MPR03X

Sensors

12

Freescale Semiconductor

5

Output Mechanisms

5.1

Introduction

The MPR03X has three outputs: the touch status, values from the second level filter (Section 8.3), and the calibrated baseline

values. The application can either use the touch status or a combination of second level filter data with the baseline data to

determine when a touch occurs.

5.2

Touch Status

Each Electrode has an associated single bit that denotes whether or not the pad is currently touched. This output is generated

using the touch threshold and release threshold registers to determine when a pad is considered touched or untouched.

Configuration of this system is discussed in Section 9.

5.2.1

Touch Status Register

The Touch Pad Status Register is a read only register for determining the current status of the touch pad. The I2C slave address

of the Touch Pad Status Register is 0x00.

Figure 17. Touch Status Register

7

6

543210

R

OCF

0

0

0

0

E2S

E1S

E0S

W

Reset:

0

0

000000

= Unimplemented

Table 6. Touch Pad Status Register Field Descriptions

Field

Description

7

OCF

Over Current Flag – The Over Current Flag shows when too much current is on the REXT

pin. If it is set all other status flags and registers are cleared and the device is set to Stop

mode. When OCF is set, the MPR03X cannot be put back into a Run mode.

0 – Current is within limits.

1 – Current is above limits. Writing a 1 to this field will clear the OCF.

2

E2S

Electrode 2 Status – The Electrode 2 Status bit shows touched or not touched.

0 – Not Touched

1 – Touched

1

E1S

Electrode 1 Status – The Electrode 1 Status bit shows touched or not touched.

0 – Not Touched

1 – Touched

0

E0S

Electrode 0 Status – The Electrode 0 Status bit shows touched or not touched.

0 – Not Touched

1 – Touched