Pulse- or frame-based communication using active stylus

1. A stylus comprising:

one or more sensors;

one or more electrodes configured to communicate with a device by receiving signals from and transmitting signals to a touch sensor of the device; and

one or more computer-readable non-transitory storage media embodying logic that is operable when executed to:

receive sensor data from the one or more sensors;

receive a first signal generated by the device;

generate a second signal by modulating a carrier signal based on the sensor data; and

transmit to the device, in response to the first signal, the second signal, the sensor data being obtainable by demodulating the second signal.

2. The stylus of claim 1 , wherein the first signal is the carrier signal modulated to generate the second signal.

3. The stylus of claim 1 , wherein the second signal is generated using one of:

amplitude modulation;

frequency modulation; and

phase modulation.

4. The stylus of claim 1 , wherein:

the one or more sensors comprise a pressure sensor and a button; and

the sensor data comprises pressure data and button state data.

5. The stylus of claim 1 , wherein the sensor data is digital.

6. The stylus of claim 1 , wherein the second signal is transmitted in a single electric pulse.

7. One or more computer-readable non-transitory storage media embodying logic that is operable when executed to:

receive sensor data from one or more sensors in or on a stylus, the stylus comprising one or more electrodes configured to communicate with a device by receiving signal from and transmitting signals to a touch sensor of the device;

receive a first signal generated by the device;

generate a second signal by modulating a carrier signal based on the sensor data; and

transmit to the device, in response to the first signal, the second signal, the sensor data being obtainable by demodulating the second signal.

8. The media of claim 7 , wherein the first signal is the carrier signal modulated to generate the second signal.

9. The media of claim 7 , wherein the second signal is generated using one of:

amplitude modulation;

frequency modulation; and

phase modulation.

10. The media of claim 7 , wherein:

the one or more sensors comprise a pressure sensor and a button; and

the sensor data comprises pressure data and button state data.

11. The media of claim 7 , wherein the sensor data is digital.

12. The media of claim 7 , wherein the second signal is transmitted in a single electric pulse.

13. A system comprising:

a device comprising a touch sensor; and

a stylus comprising:

one or more sensors;

one or more electrodes configured to communicate with a device by receiving signals from and transmitting signals to a touch sensor of the device; and

one or more computer-readable non-transitory storage media embodying logic that is operable when executed to:

receive sensor data from the one or more sensors;

receive a first signal generated by the device;

generate a second signal by modulating a carrier signal based on the sensor data; and

transmit to the device, in response to the first signal, the second signal, the device being operable to obtain the sensor data by demodulating the second signal.

14. The system of claim 13 , wherein the first signal is the carrier signal modulated to generate the second signal.

15. The system of claim 13 , wherein the second signal is generated using one of:

amplitude modulation;

frequency modulation; and

phase modulation.

16. The system of claim 13 , wherein:

the one or more sensors comprise a pressure sensor and a button; and

the sensor data comprises pressure data and button state data.

17. The system of claim 13 , wherein the sensor data is digital.

18. The system of claim 13 , wherein the second signal is transmitted in a single electric pulse.