SunFounder GalaxyRVR review – An Arduino programmable Mars Rover-like robot for education

SunFounder sent us a GalaxyRVR 6-wheel robot for review. It looks like NASA’s Mars Rover robots but targets the education market with an Arduino UNO R3 compatible board and an ESP32-CAM board for WiFi connectivity and video capture.

The GalaxyRVR robot kit can transmit video signals over WiFi to explore planet Earth with your mobile device or tablet and the camera can be adjusted up and down thanks to a servo motor. The robot gets its power from a solar panel coupled with a battery and features sensors such as obstacle avoidance and ultrasonic modules.

SunFounder GalaxyRVR review

NASA’s Mars Rover exploration robots

NASA is currently using the Perseverance rover, also known as Percy, as the latest planetary exploration robot to land on Mars. It is designed to explore the Jezero Crater as part of NASA’s Mars 2020 mission. In addition to its scientific instruments, Perseverance also carries Ingenuity, a small experimental Martian helicopter.

SunFounder GalaxyRVR robot kit simulates a moving structure with the same Rocker-Bogie Mechanism system used in NASA’s Mars rover with the ability to explore all types of terrains. Whether it’s a rocky mountain, a sandy beach, or a grassy field, a vibration-dampening system helps the robot move smoothly.

NASA Mars Perseverance

What’s a Rocker-Bogie system?

The Rocker-Bogie system is a mechanism that can overcome environmental obstacles and has been designed to accommodate the unpredictable topography of Mars including steep slopes and large boulders. The system can cross obstacles and make use of its six wheels to navigate difficult terrain and explore different areas of the planet.

Rocker Bogie system

 

SunFounder GalaxyRVR kit unboxing and assembly

The SunFounder GalaxyRVR robot kit comes with over 300 pieces (including screws) which users must learn to assemble themselves. The instructions can be found on GitHub (PDF).

SunFounder GalaxyRVR Kit Parts

People who prefer video tutorials can check out the assembly instructions in the video below.

We’ll now go into detail about the key components of the kit. This is quite long, so you can jump to the programming part if you want to carry on with the review without knowing the details of each component.

SunFounde R3: GalaxyRVR control board

The SunFounder R3 is an ATmega328P-based microcontroller board with 14 digital I/O ports (6 of which can be used as PWM outputs), and 6 analog input pins. It connects to a computer via a USB device cable to upload a program and can be powered with an AC-to-DC adapter or a 7 -12V battery to get started.

SunFounder GalaxyRVR Arduino R3 Board

It’s basically a clone of the popular Arduino UNO R3.

SunFounder GalaxyRVR shield

The GalaxyRVR shield is an expansion board that fits on top of the SunFounder S3 Arduino board and features connectors for motors, RGB lights, IR obstacle avoidance sensors, the ESP32-CAM board, and ultrasonic modules.

SunFounder GalaxyRVR Shield

The expansion board also has a charging circuit and a PH2.0-3P connector for a LiPo battery. A full charge for an 18,650 7.4V 2,000mAh battery takes approximately 130 minutes.

SunFounder GalaxyRVR Shield Layout

List of ports on the GalaxyRVR shield:

  • Motor Port
    • Motor ports (right) – 3x motors can be connected with all 3 motors controlled by the same set of signal pins 2 and 3.
    • Motor ports (Left) – 3x motors can be connected with all 3 motors controlled by the same set of signal pins 4 and 5.
    • Port Type: XH2.54, 2P.
  • Camera I/F – 5-pin connector for camera adapter board port
  • Camera Servo – The servo on the camera is connected to. The brown wire connects to “-”, the red wire connects to “+”, and the yellow wire connects to pin 6.
  • Sensors
    • LEFT/RIGHT IR – 3-pin connectors for IR obstacle avoidance modules. The left obstacle avoidance module is connected to pin 8, the right obstacle avoidance module is connected to pin 7.
    • SONAR – 4-pin connector for both Trig & Echo pins
  • Misc
    • Reset Button – Press this button to reset the program on the Arduino board.
    • Indicators
      • Charge Indicator – Glows red when the shield is charging through the USB-C port.
      • Power Indicator –  Glows green when the power switch is in the “ON” position.
      • Battery Indicator – Two orange indicators represent different battery levels. They flash during charging and turn off when the battery needs charging.
    • Power Switch – Slide to ON to power on the GalaxyRVR
    • RGB Strip – For connecting 2x RGB LED strips
    • Mode Switch – The ESP32-CAM and the Arduino board share the same RX (receive) and TX (transmit) pins. So, when you’re uploading code, you’ll need to toggle this switch to the right side to disconnect the ESP32-CAM to avoid any conflicts or potential issues.
  • Power
    • Charge Port – 5V/2A USB-C port used to charge the battery
    • Battery Port – 6.6V~8.4V PH2.0 3-pin power input for a battery powering both the GalaxyRVR Shield and Arduino board
    • SOLAR – 2-pin connector for the solar panel

ESP32-CAM

The ESP32-CAM is a small OV2560 camera module with an ESP32-S WiFi module and a microSD card slot for storing images taken with the camera. It measures 27 x 40.5 x 4.5 mm and consumes only 6 mA.

