Data Sheet

Schematic Capture
13
Relative humidity
A number of low cost silicon transducers with built-in signal conditioning or digital interfaces
have been used for measurement. This reduces the number of components to the minimum
required for dsPIC33 interfacing.
All measurements get periodically stored into a non-volatile, low power memory in row binary
format for later transfer to a host PC either by using a serial terminal or, more properly, a simple
program (not supplied with the project). For the purpose of this project a serial terminal is used.
The circuit is designed to work with a battery for relatively long period in an unattended
environment and, as such, a particular emphasis has been given to optimizing the power
consumption and consequently the battery life. The recorder will sleep most of the time and will
be woken up periodically only to accomplish the required recording operations.
Circuit Description
The following is a block diagram showing the behaviour and interaction of the circuit
components.
Block diagram of the dsPIC Data Reorder Design
We’ll cover the basics of the design construction as we progress through the tutorial but in order
to keep the focus on the practical aspects of using the software, design decisions and theory
will not be discussed in this document.