This page describes a simple controller board with relays and a MOSFET for motor speed control.
This board is easily constructed using salvaged parts.
Controller Description
Basic Stamp Port Assignments
Schematic
Board Layout
Photos
Parts List
Test Program
This controller board was constructed with primarily salvaged parts. A few items were purchased, such as
the perf board for the circuit, and the MOSFET for the motor speed control. The Controller board has three relays,
two of which are connected in such a manner as to provide Forward and Reverse control for the MOSFET output. These
two relays are connected in an H bridge. The third relay is used as a general purpose output, and in the case of
LEGO control could be used as a Steering output. The controller board also has a 555 timer used to provide and input
to the Stamp from and IR sensor. The IR sensor was salvaged from an old VCR, and its output is fed to the 555 timer.
The timer is wired as a "missing pulse detector", and provides a low output when there is no IR signal. Connections
for a serial output to a PC have been provided. The I/O assignments for the Basic Stamp are given below.
PB0 - Serial input from PC
PB1 - Serial output to PC
PB2 - Motor speed PWM to MOSFET
PB3 - Forward relay output
PB4 - Reverse relay output
PB5 - General purpose relay
PB6 - Spare input
PB7 - 555 timer missing pulse input
Controller
Controller with IR Sensor Module
The following is a list of the required parts:
This is a simple program to control the speed of a motor connected to
the controller board.
Basic Stamp Port Assignments
Schematic
Board Layout
Photos
Parts List
Test Program
Controller Description
This controller board was constructed with primarily salvaged parts. A few items were purchased, such as
the perf board for the circuit, and the MOSFET for the motor speed control. The Controller board has three relays,
two of which are connected in such a manner as to provide Forward and Reverse control for the MOSFET output. These
two relays are connected in an H bridge. The third relay is used as a general purpose output, and in the case of
LEGO control could be used as a Steering output. The controller board also has a 555 timer used to provide and input
to the Stamp from and IR sensor. The IR sensor was salvaged from an old VCR, and its output is fed to the 555 timer.
The timer is wired as a "missing pulse detector", and provides a low output when there is no IR signal. Connections
for a serial output to a PC have been provided. The I/O assignments for the Basic Stamp are given below.
Basic Stamp Port Assignments
PB0 - Serial input from PC
PB1 - Serial output to PC
PB2 - Motor speed PWM to MOSFET
PB3 - Forward relay output
PB4 - Reverse relay output
PB5 - General purpose relay
PB6 - Spare input
PB7 - 555 timer missing pulse input
Schematic
Board Layout
Controller Photos
Parts List
The following is a list of the required parts:
- 555 timer
ULN2004A driver
7805 regulator
LEDs
3 relays
1 IR510 MOS Fet
470 ohm resistors
8.2 k ohm resistors
10 k ohm potentiometer
2 heatsinks
perfboard
misc. connectors
Test Program
This is a simple program to control the speed of a motor connected to
the controller board.