ESP32-CAM

ESP32-CAM adapter board

The ESP32-CAM adapter board is an expansion board for the ESP32-CAM  used to connect it to the SunFounder GalaxyRVR robot.

SunFounder GalaxyRVR Adapter ESP32-Cam

The ESP32-CAM adapter board connects to the  SunFounder GalaxyRVR expansion board through a 5-pin ZH 1.5 connector.

SunFounder GalaxyRVR Shield Camera Port

HC-SR04 ultrasonic module

The GalaxyRVR robot also features an off-the-shelf HC-SR04 ultrasonic distance sensor with a range from 2 cm to 400 cm and an accuracy range of up to 3 mm.

HC-SR04 ultrasonic sensor SunFounder

The ultrasonic module port is connected tot the 5-pin connector on the SunFounder GalaxyRVR shield.

SunFounder GalaxyRVR Shield Sonar Port

 

IR obstacle avoidance module

The IR obstacle avoidance module is an infrared obstacle avoidance module that can detect objects ahead. It is generally used in robots. The detection range is from 2 cm to 40 cm, and objects of different colors have different levels of reflectivity. Therefore, the darker the object, the shorter the detection distance.

SunFounder GalaxyRVR IR Obstacle Avoidance Module

The IR obstacle avoidance module consists of one IR transmitter and one IR receiver. It emits an infrared light signal and when the emitted infrared light hits an object, it is reflected to the photoreceptor. When the light on the sensor board is detected, the status will be displayed, and it will send a low-level signal to the OUTPUT pin.

IR Receiver

The two IR obstacle avoidance modules are connected to the SunFounder GalaxyRVR expansion board through the 3-pin IR LEFT and IR RIGHT connectors.

SunFounder GalaxyRVR Shield IR Port

RGB LED strip

Two RGB LED strips with four R5050 RGB LEDs are part of the kit.

RGB LED Strip

They are connected to two 4-pin connected on the SunFounder GalaxyRVR shield.

SunFounder GalaxyRVR Shield RGB Strip Port

TT Gear Motor

Each wheel is attached to a TT gear motor. All gears are housed in durable plastic construction with a gear ratio of 1:120 and two 250mm wires with XH2.54-2P connectors (3V DC).

TT motor specifications:

  • Operating voltage – 3V ~ 4.5V DC
  • Number of shafts – Single shaft Gear ratio: 1:120
  • No-load current – 130mA
  • Rotational speed under load – 38rpm ±8%rpm
  • Starting voltage – 2V (maximum) when no load
  • Output torque – 3V ≥ 1.2 kgf.cm
  • Service life – 70-120H
  • Direction of rotation – two directions
  • Dimensions – 70 x 22.5 x 36.6 mm
  • Wire – gray and black 24 AWG, length 250 mm.
  • Connector – White XH2.54-2P
  • Weight – 28.5 grams

SunFounder GalaxyRVR TT Motor

Each TT gear motor is connected through a 2-pin connector on the SunFounder Galaxy RVR shield with three blocks of connectors for left and right motors.

SunFounder GalaxyRVR Shield Motor Port

Wheels

The SunFounder GalaxyRVR robot comes with 6 wheels each with a diameter of 75 mm and a width of 37 mm made of synthetic rubber material suitable to glide on all types of floors.

Robot wheel

Servo Motor

The servo motor is used to control the angular position of the camera with high precision. The servo motor features a metal gear, takes 4.8 to 7.4 volts DC input, and can rotate by up to 180 degrees.

SunFounder GalaxyRVR Servo 720x540.jpg

It is connected through a 3-pin connector to the GalaxuRVR shield.

Solar panel

A solar panel is a device that converts solar energy into electrical energy. It consists of a photovoltaic (PV) cell, which is made of semiconductor materials such as silicon. When sunlight hits the PV cell, it knocks electrons away from the atoms, and these electrons flow through the cell generating an electrical current. Solar panels can be used to produce electricity for a variety of purposes. This includes powering homes, businesses, and even entire communities. It is a clean, renewable energy source that can help reduce our dependence on fossil fuels.

Solar panel features

  • Output power – 6V/660mA
  • Time to fully charge the battery – 7.2 hrs (theoretical, assuming bright sunlight)
  • Dimensiosn – 170 x 170mm
  • Wire – gray and black 24AWG 200mm
  • Connector – White XH2.54-2P

Solar Panel

Battery

The battery pack is produced by SunFounder themselves. It consists of two 18,650 batteries with a capacity of 2000mAh. The connector is a 3-pin XH2.54 connector designed to be plugged into the GalaxyRVR shield.

Key features

  • Battery charging – 5V/2A
  • Battery output – 5V/5A
  • Battery capacity – 2x 3.7V 2,000mAh
  • Battery life – 90 minutes
  • Battery charging time – 130 minutes
  • Connector – 3-pin XH2.54

Mars Rover Robot Battery

SunFounder GalaxyRVR robot energy management

The main components of this power system are batteries and the solar panel taking power from the sun. Working in tandem, the GalaxyRVR robot can work at all hours of the day and night.

