February 8, 2010
The board was populated successfully and most of the functional features of the board have turned out to be successful. I am yet to test one of the two voltage comparators available on the board.
The main features of the board include:
- PIC16F877A platform
- L293D module ( Can drive 2 geared DC motors or 1 stepper motor)
- ULN 2003A module for stepper motors
- Voltage comparator circuit for LDR based sensor module
- Voltage comparator circuit for IR LED – photodiode based sensor modules
- Analog Inputs
- Seven Segment Display * 4nos
- RS232 port
- LED outputs to test the comparators/voltage sensors
- 8 LEDs to test the outputs of the individual pins of the controller
- Plug and play option — Can test it with simple connecting wires across any pin of the microcontroller
- Power supply pins to power other add-on boards
Looking foward for your comments!
February 4, 2010
It had been a long time since the development board was manufactured. I was able to test some of the features of the board. I am done with the H bridge, RS232 communication and the A/D conversion. All were successful.
I realised the importance of input filters only when I blew up the microcontroller by connecting the 12V DC motor to the power supply that is not provided with input filters!
I tried pulse width modulation with my board and I have included a video that shows the motor running at slow speed in opposite directions.
Interaction of the PIC with the PC using MikroC routines
The MikroC routines for the PIC microcontroller were handy to test my board. In the picture, I was able to send a data to my PIC and echo it back to the PC!
I am yet to program the correct sequence for energising the sequence of the stepper motor coils.