By the CHIPAXE TEAM
Figure 1. CHIPAXE Breadboard
When our CHIPAXE programming system was first introduced in the
November Nuts & Volts “Getting Started with PICs” column, we were
surprised by the great email response we received. Frankly, we were caught
off guard by the large amount of interest. After all, CHIPAXE is just a simple
concept conceived one night by a few friends during a round of beers. The
original concept was to create an open source, low cost way to help people
get started programming. What we found was you can’t have a programming
setup without offering various applications for someone to build, and none is
more popular it seems than examples of how to work with sensors.
In this article, we’ll attempt to describe a few extremely simple and low cost sensor applications that can be used for robotics or any electronic application. The logic board
used for the projects is our own CHIPAXE Breadboard
Starter Kit which has an eight-pin PIC12F683
microcontroller (Figure 1). The CHIPAXE system uses the
sample version of the PICBASIC PRO compiler so the
programming is simple for the beginner.
In this project, we’ll use the analog-to-digital converter
(ADC) in the PIC12F683 to read a CDS cell which changes
resistance as the light around it changes. A simple eight-bit
resolution result will work perfectly. As the light changes,
the ADC value will be tested. If it’s a high value (high
resistance), then it’s dark out and a single LED lights up.
Figure 2 shows the final setup.
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