130-28176 Parallax Inc, 130-28176 Datasheet - Page 210

• Manufacturer Part Number: 130-28176
• Description: KIT PARTS PROCESS CONTROL
• Manufacturer: Parallax Inc

Specifications of 130-28176

• Accessory Type: Education Kit
• Product: Microcontroller Accessories
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• For Use With/related Products: Board of Education Full Kit
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Contains lead / RoHS non-compliant

Note the new resolution as shown in Figure 6-16 compared to previous tests shown in
Figure 6-4. Gaps between points are temperatures that were not sampled. Note that
temperature resolves to .196 °F/bit by observing the change in voltage.
Program Discussion
The
are used in calculations and in setting the ADC. Since the BASIC Stamp does not use
floating-point math (values with decimal points), the values are multiplied by 10 so that
0.5 is stored as 5, or tenths of a volt.
ReadSP
The PWM style of setting offset and span may not be 100% accurate but is adequate
for our testing.
Combined offset and span voltages used to set the upper voltage limit (Vspan + Voffset)
should be 3.5 V or less since the op-amp is only powered from 5 V.
DEBUG CR,"!READ [(txtADCoffset),*,10]",CR
DEBUGIN DEC V_Offset
subroutine reads the values of offset and span from StampPlot. These values
Offset values below 0.5 V should be avoided for better accuracy.
Figure 6-16
ADC Measurement
0 to 500 °F and
70 to 120 °F