Most of the time, i'm wondering where is the ISS looking up the sky. To answer this question, i've made a physical object to know exactly where is the ISS in real time.

The ISS Tracking Lamp is a Internet connected lamp which constantly tracks the ISS and displays it location on Earth’s surface (printed in 3D).

Bonus: the lamp also displays the sunny side of Earth with Neopixels!🌎🛰

So, in this Instructables, we are going to see the differents steps to build this lamp based on WEMOS D1 Mini, stepper motor, servo motor, laser and 3D parts.

I build all by myself, except for the 3D printed Earth, which was purchased on Aliexpress.

Software :

Arduino based code
API ISS Location : Open Notify - Current Location of the ISS (by Nathan Bergey)
Parsing data : ArduinoJson Library (by Benoit Blanchon)

CAD & Parts :

3D Printed Earth of 18cm diameter (purchased on Aliexpress : here )
3D printed motor supports - designed with Fusion 360 and printed with Prusa i3 MK2S
Copper tube
Concrete base, made with The French Vikings

Hardware :

Microcontroller : Wemos D1 Mini (wifi antenna integrated)
Servo EMAX ES3352 MG
Stepper Motor 28byj-48 (with the ULN2003 driver board)
10 NeoPixels LED
Laser of 405 nm wavelength
Limit Switch
5V 3A Power Supply

Step 1: Modeling Parts in Fusion 360 and Printing

To mount all the hardware, we are going to create the core assembly base on 3D parts. The parts are available on Thingiverse here.

There are 3 parts :

1) The Support Stepper Longitude

This part is made for mounting the stepper motor, the WEMOS, the Neopixels strip and the copper tube

2) The Support Switch

This part is made for mounting the limit switch (use to indicate to the stepper the latitude -0°/-180°). It's screwed on the top of the stepper

3) The Support Servo Latitude

This part is made for mounting the servo motor. The Support Servo is mounted on the stepper motor

All the parts were printed on Prusa I3 MK2S, with black PETG filament

Step 2: Wiring and Assembling

This circuit will have a 5V 3A power input (in order to use the same supply for the stepper driver, the laser, the Neopixels and the WEMOS)

By the following Sketch, we need to solder the power supply directly to the elements above in parallel:

Stepper Driver
Laser
Neopixels strip (NB : there are 10 Neopixels in reality, not 8 as the sketch shows)
WEMOS

Next, we need to connect the different elements to the WEMOS :

1) The stepper driver following this list:

IN1->D5
IN2->D6
IN3->D7
IN4->D8

2) The servo motor following :

Data Servo Pin -> D1

3) The Neopixels strip following :

Data Neopixels Pin -> D2

4) The limit switch following :

The two pins of the switch to the GND and D3

Connect the limit switch in a manner that the circuit is opened/broke when we push on the switch (so the circuit is closed when nothing push on it). This is to avoid any wrong lecture due to a voltage peak.

Step 3: Arduino Code - Getting the ISS Position in Real Time

To drive the two motors to reach the position of the ISS, we need to get the position of the ISS in real time :

For that first we will use the API from Open Notify Here
Then, we need to parse the data to get simple value of the ISS location with the help of Parsing data : ArduinoJson Library (by Benoit Blanchon)

#include <ESP8266WiFi.h
#include <ESP8266HTTPClient.h
#include <ArduinoJson.h

// WiFi Parameters
const char* ssid = "XXXXX"; 
const char* password = "XXXXX";
void setup() {
Serial.begin(115200);
WiFi.begin(ssid,password);
while (WiFi.status()!= WL_CONNECTED) {
    delay(1000);
    Serial.println("Connecting...");
    }
}

This program connects the NodeMCU to the WiFi, then connects to the API, get the data and print it to by serial.

void loop() {

if (WiFi.status() == WL_CONNECTED) // Check WiFi Status
	{HTTPClient http;  //Object of class HTTPClient
	http.begin("http://api.open-notify.org/iss-now.json");
	int httpCode = http.GET();   //Check the returning code

if (httpCode >0) { // Parsing
		const size_t bufferSize = JSON_OBJECT_SIZE(2) + JSON_OBJECT_SIZE(3) + 100;
		DynamicJsonBuffer jsonBuffer(bufferSize);
		JsonObject& root = jsonBuffer.parseObject(http.getString());		// Parameters
		const char* message = root["message"];
		const char* lon = root["iss_position"]["longitude"];
		const char* lat = root["iss_position"]["latitude"];		// Output to serial monitor

Serial.print("Message:");
		Serial.println(message);
		Serial.print("Longitude: ");
		Serial.println(lon);
		Serial.print("Latitude: ");
		Serial.println(lat);
	}
	http.end();   //Close connection
}
delay(50000);
}

Step 4: Final Arduino Code

The following Arduino code get the ISS location to move the laser to the right place on the Earth's surface, and the getting the position of the sun to light up the concerned Neopixels to light up the surface of the Earth touch by the sun.

Bonus 1 : When the lamp is switched on, during the phase of initialization, the laser will point the position of the lamp (id : the position where the router is)

Bonus 2 : When the ISS is next to the lamp location (+/- 2° long. and +/-2° lat.), all the Neopixels will gently wink