SunFounder GalaxyRVR Solar Panel Energy System

Getting started with SunFounder GalaxyRVR robot

The GalaxyRVR robot can be programmed in the C language with the Arduino IDE. The SunFounder GalaxyRVR robot required three libraries. Users need to go to the Library Manager to install them starting with the Servo library.

Add Servo Library in Arduino IDE

Repeat the same for the “SoftPWM” and “SunFounder AI Camera” libraries. Uploading programs to the SunFounder S3 board requires moving the upload switch to the right to disconnect from the ESP32-CAM.

SunFounder GalaxyRVR Upload Mode

Now slide the power switch to “ON” to turn on the GalaxyRVR robot.

SunFounder GalaxyRVR shield power on

Testing the RGB LED lights

To test the RGB LEDs, we performed a series of cycles to change the colors.

SunFounder GalaxyRVR Program Test LED Strip

Here’s the code for the test program:

Servo motor control test program to raise and lower the ESP32 camera.

We tested the servo motor by writing code adjusting the camera from 0 degrees to 180 degrees delaying the degree shift every 100 milliseconds.

SunFounder GalaxyRVR Test Servo

Sample code:

SunFounder Galaxy RVR robot’s movement testing

We then wrote a sample program to move forward, turn left, turn right, back, and stop the robot, with sequenced commands.

SunFounder GalaxyRVR Test Movement

Sample code:

Ultrasonic sensor testing

We wrote a sketch to read the value of the ultrasonic sensor and if the condition that the sensor reads more than 50 centimeters, the robot moves forward, while if the sensor reads less than 15 centimeters and more than 1 centimeter, the robot reverses for 500 milliseconds and turns left for 1.5 seconds.

SunFounder GalaxyRVR Test Ultrasonic Sensor

Arduino sketch:

Obstacles avoidance with the IR obstacle avoidance modules

We then wrote another program to read the value from the right and left obstacle avoidance modules. If the right IR sensor detects an object and the left IR sensor does not detect an object, the robot turns backward to the right at a speed of 150 and if the right IR sensor cannot detect anything, but the left IR sensor finds the object, the robot turn backward left at a speed of 150. If both sensors detect an object, the robot reverses at a speed of 150. In all other conditions, the robot moves forward.

IR Obstacle Avoidance Module

Sample code:

Sending images from the camera to a Web Browser

Our next test program aims to stream images from the ESP32-CAM board in a Web Browser. We must first connect to a WiFi network and open the Web Browser using the IP address of the robot (e.g. 192.168.1.xxx).

ESP32-CAM web video streaming

Arduino sketch:

Controlling the SunFounder GalaxyRVR robot through a mobile app

SunFonuder provides an Arduino sketch to let users control the GalaxyRVR robot from an app.
SunFounder GalaxyRVR Driving with App

Arduino sketch:


Once the program is running in the robot, you can go to your phone to find the GalaxyRVR SSID defined in the program.

SunFounder GalaxyRVR Choose Device WiFi Connect

Connect to it with the password in the program, in our case: 12345678.

SunFounder GalaxyRVR SmartPhone WiFi Connected

Now find the “SunFounder Controller” in the Google Play store or Apple App Store, and install it. Now start the app and tap on the connect icon in the top right corner.

SunFounder Controller app

After a successful connection to the robot, the name “GalaxyRVR” will appear.

SunFounder GalaxyRVR APP Connected

Now press the + icon and select the user interface “GalaxyRVR” to create a new controller.

SunFounder GalaxyRVR Choose Device

Finally, tap on the Play icon in the top right corner to display the video streaming from the ESP32-CAM module.

SunFounder GalaxyRVR App Controller

You can now control all functions of the GalaxyRVR robot such as showing RGB lights, controlling movements, avoiding obstacles, and even commanding the robot by voice. The video review below shows how it all works.

SunFounder GalaxyRVR Video Streaming

Sunfounder GalaxyRVR robot video review

Conclusion

SunFounder GalaxyRVR robot is quite a novelty as most wheel-based robots simply emulate a car.  But with this robot, students can learn about the Rocker-Bogie system used in NASA’s planetary exploration rover robots. It also features many functions such as obstacle avoidance, RGB LED strips., and live camera streaming over WiFi. Students can also learn about Arduino programming besides robotics concepts. Further details may be found in the documentation.

We would like to thank SunFounder for sending us the GalaxyRVR Mars rover robot kit for review. The GalaxyRVR robot kit can be purchased for $129.99 on the company’s online store or Amazon US.

CNXSoft: This article is a translation of the original review on CNX Software Thailand by Karnjonsak Janjam, edited by Suthinee Kerdkaew

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2 Comments
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Jeroen
28 days ago

Looks fun, but they should just remove the arduino and just run it all from the esp32.

VIRGILIO CESAR GARCIA LEANDRO
26 days ago

It is very interesting, I liked so much! With that I can make my classes of robotics much better.

Khadas VIM4 SBC