27220 Parallax Inc, 27220 Datasheet - Page 169

• Manufacturer Part Number: 27220
• Description: BOOK STAMPWORKS
• Manufacturer: Parallax Inc

Specifications of 27220

• Accessory Type: Booklet
• Product: Microcontroller Accessories
• Lead Free Status / RoHS Status: Not applicable / Not applicable
• For Use With/related Products: StampWorks
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Not applicable / Not applicable

Moving Forward · Page 159
A neat trick with DEBUG is used to display the variable, mVolts.
The DIG 3
operation prints the whole volts and the DEC3 modifier prints the fractional volts
(rightmost three digits).
Reconnect the circuit as shown below and rerun the program.
Now use a multimeter to measure the voltage between pins 2 and 3 of the ADC0831.
Note that when the voltage on pin 3 is higher than pin 2, the output will be zero.
Taking It Further
As stated earlier, the voltage-per-bit for the ADC output is determined by the voltage
applied to Vref. Reconnect the circuit as shown below, and set the voltage on the
Vref pin to 2.55 volts (confirm with a multimeter).