Apparatus and method for reducing average scan rate to detect a conductive object on a sensing device
A switch circuit and method is described. In one embodiment, the switch circuit is configured to couple each of a plurality of plurality of capacitive sense elements and a plurality of capacitance sensors in different modes. In a first mode, the switch circuit is configured to couple each of the plurality of capacitance sensors to a group of two or more of the plurality of capacitive sense elements. In a second mode, the switch circuit is configured to couple the plurality of capacitance sensors to individual ones of the two or more of the plurality of capacitive sense elements in one of the groups.
1. An apparatus comprising:
a processing device comprising a plurality of capacitance sensors and a plurality of pins; and
a switch circuit coupled to the processing device and to a plurality of capacitive sense elements coupled to the plurality of pins, wherein the processing device is to select a first capacitance sensor of the plurality of capacitance sensors to couple to a first group of two or more of the plurality of capacitive sense elements via the switch circuit in a first mode and to couple the first capacitance sensor to an individual one of the two or more of the plurality of capacitive sense elements in a second mode.
2. The apparatus of claim 1 , wherein the processing device is to select a second capacitance sensor of the plurality of capacitance sensors to couple to a second group of two or more additional of the plurality of capacitive sense elements via the switch circuit in the first mode and to couple the second capacitance sensor to another individual one of the two or more of the plurality of capacitive sense elements in the second mode.
3. The apparatus of claim 2 , wherein the switch circuit is configured to switch between the first mode and the second mode when a presence of a conductive object is detected in an area corresponding to one of the first or second groups in the first mode.
4. The apparatus of claim 2 , wherein the processing device is configured to control the switch circuit to couple the first capacitance sensor and second capacitance sensor to the plurality of capacitive sense elements in the first and second modes.
5. The apparatus of claim 2 , wherein:
the processing device is configured to perform a first scan to detect a presence of a conductive object while the switch circuit is in the first mode;
the processing device is configured to perform a second scan when the presence of the conductive object is detected in the first scan; and
the processing device is configured to not perform the second scan when the presence of the conductive object is not detected in the first scan.
6. The apparatus of claim 5 , wherein:
in the first scan, the processing device measures, using the first capacitance sensor, a first capacitance on the first group of the two or more capacitive sense elements coupled together;
in the first scan, the processing device measure, using the second capacitance sensor, a second capacitance on the second group of the two or more capacitive sense elements coupled together; and
in the second scan, the processing device measures, using at least one of the first capacitance sensor or the second capacitance sensor, a third capacitance on each individual one of the two or more capacitive sense elements of one of the first or second groups,
wherein the one group corresponds to a first area in which the presence of the conductive object is detected during the first scan, and
wherein the two or more of the plurality of capacitive sense elements in the one group are not coupled together in the second mode.
7. An apparatus comprising:
a processing device; and
a switch circuit comprising:
a plurality of inputs to couple to a plurality of capacitive sense elements, and
a plurality of outputs to couple to a plurality of capacitance sensors, wherein the switch circuit is configured to couple two or more of the plurality of inputs together in a first group and to couple the first group to one of the plurality of outputs in a first mode, wherein the switch circuit is configured to couple an individual one of the two or more of the plurality of inputs to the one of the plurality of outputs in a second mode.
8. The apparatus of claim 7 , wherein the switch circuit is configured to couple two or more additional ones of the plurality of inputs together in a second group and to couple the second group to another one of the plurality of outputs in the first mode, wherein the switch circuit is configured to couple another individual one of the two or more of the plurality of inputs to the other one of the plurality of outputs in the second mode.
9. The apparatus of claim 8 , wherein the switch circuit is configured to switch between the first mode and the second mode when a presence of a conductive object is detected in an area corresponding to one of the first or second groups in the first mode.
10. The apparatus of claim 8 , wherein the processing device is configured to control the switch circuit to couple the first capacitance sensor and second capacitance sensor to the plurality of capacitive sense elements in the first and second modes.
