BY THOMAS KIBALO
IMPLEMENTING A
DATA LOGGER WITH
THE 16-BIT MICRO
EXPERIMENTER
Previous Nuts & Volts articles have presented a series of demos with an
overview of the 16-bit Micro Experimenter (Experimenter for short), its
hardware features and C libraries for LCD displays, pushbuttons, and
EEPROM and ADC operation. Now it’s time to roll up our sleeves and put
together a real working application. This article will use what we’ve learned
so far to build a stand-alone data logging application using the Experimenter.
Adata logger is very useful in experiments where long- term logging of time stamped data is needed.
Imagine collecting and storing temperature readings
throughout your house every 10 minutes over a four week
period; understanding heating and/or cooling efficiencies;
or measuring the voltage output from a solar collector
every hour over six months to identify the best placement.
A data logger can help make all this happen. In the course
of this article, we are going to introduce two more libraries
for the Experimenter: the Real Time Clock Calendar
(RTCC) and the Serial Port. They will be used with what
we have learned so far to build the data logger. As stated
in previous articles, all software will be kept to a general
level of understanding using straightforward functional
calls. However, some basic familiarity with C language
syntax will be required. For starters, let’s look at the basic
capabilities of the data logger that we will be building
Data Logger Description
Figure 1 shows a notional data logging block diagram
side by side with the actual Experimenter. We have the
LCD configured for menus to allow the user to operate
the data logger using pushbuttons. The RTCC (or clock) is
used to set data and time of data capture, as well as rate
of capture. The EPPROM (a full 32K x 8 byte non-volatile
■ FIGURE 1. Data
Logger Hardware
and Block Diagram.
28
June 2010