Plug-in Hardware Modules

These are the additional hardware circuits that can be connected to PMDK main board for added functionality.

Test Circuit for Digital Output and Analog Input
    This PCB is designed to plug in to Port C and the last two channels of the Analog Inputs (Port A). The port C pins will get connected to LEDs. A potentiometer will provide input to the Seventh Analog Input (Port A, Bit 7)

Operational Amplifiers
    This plug-in board provides four channels of Op-amps. This board takes 5V supply from the main board and can be plugged to the connector on the left bottom side.

H-bridge circuit for DC Motor Control

    This Circuit can be plugged to I/O ports on the main board to control the H-bridge inputs. Three LSBs are used for one bridge and three MSBs for the second bridge, 4th and 5th bits are unused. The supply to the H-bridge should be given through a 2pin connector. The single sided PCB require two jumper wires to complete the circuit.

  This circuit has five LED-Phototransistor pairs. The LEDs can be switched ON or OFF and the output of the phototransistor can be measured using the analog inputs.

40 KHz Piezo Tranceiver
    The piezo board is powered by the 9V DC input that can be tapped from the main circuit. Two I/O pins go from the main board to this circuit, one to send the signal to the transmitter piezo and the other one to receive the amplified signal from the receiver. This module can be programmed to measure distance to some object in front of the tranceiver  using the reflection of sound.

Stepper Motor Driver
    Output of four I/O pins are amplfied this board and their output is provided in an open collector configuration. With software this can be used to drive the 4 coils of a stepper motor, or driving some relay coils. Power to this board is to be provided on a separate two pin connector.

RS232  Level shifter
    The ATmega16 micro-controller supports RS232 communication ports, through the RxD and TxD pins. On the circuit board we have taken these lines to a 4 pin connector along with ground and 5V supply. The Level Shifter module converts the -9V to +9V level signals from the PC Serial ports to the 0 to 5V signals on the micro-controller side. This can be plugged to the main board.