About Punch in Air  Experiments on MAX25405 Optical IR Sensor Evaluation Kit

1. Punch in Air

Punch-In-Air is kind of gestures moving much faster. This is useful in Intense Interactive Comuter Games.

Experimenting on MAX25405 Gesture Sensor Kit shall include,

• What is Gesture Sensor,
• How it works,
• Can it works,
• Can it work fast,
• How fast it can work,
• It is easy to use, low power comsuption or cheap to use.

Fortunately, I am selected as chellenger and just got the kit, So as to find out some quick answers right away and Put simple Roadtest just in this blog below.

2.  What is Gesture Sensor

2.1 Touched and Touch Free Solution

Unlike “touched” devices such as mouses, keyboards, and touchscreen displays,which need hard surface to touch and wire to connect the touch-responsive hardware to center processor.

To get ride of the hardware, reduce cost, keep satilization, touch-free gesture control is definitely in-demanding. Unfortunately, previous efforts bring little progress. The RealSense Dual Camera system by Intel which announced close in 2021, and other similar products by Microsoft or Logitech prove costly and unpractical. Some simple solutions that give one-direction only detection prove cheap and valid, until this MAX25405 Evaluation Kit.

2.2 Gesture Sensor

The MAX25405 Optical IR Sensor Evaluation Kit (EV kit) is a complete system for demonstrating the MAX25405 optical IR sensor in a typical gesture and proximity-sensing application. The MAX25405 enables recognition of the gestures, mainly with the following parts,

MAX32620FTHR Microcontroller Platform
Interface Shield Board
MAX25405 Sensor Board

Such simple yet Flexible Gesture Solution Features, Refer to https://www.maximintegrated.com/en/products/sensors/MAX25405.html
● Lower Solution Cost than Camera-Based Systems
● Integrated Optics with ±20deg Field of View (FOV)
● Optimum Resolution for Dynamic Hand Gestures
● Built-in LED Driver with Ultra-Low-Power Operation
● 120kLux Ambient Light Performance

Here is how the Solution works,

The MAX32620FTHR catch signals from sensors and process the data to decode the gesture.

3. How it works

The out-of-factory firmware of MAX25405 Optical IR Sensor Evaluation Kit enables recognition of the following gestures:

Hand Swipe Left, Right, Up, and Down
Finger/Hand Rotation Clockwise and Counter-Clockwise
Air Click
Proximity Detection and Linger-to-Click

The application circuit operates by illuminating the user’s hand with a precision-controlled IR light source and measuring the reflected signal with the MAX25405’s 6x10 (60 pixel) IR sensor array. The four-LED IR light source is PWM controlled with external FETs from the MAX25405’s onboard FET driver. The return signal is analyzed with an embedded microcontroller that interprets the gestures.

In short, in stead of normal camera with serveral Mega Pixal, this sensor process only 60 pixals under Optical IR array. Sure, it is much faster.

Here is the block diagram of MAX25405

The proximity, hand-detection, and gesture-recognition functions are achieved by detecting the light reflected from the controlled IR-LED light source while rejecting ambient light. An integrated 6x10-element optical sensor array performs
the light measurements. This discrete light source is created externally with one or more FETs driven directly from the MA25405. The light source’s PWM duty cycle is programmable from 1/16 to 16/16. The LEDs are pulsed on one or more
times in a programmable sequence. This pulse sequence is repeated for every sample.

Then, next question is, Can-It-Work?

4. Can it works

4.1 Wiring of Hardware

Connect the USB and Attached 3.3V Power Core ,

4.2 Software

Download MaximGestureSensorEVKit_SetupV1-2-5.exe and install it.

4.3 Heat Map

First conntect the sensor board with SPI

Click Run to start in Heap map Tab, the sensor is sensitive regardless of the ambient light,

Click Stop to freeze the view

The result is impressive. It is quick and sensitive with FPS up to 76.

4.4 Gesture Recognization

Gesture is in another tab page. Click run to start,

Gesture is recognized as the hand moved, no sign popup if there is no sign detected

If detected, but could not classified , shows "X"

Other gesture in the acceptable list can be shown , like move in some direction

Push up-down as click

Rotate clockwise or counter-clockwise

4.5 Proximity

Proximity Tab show the detected distance as of Z-axis , but only one point is shown as average value in preset zones, default 2x2

The hand is detected with position and distance

Maximum of 3x4 regions,

Clearly, The MAX25405 gesture sensor works fine.

5. Plans underway

The rest experiment is good to go. I would like to experiment in customized development environment such as Keil MDK 5.21, first install the Device Package

In most cases, customized gesture definination and rich application shall be applied. The performance shall be evaluation in next blog.