD, to use it disable LCD!
'
' ************************************************
'
'
'
'     Caution : don't forget to check:
'     - JTAG disabled (have a look at the fuse bits) ?
'     - correct setting for internal oscillator (no clock divide)?
'
'
' ------------------------------------------------