Download Gertboard User Manual

Gertboard Overview
Raspi
SPI
D
in
A
MCP4802
L6203
D
I/O
1k
3x
1k
A
Motor
controller
UART
I/O
PWM
Micro controller
12x
ATmega
74xx244
out
SPI/dbg
MCP3002
open collector (6x)
strapping area
ULN2803a
Fig. 1: The principle, high level diagram of the Gertboard. In this view it is possible to see how
flexible Gertboard is, by being able to connect various parts of the board together.
Above is a principle diagram1 of the Gertboard. Each circle in the diagram represents a header pin.
These headers give you access to a wide range of control combinations. As you begin experimenting
with the board, you will probably use the strapping area to connect various components on the
Gertboard to the Raspberry Pi. This flexibility even allows you, for example, to connect the motor
controller input pins to the Atmel ATmega device (an AVR microcontroller). The ATmega device has
a separate 6-pin header, which allows it to be programmed by the Raspberry Pi using the (Serial
Peripheral Interface) SPI bus.
The major building blocks are:
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•
•
•
•
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12x buffered I/O
3x push buttons
6x open collector drivers (50V, 0.5A)
48V, 4A motor controller
28-pin dual in line ATmega microcontroller
2-channel 8/10/12 bit Digital to Analogue converter
2-channel 10 bit Analogue to Digital converter
Each of these building blocks has a section below.
1
A ‘principle diagram’ is a coarse overview of the most important parts of the system. It is not correct in all details. For that
you must look at the board schematics.
4