Safety sensors

1. A garage door sensor system comprising:

a transmitter source configured to transmit an electromagnetic (EM) waveform; and

a receiver circuit configured to receive the electromagnetic waveform from the transmitter source,

wherein the receiver circuit is configured to determine an active duration of the received electromagnetic waveform in a predetermined detection time window, and

wherein the receiver circuit is configured to send a blocked beam signal based on the determined active duration and the predetermined detection time window.

2. The garage door sensor system of claim 1 , wherein the receiver circuit is configured to send the blocked beam signal based on the relative durations of the active duration and the duration of the predetermined detection time window.

3. The garage door sensor system of claim 1 , wherein the receiver circuit is configured to send the blocked beam signal when a ratio of the active duration to a duration of predetermined detection time window is less than a predetermined density detection threshold.

4. The garage door sensor system of claim 1 , wherein the receiver circuit comprises a receiver sensor configured to receive the electromagnetic waveform and a microcontroller configured to determine the active duration based on the received electromagnetic waveform.

5. The garage door sensor system of claim 1 , wherein the active duration is a period during which the received electromagnetic waveform is at a signal high value.

6. The garage door sensor system of claim 1 , wherein the transmitter source and the receiver circuit are configured to share a wired connection to an interface of a garage door motor assembly, and wherein the wired connection is configured to provide both a power and communication connection for the transmitter source and receiver circuit.

7. The garage door sensor system of claim 1 , wherein the system comprises a plurality of transmitter sources and a plurality of receiver circuits.

8. The garage door sensor system of claim 7 , wherein each receiver circuit of the plurality of receiver circuits independently comprises at least one of a voltage converter, a micro-controller, an indicator LED, an EM photodetector, or a combination thereof.

9. The garage door sensor system of claim 1 , further comprising a transmit controller configured to control the transmitter source such that transmitter source transmits the electromagnetic waveform during predetermined time intervals of a recurring transmit cycle.

10. The garage door sensor system of claim 1 , wherein the receiver circuit is configured to synchronize the start of the predetermined detection window based on a synchronization pulse transmitted by the transmitter source.

11. The garage door sensor system of claim 1 , further comprising a plurality of transmitter sources and a transmit controller, wherein the transmit controller is configured to control at least one of the plurality of transmitter sources such that the plurality of transmitter sources transmit a plurality of waveforms non-simultaneously, wherein each of the plurality of waveforms is transmitted by a respective one of the plurality of transmitter sources.

12. The garage door sensor system of claim 1 , wherein the receiver circuit comprises a receiver sensor and a receive controller, wherein the receive controller is configured to send the blocked beam signal to an interface of a garage door motor assembly indicating that an object is intersecting a spatial surface between the transmitter background and the receiver background.

13. The garage door sensor system of claim 12 , wherein the receive controller is configured to determine a receive density of electromagnetic waveforms received by the receive sensor, and wherein the receive controller is configured to send the blocked beam signal to the interface of the garage door motor assembly based on the determined receive density.

14. A receiver circuit for a garage door sensor system, the receiver circuit comprising

a receive sensor configured to receive an electromagnetic waveform from a transmitter source; and

a receive controller configured to determine an active duration of the received electromagnetic waveform in a predetermined detection time window,

wherein the receive controller is configured to send a blocked beam signal based on the determined active duration and the predetermined detection time window.

15. The receiver circuit of claim 14 , wherein the receive controller is configured to send the blocked beam signal based on the relative durations of the active duration and a duration of the predetermined detection time window.

16. The receiver circuit of claim 14 , wherein the receive controller is configured to send the blocked beam signal when a ratio of the active duration to a duration of the predetermined detection time window is less than a predetermined density detection threshold.

17. The receiver circuit of claim 14 , wherein the active duration is a period during which the received electromagnetic waveform is at a signal high value.

18. The receiver circuit of claim 14 , wherein the transmitter source and the receiver circuit are configured to share a wired connection to an interface of a garage door motor assembly, and wherein the wired connection is configured to provide both a power and communication connection for the transmitter source and receiver circuit.

19. The receiver circuit of claim 14 , wherein the receive controller is configured to synchronize the start of the predetermined detection window based on a synchronization pulse received from the transmitter source.

20. The receiver circuit of claim 14 , wherein the predetermined detection window is longer in duration than a transmit pulse transmitted by the transmitter source.