MPR121_10 FREESCALE [Freescale Semiconductor, Inc], MPR121_10 Datasheet - Page 41

• Manufacturer Part Number: MPR121_10
• Description: Proximity Capactive touch Senosr controller
• Manufacturer: FREESCALE [Freescale Semiconductor, Inc]

Table 41. Proximity Baseline Filter Registers 0x36~0x40 (Reset Default: all 0x00)
Sensors
Freescale Semiconductor
5.0
maximum half delta for rising/falling, the noise half delta for rising/falling/touched, the noise count limit for rising/falling/touched,
and filter delay for rising/falling/touched.
response on baseline rising (when hand takes away) and slowest response on baseline falling (when hand approaching). Refer
to Freescale application note AN3891 for detailed description on baseline system.
6.0
electrode to be properly set. This can be done in 3 ways:
to Freescale application note AN3889 for details of the Auto-Configuration function.
ELEPROX Max Half Delta Rising
ELEPROX Noise Half Delta Amount Rising
ELEPROX Noise Count Limit Rising
ELEPROX Filter Delay Limit Rising
ELEPROX Max Half Delta Falling
ELEPROX Noise Half Delta Amount Falling
ELEPROX Noise Count Limit Falling
ELEPROX Filter Delay Limit Falling
ELEPROX Noise Half Delta Amount Touched
ELEPROX Noise Count Limit Touched
ELEPROX Filter Delay Limit Touched
As with the touch detection, the proximity detection also dedicates register sets for baseline filter control. These include the
Same as touch sensing, the proximity sensing requires that the charging current and time for the 13th Proximity Detection
It’s recommended that Auto-Configuration is used for design efficiency if proximity sensing works properly in this way. Refer
1. Globally setting the AFE Configuration Register (0x5B) and Filter Configuration Register if recent current setting and time
2. Set by using Eleprox Electrode Current Register (0x6B) and Charge Time Register (0x72).
3. Using Auto-Configuration function to automatically set charge current and charge time for this 13th Proximity Detection
Proximity Baseline Filter Setting
Electrode Configuration for Proximity Sensing
setting is zero.
electrode.
Register Name
Table 41
shows an example setting for proximity sensing, the concept is to have quickest
Register Address
0x3C
0x3D
0x37
0x38
0x3A
0x3B
0x3E
0x3F
0x40
0x36
0x39
Example Setting
0xFF
0xFF
0xFF
0xFF
0x00
0x00
0x01
0x01
0x00
0x00
0x00
MPR121
41