For our open-source 360 camera trap project, we wanted to evaluate the field and figure out what the most available and useful cameras to hack would be. We collected about 6 commercially available camera traps and evaluated them on their

• Hackability
• Image Quality

In our qualitative order, here is a ranking of those cameras we have tested and the order we want to hack them:

Camera type	Object Pixel Density (front)	Object Pixel Density (side)	Distortion	Sensitivity to infrared	Price paid
MadV	127*127	133*133	None	Lowest	300
Ricoh Theta V	100*100	100*100	None	Highest	430
Samsung Gear	95*95	143*133	Some	Low	$83
Ricoh Theta S	100*100	100*100	None	High	270
Zision	166*166	90*110	Most	Low	$60
Maginon View	50*50	45*50	Some	Low	$55

Basic Testing Procedure

Object Pixel Density

We took all of the cameras in a room with controlled lighting, and placed a colorful, standard-sized basketball exactly 2 meters away from each camera.

Two pictures were taken in two camera positions, one with a lens straight in front of the subject, one with the camera sideways (or upwards for the Zision). The object is positioned at 2 meter.

IR Sensitivity

To test the cameras’ sensitivity to infrared light. We placed the same calibration object (the colorful basketball) at a distance of 2 meters, with the camera positioned between the subject and the light.

Xiaomi MADV (Mijia Sphere)

General Camera Details

Price
$349 ($299 on sale)

Object Pixel Density + IR Sensitivity

The MadV has a resolution of 127*127 px when ball is in front of the camera and 133*133 px from side view. Its sensibility to infrared light is quite poor. With the target at a distance of 2 meter, it was not able to show anything.

Picture with infrared light

Front                          

Side

Ricoh Theta V

Video Stitching Resolution	4K
Internal/External Stitching	Internal Stitching
360 Stitched Video Format	Internal:3840 x 1920 at 29.97 fps (56 Mb/s MP4 via H.264) 1920 x 960 at 29.97 fps (16 Mb/s MP4 via H.264)
Still Image Resolution	JPEG: 14 Megapixel, 5376 x 2688 (2:1)
Number of Lenses	2

Camera per Lens

Sensor

1-Chip 1/2.3″ CMOS

Optics per Lens

Maximum Aperture	f/2
Lens Elements	7
Minimum Focusing Distance	4.0″ / 10.2 cm

Recording

Recording Media	x Internal Flash Memory
Built-In Mic	Yes
Channels	4.0-Channel Surround
Audio Format	AAC-LC

Exposure Control

Shutter Speed	1/25000 – 1/8 Second (Photo)1/25000 – 60 Seconds (Photo)1/25000 – 1/30 Second (Video)1/25000 – 1/30 Second (Streaming)
Photo ISO Range	100 – 1600 (Auto)64 – 3200 (Manual)
Video ISO Range	64 – 6400 (Auto)

The Ricoh Theta V showed a resolution of 100*100 px, no matter which position the camera was in.

Picture with infrared light.

Front                         

  Side

Its sensibility to infrared light is the highest of all the cameras tested.

Price
$429 ($379 on sale)

Samsung Gear 360 4K Spherical VR Camera

Image Sensor	2 x 8.4 MP CMOS
Lenses	2 x f/2.2 ultra-wide lenses
Max Video Resolution	360° Dual Lens: 4096 x 2048 at 24 fpsSingle Lens: 1920 x 1080 at 60 fps
Video Format	MP4 (H.265)
Photo Capture Resolution	360° Dual Lens: Up to 15 MP (5472 x 2736)Single Lens: Up to 3 MP (2304 x 1296)
Photo Format	JPEG
ISO	Up to 1600
Mic	Built-in stereo microphone
Recording Time	Up to 130 minutes in 2560 x 1280 resolution at 30 fps
Battery	1160 mAh
Card Slot	1 x microSDXC card slot (supports up to 256 GB cards)
Supported Operating Systems	Android, iOS, Mac, Windows (360 Video Editor is not available for macOS computers)
Wi-Fi	802.11 a/b/g/n/ac (2.4/5 GHz)
Bluetooth	4.1
Interface	1 x USB 2.0 Type-C
Sensors	Gyro, accelerometer

Picture with infrared light

Front                       

  Side

The Samsung Gear has a resolution of 95*95 px when positioned straight front of the ball, and 143*133 sideways. This camera shows a high level of distortion at the latter position, and has a slightly lower resolution compared to both Thetas.

It proved somewhat sensible to infrared light, though noticeably less than that of both Thetas.

