Electronic device for selective transmission of downlink signal to sensor controller
Allocation of slots to different styluses is flexibly changed in units of the slot that is shorter than a frame. A stylus bi-directionally transmits and receives signals to and from a sensor controller connected to a sensor via capacitive coupling. The stylus includes a memory that temporarily stores a value of a local ID. The stylus includes a controller that determines whether or not a detected uplink signal includes the value of the local ID stored in the memory every time the uplink signal transmitted by the sensor controller is detected. The controller, in response to determining the detected uplink signal includes the value of the local ID stored in the memory, generates a downlink signal that is based on an operation state and transmits the downlink signal to the sensor controller.
1. An electronic device comprising:
a plurality of electrodes including a first electrode and a second electrode;
a switching circuit configured to select one of the plurality of electrodes; and
a processor which,
in response to receiving a first uplink signal via the first electrode, transmits a first downlink signal via the first electrode to the sensor controller,
after transmitting the first downlink signal via the first electrode, controls the switching circuit to select the second electrode, and
in response to receiving a second uplink signal via the second electrode, transmits a second downlink signal via the second electrode.
2. The electronic device according to claim 1 , comprising:
an elongated body,
wherein the first electrode of the plurality of electrodes is disposed at one end in a longitudinal direction of the elongated body and the second electrode of the plurality of electrodes is disposed at another end in the longitudinal direction of the elongated body.
3. The electronic device according to claim 2 , wherein the electronic device is an electronic ruler.
4. The electronic device according to claim 2 , wherein the plurality of electrodes include three or more electrodes disposed along the longitudinal direction of the elongated body.
5. The electronic device according to claim 1 , wherein the processor controls the switching circuit to sequentially select the plurality of electrodes according to a schedule which allocates a plurality time periods to the plurality of electrodes.
6. The electronic device according to claim 5 , wherein the processor receives the schedule configured by the sensor controller.
7. The electronic device according to claim 6 , wherein the processor receives the schedule in at least one of the uplink signals transmitted from the sensor controller.
8. The electronic device according to claim 5 , wherein the schedule is dynamically set.
9. The electronic device according to claim 8 , comprising:
a detector,
wherein the processor, in response to the detector detecting movement of the electronic device below a threshold, dynamically sets the schedule to allocate less time for transmission of the downlink signals than time allocated for transmission of the downlink signals when detected movement of the electronic device is above the threshold.
10. The electronic device according to claim 1 , further comprising a reception electrode that is used exclusively to receive an uplink signal.
11. The electronic device according to claim 10 , wherein the reception electrode is used to receive the uplink signal according to a Bluetooth® standard.
12. An electronic device comprising:
two or more electrodes including a first electrode and a second electrode;
a first switch configured to switch a state of the electronic device between a working state and a stop state;
a switching circuit configured to select one of the two or more electrodes; and
a processor which,
in response to receiving a first uplink signal via the first electrode, transmits a first downlink signal via the first electrode to a sensor controller when the electronic device is in the working state,
after transmitting the first downlink signal via the first electrode, controls the switching circuit to select the second electrode,
in response to receiving a second uplink signal via the second electrode, transmits a second downlink signal via the second electrode, and
stops transmission of the second downlink signal via the second electrode when the electronic device is in the stop state.
13. The electronic device according to claim 12 , wherein the electronic device is an electronic ruler.
14. The electronic device according to claim 12 , comprising:
a second switch,
wherein the processor, in response to the second switch being operated when the electronic device is in the working state, includes in at least one of the downlink signals information indicating an operated state of the second switch.
15. The electronic device according to claim 14 , wherein the operated state of the second switch commands a defined processing to the sensor controller.
16. The electronic device according to claim 15 , wherein the defined processing is finalization of information inputted by the electronic device.
17. The electronic device according to claim 15 , wherein the operated state of the second switch commands an external electronic apparatus including the sensor controller to execute the defined processing.
18. The electronic device according to claim 17 , wherein the electronic device is an electronic ruler, and
wherein the operated state of the second switch commands the external electronic apparatus to display a virtual line based on information inputted by the electronic ruler.
19. The electronic device according to claim 18 , wherein at least one of the downlink signals includes an indication that the electronic device is an electronic ruler.