Freescale Semiconductor Evaluation Board MPR031/2 for 2- or 3-pad touch sensor controllers DEMOMPR031 DEMOMPR031 データシート

Sensors

12

Freescale Semiconductor

The MPR03X has three outputs: the touch status, values from the second level filter (

), 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.

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 

.

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

2

C slave address 

of the Touch Pad Status Register is 0x00.

7

6

5

4

3

2

1

0

R

OCF

0

0

0

0

E2S

E1S

E0S

W

Reset:

0

0

0

0

0

0

0

0

= Unimplemented

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