Price
$82.99 (though as of September 2019 price went up to $200)

Ricoh Theta S

Picture with infrared light

Front                       

    Side

The Ricoh Theta S has, just as the Theta V, a resolution of 100*100 px for both sides. Its sensibility to infrared light was a bit less than that of the Theta V, but higher than that of the Samsung Gear.

Price
$269,32

Zision 360°Panoramic VR Full View Action Camera

Picture with infrared light

Side                            

Up

The Zision has a resolution of 166*166 px when positioned with its only lens facing the subject directly, but the picture shows highly distorted when positioned with the lens upwards.

Its sensibility to infrared light was poor, only a bit higher than that of the MadV.

Price
$59.99

Maginon View 360

50 euros (discount price)

http://www.maginon.com/website/uk/actioncams/view360/

Type of camera     Full-spectrum camera for 360° spherical panoramas

Image sensor     2x 2MP CMOS sensor

Photo resolution     8 MP (4,000 x 2,000 | interpolated), 5 MB (3,200 x 1,600 | interpolated), 3 MP (2,592 x 1,296)

Video resolution     2.048 x 1.024 (30fps)

Lens     2x 210° super wide-angle lens

Aperture     F = 2.0 | Focal length f: 0.88 mm

Recording time     Up to 120 minutes with fully charged battery (without WiFi, 2048 x 1024 / 30fps)

Memory     MicroSD card up to 32 GB (min. class 10 or faster)

Connections     Micro USB connection

Power supply     1,300 mAh lithium-ion battery

Dimensions     137 x 45 x 14 mmWeight     83 g

Picture with infrared light

Front         

Side

The Maginon has a resolution of 50*50,  and showed a bit of distortion when the camera is positioned sideways. Its sensibility to infrared light was similar to that of the Zision.

Price
$110,00 ($55.00 in sale)

This guide will show you the steps necessary to turn a commercially available Xiaomi MADV (mijia) into a fully functioning, animal sensitive, weatherproof Camera trap!

Code

Code is available in this repo https://github.com/Digital-Naturalism-Laboratories/Panatrap/tree/master/MADV

Hardware

Physical Designs are available here for free download: https://a360.co/2nrPLd8

and included in the Github https://github.com/Digital-Naturalism-Laboratories/Panatrap/tree/master/MADV

Hacking Theory

The MADV designers made an interface on the bottom of the camera for the camera to be easily controlled with their included “selfie stick.” It’s just two metal electrode contacts that when connected it sends a message to the camera(the original selfie stick has a 220 ohm resistor connected to a button).

From our examinations, the 3 messages you can send to the camera with this interface are:

• Long Press (5 seconds)
• Camera ON/OFF
• Medium Press (2 seconds)
• Toggle Recording Mode (Video to Photo, or Photo to Video)
• Short press (0.5-1 seconds)
• Shutter Button (Take a photo, or start or stop a video)

Cut out or Print the Design

You will need to cut out two main parts of the design:

The Housing – These are the parts that will go around the camera and Arduino, and hold all the pieces together to make the project function

The Weather Shield – This is a 360-degree transparent case that lets the camera stand up again

In the link and the repo, these are 2-dimensional drawing files mean to be laser cut from 3mm acrylic. The full 3D model is there, though, so you could 3D print the housing instead if you don’t have a laser cutter.

I kept the the weather shield quite simple in design as well, so if you do not have a laser cutter, you can pretty much just make a box from clear acrylic that goes aroundDIY

DIY Pogo Pins / Prepare the Contact Connector

Ideally you would have these things called “Pogo pins” which are little spring mounted pins that press against electrical contacts such as those on the bottom of your MADV. If you have those, great! solder wires to two of them with one header pin space in between.

If you are out in the jungle, and don’t have Pogo pins, though, we can make our own ones. You just need:

• Standard Male Header pins (3 linked together)
• Chunk of hard rubber (we used a piece of our silicone soldering mat)
• 2 wires

Take your set up 3 header pins, chop off the middle pin, and stab them all into the hunk of rubber cut to the size of the area in the camera housing for the electrodes. Solder two wires to the outside pins. They should line up directly with the electrical contacts of the camera. The rubber gives the mechanism some squishiness, so you can ensure a good contact with the camera.

Connect all the Electronics

Now you just need to connect the components together!

The camera has two electrical contacts you just put together. The wire running to the contact closest to the center of the camera should go to the GND pin on your arduino.

The outside wire contact should go to pin 12 on your arduino.

Now you just need to connect the PIR motion sensors.

