In this project we will connect Robot Car to Arduino Wifi Shield and Use a  Mobile APP to control    4-DOF robot arm movement.

Parts and Devices:

OSOYOO basic board fully compatible with Arduino UNO board https://osoyoo.store/products/osoyoo-uno-r3-for-arduino?variant=31955265290351
OSOYOO Wifi shield https://osoyoo.store/products/esp8266-wifi-shiled-osoyoo-wifi-internet-of-things-learning-kit-for-arduino-uno?variant=31955252215919
PCA9685 PWM control board https://osoyoo.store/products/pca9685-compatible-module?variant=32079312879727
补MG995舵机图片 MG995 Servo x 4
补机械手臂图片 4-DOF arm

Hardware Installation :

 Step 1: Insert to Osoyoo Wifi Shield onto your UNO board
Step 2: Install servos on Robot Arms and fix the base servo in some  servo platform.
Step 3: Connect 4 servo motor, PCA9685 and OSOYOO Wifi Shield as following graph:

PCA9685 Arduino UNO board
V+ Vin
PCA9685 Servo
PWM 15 Finger servo
PWM 14 Wrist servo
PWM 11 Arm servo
PWM 10 Base servo


Step 4: Make sure  Wifi Shield jumper caps in E_TX to D4 and E_RX  to D5   are connected.

Software Installation:

Open-source Arduino
Download Arduino IDE here:
7 zip is a free zip
utility that un-zips zip files
Download 7zip here for free
Osoyoo Wifi Robot APP search “Osoyoo Wifi Robot APP” in
Google Play or Apple Store

Step 1)   Download OSOYOO Wifi UDP Robot Car control APP
In Google Play or Apple Store, please search key words “OSOYOO Wifi UDP Robot Car”, you will find an orange icon APP as following:

You can also DOWNLOAD Android APP directly from  https://osoyoo.com/driver/arduino-udp/udp-robot.apk

Step 2) Install WifiESP and Adafruit-PWM-Servo-Driver-Library-master Library
Please download these two library zip files from

Open Arduino IDE ->click Sketch ->Include Library ->Add .ZIP library , then load above zip files into Arduino.

Step 3) Arduino Sketch code Installation:

Download: https://osoyoo.com/driver/wifi-robot-arm/wifi-robot-arm.zip

Unzip above file , you will see a wifi-robot-arm sub-folder.

1) Go to wifi-arm sub folder, Run     sketch code file wifi-robot-arm.ino

2) You need change following code in line 39,40:

char ssid[] = “***”; // replace this with your router wifi SSID

char pass[] = “***”; // replace with your wifi  password

3) Upload the sketch to Arduino. Finally, click the Serial monitor window in upper right corner of Arduino IDE, you will see following result:

4) In this mode, your will see an IP address which is our LAN IP address assigned by my router. Please write down this IP address and click Setting to set up robot IP address and set this IP address to your APP Setting section (no need change default port 8888 in APP).

Now your Robot car is connected to your LAN, you can use Mobile phone under same LAN to control the robot car. If your APP is in WAN, you need to go to your Router Control Panel, forward Port 8888 to Robot car LAN IP address, then you can use Router IP to control the car. This feature makes our robot car A REAL INTERNET OF THING device


Now your Robot car become a Wifi Hot Spot, you can use Mobile phone control the robot car.

Final Testing:

Trun on the car. Now click Setting to set up robot IP address, use default port 8888

To control the Robot Arm movement:

Key Movement
F1 open finger
F4 close finger
F2 arm down
F5 arm up
F3 rotate finger clockwise
F6 rotate finger counter clockwise
Rotate base clockwise
Rotate base countclockwise

Note: F1~F6 are further development functions in the future.

FAQ about the Wifi UDP APP and sketch Code:
Q 1)What happened when you press  buttons in OSOYOO WiFi UDP Robot Car APP ?
A: When you press a button of the APP, APP will send a single-letter message through UDP protocol to target device (in this example, our Arduino   Wifi Shield)

Button UDP message
F1 F
F2 G
F3 H
F4 I
F5 J
F6 K
obstacle O
tracking T