Microchip Technology Humidity Sensor PICtail User Manual page 22

Humidity Sensor PICtail™ Demo Board User's Guide
4.2.2
Configure the Humidity Sensor PICtail™ Demo Board as follows:
1. Start with the configuration in Section 3.2.
2. Connect the shunt to jumpers JP1 – JP3 according to the modified measurement
resolutions and capacitance values desired; see Table 4-1.
TABLE 4-1:
Jumper
Selected
4.2.3
The capacitance.exe PC program displays measured capacitance values assuming
the Humidity Sensor PICtail™ Demo Board has not been modified. To correct the dis-
played values, move the displayed decimal point to the left two places (e.g., 321.0 pF is
actually 3.210 pF).
Note:
The RH numbers make no sense for measurements produced by the modified board;
they are based on another circuit configuration (see Section 3.2).
DS51594A-page 18
Modified Configuration
JUMPER SELECTION – MODIFIED CIRCUIT
Measurement Resolution
(pF / count)
JP1
JP2
JP3
Interpreting the Output from the Humidity Sensor PC Program
The decimal point must be moved two places to the left by the user for the
modified circuit.
0.001 0.6 pF to 65 pF
0.01 6 pF to 650 pF
0.1 60 pF to 6.5 nF
R
INT
C Range
SEN
(Ω)
6.65 M
665 k
66.5 k
© 2005 Microchip Technology Inc.