Microchip Technology MCP3421DM-WS ユーザーズマニュアル
MCP3421 Weight Scale Demo Board User’s Guide
DS51918A-page 16
2010 Microchip Technology Inc.
3.3
WEIGHT SCALE CALIBRATION
The MCP3421 Weight Scale Demo Board requires a two points calibration: one at 0g,
to remove the weight scale offset, and another at a known point, for gain calibration.
to remove the weight scale offset, and another at a known point, for gain calibration.
To perform the complete weight scale calibration the user must follow the next steps:
1.
Connect the weight scale to the PC and run the software.
2.
Press
S3 button to select the desired option (xPGA, xGLo or xGHi).
3.
Press
S4 to remove the offset. The weight indication does not reach 0 in all
cases. This is a normal behavior, since calibration is not completed at this step.
4.
Place a known weight on the scale’s platform.
5.
Write the weight value in the “Calibration Weight (g)” field on the GUI.
6.
Press
Calibrate button from the GUI, or F4 on the keyboard. This last step will
perform the gain calibration.
The offset calibration may be required more often than the gain calibration, for precision
reasons. Once the complete weight scale calibration done, the offset calibration can be
performed at any time, by pressing
reasons. Once the complete weight scale calibration done, the offset calibration can be
performed at any time, by pressing
S4.
It is important to perform complete calibrations for all six signal conditioning options.
The calibration constants are being stored in the MCU EEPROM.
The calibration constants are being stored in the MCU EEPROM.
FIGURE 3-2:
MCP3421 Weight Scale Demo Board Software – Calibration mode.