PIR

If you are using a 5V power source,

simply connect the Vin lines on the PIRs to the 5V on the arduino

The GND to the GND on the Arduino

and the OUT pins on the PIR to pins A4 and A3 on your arduino

Program

The code is all up at: https://github.com/Digital-Naturalism-Laboratories/Panatrap/blob/master/MADV/Code

This first, simple sketch should let you debug easily and make sure your PIR’s are working and your camera is triggering and shutting down correctly

/*
  PanaTrap - MADV
  Debug Code for the turning the Xiaomi MiSphere (MADV) camera
  into a remotely controlled,
  PIR triggered, Camera Trap
*/

/* in order to trigger the MADV camera to change modes, in theory you should connect a relay to your arduino, and trigger that to connect the nodes of the MADV
  //But we are trying to use minimal hardware, and found that if you connect the node closest to the center of the camera to the ground, and then
  //Connect another digital pin  to the other node
  //Initially set the digital pin to HIGH, and then when you pull it LOW
  //it will trigger the camera
  - Long Press (5 seconds)
  - Camera ON/OFF
  - Medium Press (2 seconds)
  - Toggle Recording Mode (Video to Photo, or Photo to Video)
  - Short press (0.5-1 seconds)
  - Shutter Button (Take a photo, or start or stop a video)
*/

//Front PIR motion sensors
int fPIR = A4;
int fPIRval = -1;

//Back PIR motion sensors
int bPIR = A3;
int bPIRval = -1;

//camera trigger operants

int trigger = 12;
int gndtrigger = 9;


//LED for debugging display
int led = 13;


void setup() {
  //Serial for debugging PIRs
  // initialize serial communication at 9600 bits per second:
  Serial.begin(9600);

  //Turning some of the pins on the camera into virtual Power sources and Grounds
  pinMode(A1, OUTPUT);
  digitalWrite(A1, LOW);

  pinMode(A2, OUTPUT);
  digitalWrite(A2, HIGH);

  pinMode(A5, OUTPUT);
  digitalWrite(A5, LOW);


  //Camera Trigger stuff
  pinMode(led, OUTPUT);
  pinMode(trigger, OUTPUT);
  pinMode(gndtrigger, OUTPUT);

  digitalWrite(led, HIGH);

  digitalWrite(trigger, HIGH);
  digitalWrite(gndtrigger, LOW); //**Andy note A

}

// the loop routine runs over and over again forever:
void loop() {
  // read the input on analog pin 0:
  fPIRval = analogRead(fPIR);
  bPIRval = analogRead(bPIR);
  // print out the value you read:
  Serial.print(fPIRval);
  Serial.print("    rear:  ");
  Serial.println(bPIRval);


  if (fPIRval > 600 || bPIRval > 600) {
    critterDetected();
  }
  delay(1);        // delay in between reads for stability
}

void critterDetected() {

  Serial.println("Critter detected");
  //Turn camera on
  onOffCamera();

  //Take a photo
  takePhoto();
  takePhoto();

  //TODO: Wait to see if other critters still around
  //before we shut off camera

  //TODO: the camera will toggle between photo and video each time it shuts off, add in a toggle here

  onOffCamera();

}

void onOffCamera() {
  Serial.println("cameraONOFF");

  //5 second turn on
  digitalWrite(led, LOW);
  digitalWrite(trigger, LOW);
  digitalWrite(gndtrigger, LOW);
  delay(5000);

  ///Chill
  digitalWrite(led, HIGH);
  digitalWrite(trigger, HIGH);
  digitalWrite(gndtrigger, LOW);
  delay(2000);
}

void takePhoto() {
  Serial.println("Take photo");

  //Take a photo
  digitalWrite(led, LOW);    // turn the LED off by making the voltage LOW
  digitalWrite(trigger, LOW);  // turn the LED on (HIGH is the voltage level)
  digitalWrite(gndtrigger, LOW);
  delay(1000);               // wait for a second

  ///Chill 4 secs
  digitalWrite(led, HIGH);
  digitalWrite(trigger, HIGH);
  digitalWrite(gndtrigger, LOW);
  delay(4000);

}

void togglePhotoVideo() {
  Serial.println("cameraTogglePhotoVideo");

  //2 second press
  digitalWrite(led, LOW);
  digitalWrite(trigger, LOW);
  digitalWrite(gndtrigger, LOW);
  delay(2000);

  ///Chill
  digitalWrite(led, HIGH);
  digitalWrite(trigger, HIGH);
  digitalWrite(gndtrigger, LOW);
  delay(2000);

}

Charge all your devices

In this build, the MADV has its own internal battery, and the Arduino is connected to its own re-chargeable LIPO

Assemble and Deploy

Now that it is ready, give the PIR’s a quick wave, and test that everything is triggering. Now set it in the target environment, and test it again by jumping in front of it and seeing if you can detect it. (You will have lots of 360 selfies with testing this camera).

If it all seems good, leave it there and come check on it in a couple hours or days and see what you caught!