When designing microcontroller-based circuits, one of the tools available is a project development unit. This allows the software and hardware parts of the design to be tested in a real time environment but without the high cost of designing and building actual prototype systems.
Changes to both the software and hardware can easily be implemented without the need to produce a new prototype every time a change is required.
Development systems are available for most microprocessor/microcontroller systems. The development system described here has been squarely aimed at one of the more popular micros available today: the PICAXE range.
Very few people involved in the electronics industry – and especially SILICON CHIP readers – would not have heard of the PICAXE. There are now many different versions of the PICAXE, ranging in capabilities from 8-pin chips with limited memory space right up to powerful 40-pin fire-breathers!
Here's the Oatley Electronics
Project Development Board before being populated. You’d normally only have on board the components needed for the particular project, not everything as shown in the photo at left. Note that the white screen-printed overlay is a little misleading, in that links are shown between the prototyping area pads for the ZIF and 14-pin DIL sockets. If you want links, you have to put them in yourself!
And this month a brand new PICAXE chip, the 18M2 goes on sale, offering sensational performance and features (see SILICON CHIP June 2010 issue, page 44).
The development system described here will allow hardware/software debugging for over 90% of the chips in the PICAXE range.
As clever as micros are these days, they all suffer from one problem: they will always do exactly what you tell themto do. Unfortunately that is, especially in the early days of development, not exactly what you want it to do.
There would not be a programmer in the world who has never needed to debug the software they have written.
(Debugging is a term we use to describe the process of developing the software to allow completely problem-free operation ie, getting rid of the “bugs”.)
With this system you can assemble the hardware part of the design on a breadboard using the on-board IC sockets and then, using flying wires, connect the other components in the design to the chip.