Old Hobby in New Age

After my (mis)adventure with ordering a micro controllers in QFN pack, I decided to play it safe. Meaning take the new things in baby steps. To start in the uncharted territory ordered a development board and programmer from the “source” – Microchip. For the beginner PICKIT2 with LPC development board looks safe one to handle.

LPC+Pickit is good. One can program it without taking it out from the circuit. It has nice LEDs switch and potentiometer that suffice many applications. But soon I realized the full meaning of LPC – L is for limited. One needs more space to connect various things with the LPC. So came a bread board.

 Now, connecting LPC with bread board is not a easy task. Connecting 14 sets of wire is a chore. A bridge connector makes the 14 wire to one connection.

 Concept of modularity gets carried further into break out boards. Here is an array that I got myself end of a couple weeks. From top left is a DIP switch with extra long connector to get firm connection on breadboard, a set of eight pins shorted for getting Vcc to DIP switch, a power supply from battery eliminator, I could not find a resistor block in the local store so made one, next is a LED array to check the states of a port, next is to check 1 bit – green and red, then a piezo buzzer from a discarded clock to make some noise and a set of four LEDs to check a nibble size.

After all the LEDs it is time for some real output – here is a 4 segment LED display. I am using here a CD4511 – BCD to 7Segment decoder/latch/driver. This IC reduces the no of pin required quite a bit, then I use a program to multiplex the display.

Now, connecting the LPC with this board requires some 10 set of wire. This is made simple with another bridge connector. For protection, I encased all the wires in a good dose of glue. Now it will develop any loose connection with multiple handling.
Here is a small timer on my LPC prototype. Requires 3 connections.

 Working with 4511 requires less pin from microcontroller but it has limitation. One can only display numbers with it. Here is another display that is totally software driven and multiplexed. This is made on a stripboard. Connections from LED pins are taken out below the LED resulting in a rather neat appearance.

Next step is a LCD display. LCD is good companion to uCs. It does not need to be refreshed continously, has more number of character and gives better look and feel.

I have put header pins on the LCD display for quick connection to breadboard. But I realized, there is something wrong with this display. Checking LCD display is rather difficult. The display has a uC on its own

 and requires complex sequence of instruction to show anything. There is a nice blog by Suhas [http://iamsuhasm.wordpress.com/tutsproj/using-lcds/] that describes how to check a LCD. COncept is nice, but I felt the PCB can be improved. Some more search on the net got me a nice CAD package – VCAD that supports strip board layout. A weekend on VCAD, I could get the circuit on a 16×16 piece of board. Here is the layout. that you can also use in some place.

While making the board, I found some used components and modified the layout a little bit to use those old rusty pieces.

Result is slightly different, but still needs less footprint and desk space and goes into breadboard without any other additional piece of wire.