IR Seeker Working Theory

How does QikEasy IR Seeker work?

Our Secret Sauces

 

Unlike other commercial products or most DIY sensors, QikEasy IR Seeker uses real 40KHz (which is the frequency of the carrier wave output by the IR Ball) IR receivers and not the 38KHz ones.  Additionally, instead of reading the strengths through the analog method (after passing the IR receiver output through a Low Pass filter), our speedy microcontroller does all the heavy lifting in measuring the inverted pulse widths of the IR receiver outputs which are used to calculate the IR signal strength thus the distance from the IR Ball.

 

Here are the main ingredients of our secret sauce in achieving the great accuracy:

    • Use IR receivers with filter for 40KHz carrier, not 38KHz.
    • Calculate signal strengths digitally by measuring pulse widths of the IR Receiver outputs.
    • Use running averages of measured strength values to smooth out the values.
    • Our IR receivers are pre-matched through our proprietary calibration process.  This ensures that the 5 IR Receivers on each IR Seeker board return approximately the same values for IR signals of same intensity.
    • Specially designed enclosure is optically optimized to allow QikEasy IR Seeker to offer the most accurate directional results.

Emulated Color Sensor Measurements

 

With the Expander and IR Seeker(s) connected, IR Seeker measurements are delivered to the Spike Prime hub as Color Sensor attributes.

 

The data returned by each IR Seeker includes Angular Direction and Signal Strength.

 

Angular Direction

IrSeeker Returned Values Large

Angular Direction is the direction for the location of the IR Ball relative to the QikEasy IR Seeker.

 

    • Returns 0 for no signal detected.
    • Returns 1 – 9 depending on the detected location of the IR Ball as indicated by the diagram above.
    • Note that the values sent to the Spike Prime hub (Spike App 3) has most likely been multiplied by 4, unless you are using Spike App 2. See the Usage page for more details.

 

Signal Strength

 

Signal Strength provides a rough idea of the distance from the IR Seeker to the IR Ball. The closer the distance, the higher the signal strength.  Note that this value is very rough and can fluctuate quite a bit in real time.

 

    • Returns value between 0 and 1024 for Spike App 3.
    • Returns value between 0 and 255 for Spike App 2.