Operation
6
SLYU048 – July 2018
Copyright © 2018, Texas Instruments Incorporated
DRV5055-ANGLE-EVM
2.1
Calibration Procedure
The calibration procedure is invoked each time the EVM is powered on. The calibration procedure can
also be started from the normal operating mode with a long-press (> 2 s) of the push-button switch.
shows the bottom silkscreen layer of the PCB. The PCB includes a quick lookup guide to the
calibration procedure, as detailed in the following steps.
1. With the board powered on, the instruction
SEL
is displayed on the LCD. Use the push-button switch to
cycle through the various, supported dual- and single-sensor configurations. To select a particular
configuration, hold down the push-button switch for at least two seconds (long-press).
2. Next, the instruction
SPIn
appears on the display. Spin the pointer around in any direction and
complete at least two full revolutions. The system automatically transitions to the next step when the
required information (that is, peak values of the sensor output voltages) has been stored.
3. If a single-sensor configuration was selected in Step 1, then at this point, the EVM enters the normal
operating mode. Otherwise, the
CP.
instruction is displayed.
CP
stands for
Calibration Points
and
represents the number of line segments used to approximate the nonlinear shaft angle-to-estimated-
angle transfer function. Up to 36 points are supported. Rotate the pointer clockwise to increase the
number of calibration points or counterclockwise to decrease the number of calibration points. A short
press (< 1 s) of the push-button stores the desired value.
4. The last step of the calibration procedure is to identify the positions on the compass corresponding to
the calibration points. For each calibration point that appears on the display, rotate the pointer to the
corresponding position on the compass, and press the push-button to store.
Figure 2. Calibration Guide on Bottom Silkscreen for Quick Lookup