11. The apparatus of claim 8 , wherein:
the processing device is configured to perform a first scan to detect a presence of a conductive object while the switch circuit is in the first mode;
the processing device is configured to perform a second scan when the presence of the conductive object is detected in the first scan; and
the processing device is configured to not perform the second scan when the presence of the conductive object is not detected in the first scan.
12. The apparatus of claim 11 , wherein:
in the first scan, the processing device measures, using the first capacitance sensor, a first capacitance on the first group of the two or more capacitive sense elements coupled together;
in the first scan, the processing device measure, using the second capacitance sensor, a second capacitance on the second group of the two or more capacitive sense elements coupled together; and
in the second scan, the processing device measures, using at least one of the first capacitance sensor or the second capacitance sensor, a third capacitance on each individual one of the two or more capacitive sense elements of one of the first or second groups,
wherein the one group corresponds to a first area in which the presence of the conductive object is detected during the first scan, and
wherein the two or more of the plurality of capacitive sense elements in the one group are not coupled together in the second mode.
13. The apparatus of claim 7 , wherein the plurality of capacitive sense elements are arranged in a plurality of rows and in a plurality of columns, wherein the first group comprises two or more rows of the plurality of rows and the second group comprises two or more additional rows of the plurality of rows.
14. A system comprising:
a sensing panel comprising a plurality of capacitive sense elements;
a processing device coupled to the sensing panel via a plurality of pins coupled to the plurality of capacitive sense elements, wherein the processing device comprises a switch circuit, wherein the switch circuit comprises:
a plurality of inputs to couple to the plurality of capacitive sense elements; and
a plurality of outputs to couple to a plurality of capacitance sensors, wherein the switch circuit is configured to couple two or more of the plurality of inputs together in a first group and to couple the first group to one of the plurality of outputs in a first mode, wherein the switch circuit is configured to couple an individual one of the two or more of the plurality of inputs to the one of the plurality of outputs in a second mode.
15. The system of claim 14 , wherein the switch circuit is configured to couple two or more additional ones of the plurality of inputs together in a second group and to couple the second group to another one of the plurality of outputs in the first mode, wherein the switch circuit is configured to couple another individual one of the two or more of the plurality of inputs to the other one of the plurality of outputs in the second mode.
16. The system of claim 15 , wherein the switch circuit is configured to switch between the first mode and the second mode when a presence of a conductive object is detected in an area corresponding to one of the first or second groups in the first mode.
17. The system of claim 15 , wherein the processing device is configured to control the switch circuit to couple the first capacitance sensor and second capacitance sensor to the plurality of capacitive sense elements in the first and second modes.
18. The system of claim 15 , wherein:
the processing device is configured to perform a first scan to detect a presence of a conductive object while the switch circuit is in the first mode;
the processing device is configured to perform a second scan when the presence of the conductive object is detected in the first scan; and
the processing device is configured to not perform the second scan when the presence of the conductive object is not detected in the first scan.
19. The system of claim 18 , wherein:
in the first scan, the processing device measures, using the first capacitance sensor, a first capacitance on the first group of the two or more capacitive sense elements coupled together;
in the first scan, the processing device measure, using the second capacitance sensor, a second capacitance on the second group of the two or more capacitive sense elements coupled together; and
in the second scan, the processing device measures, using at least one of the first capacitance sensor or the second capacitance sensor, a third capacitance on each individual one of the two or more capacitive sense elements of one of the first or second groups,
wherein the one group corresponds to a first area in which the presence of the conductive object is detected during the first scan, and
wherein the two or more of the plurality of capacitive sense elements in the one group are not coupled together in the second mode.
20. The system of claim 15 , wherein the plurality of capacitive sense elements are arranged in a plurality of rows and in a plurality of columns, wherein the first group comprises two or more rows of the plurality of rows and the second group comprises two or more additional rows of the plurality of rows.