ROB0102

    Cherokey 4WD Mobile Platform (SKU:ROB0102) Cherokey 4WD mobile platform Contents      1 Introduction 2 Specification 3 Mainboard Pin Outs 3.1 Microcontroller Compatibility 3.2 Power Supply 4 Installation Steps 5 Sample Code 5.1 Simple Test Program 5.2 First Test 5.3 Control Test Program 5.3.1 Changing the Motor Direction in Code Introduction The Cherokey 4WD is a versatile mobile robot that is compatible with popular microcontrollers such as the UNO, MEGA2560, Romeo, etc. The Cherokey PCB is embedded with a L298P motor driver chip which allows it to drive two 6-12v DC motors with a maximum of 2A current. The integrated 2 way DC motor driver and XBee & APC220 socket allows you to start your project immediately without the need for an additional motor driver or wireless shield. The expansion plate significantly increases the surface area of the Cherokey allowing you to easily connect a 9g micro servo or a standard sized servo in two different locations so that you can install a robotic arm or ultrasonic/IR sensors. The prototyping area makes it convenient to install sensors on the robot. Double sided solder pads in the middle of the top place can be populated with DIP or SMD components to extend the robot's functions. The high strength aluminium alloy chassis provides flexibilitiy in rapid movement particularly in outdoor enviornments, such as grass, gravel, sand or sloped surfaces. The Cherokey 4WD mobile platform is also suitable for robot competitions and research-related projects. Specification          2 channel DC motor driver Solder prototyping areas Servo sized holes Mounting holes compatible with Arduino UNO, MEGA, Romeo, etc. Incorporates a dual H-bridge for bi-directional motor control Easy to connect external modules such as XBee, DFRobot Bluetooth and APC220 wireless modules 7 white LEDS surrounding the board's edge for cool lighting effects Gearboxed motors for extra torque Motor Specification: Gear Ratio 1:120 No-load speed(3V):100RPM No-load speed(6V):200RPM No-load current(3V):60mA No-load current(6V):71mA Stall current(3V):260mA Stall current(6V):470mA Torque (3V): 1.2Kgcm Torque (6V): 1.92Kgcm Size: 55mm x 48.3mm x 23mm Weight: 45g Mainboard Pin Outs In the above diagram the 4 digital I/O pins in the lower-right corner can connect to any digital pin of an Arduino or similar microcontroller. In order for it to work you must make sure the correct pins are assigned in your code. Note: D5 and D6 are PWM pins More Details:    PROG SWITCH: PROG:Set the switch in this position when uploading code if you plug in an XBee or Bluetooth module on to the Cherokey PCB RUN: Set the switch in this position to run the code after it has been uploaded MOTOR SELECT1: Short the pins with a jumpers to control Motor 2 and Motor 4 simultaneously MOTOR SELECT2: Short the pins with a jumper to control Motor 1 and Motor 3 simultaneously Note: If you want to control the motors independently, remove the jumpers from these pins Correct and incorrect method of shorting the pins Microcontroller Compatibility The Cherokey is compatible with most microcontrollers,such as Arduino UNO, Diecimila, Leonardo, Mega 1280,2560, ADK, Romeo etc. If you use the RoMeo, you have complete control of 4 motors simultaneously. Cherokey 4WD_DFRduino UNO Cherokey 4WD_Romeo Cherokey 4WD_Mega NOTE: 1 If you use Romeo or a Leonardo board where "RX0"&"TX0" are not exposed, you need to change "Serial" to "Serial1". 2 Turn the "PROG/RUN" switch to the "PROG" position when you are going to upl oad the sketch. 3 Turn the switch to "RUN" position when you are going to use Xbee,APC220 or other modules. Power Supply Install Battery on the back of the board.You can install 5xAA battery holder or lipo battery on the back of the board. Installation Steps Refer to the Instruction manual for detailed assembly steps Sample Code Simple Test Program Use Arduino IDE to upload the following sketch to the microcontroller via the USB port. In Arduino IDE's board settings, you can use "Arduino UNO". Under COM settings, select the microcontrollers COM port (the COM port will vary on your computer). (Make sure your COM port is correctly assigned to your microcontroller in the IDE or the program will not upload!) int speedPin_M1 = 5; //M1 Speed Control int speedPin_M2 = 6; //M2 Speed Control int directionPin_M1 = 4; //M1 Direction Control int directionPin_M2 = 7; //M1 Direction Control void setup(){ } void loop(){ carAdvance(100,100); delay(1000); carBack(100,100); delay(1000); carTurnLeft(250,250); delay(1000); carTurnRight(250,250); delay(1000); } void carStop(){ // Motor Stop digitalWrite(speedPin_M2,0); digitalWrite(directionPin_M1,LOW); digitalWrite(speedPin_M1,0); digitalWrite(directionPin_M2,LOW); } void carBack(int leftSpeed,int rightSpeed){ analogWrite (speedPin_M2,leftSpeed); //Move backward //PWM Speed Control digitalWrite(directionPin_M1,HIGH); analogWrite (speedPin_M1,rightSpeed); digitalWrite(directionPin_M2,HIGH); } void carAdvance(int leftSpeed,int rightSpeed){ analogWrite (speedPin_M2,leftSpeed); digitalWrite(directionPin_M1,LOW); analogWrite (speedPin_M1,rightSpeed); digitalWrite(directionPin_M2,LOW); //Move forward } void carTurnLeft(int leftSpeed,int rightSpeed){ //Turn Left analogWrite (speedPin_M2,leftSpeed); digitalWrite(directionPin_M1,LOW); analogWrite (speedPin_M1,rightSpeed); digitalWrite(directionPin_M2,HIGH); } void carTurnRight(int leftSpeed,int rightSpeed){ //Turn Right analogWrite (speedPin_M2,leftSpeed); digitalWrite(directionPin_M1,HIGH); analogWrite (speedPin_M1,rightSpeed); digitalWrite(directionPin_M2,LOW); } First Test After code has been uploaded to the microcontroller, unplug the USB cable from the board. Place the Cherokey on a flat surface and at ground level for safety. Turn the Cherokey on using the switch at the rear. It should go backwards, forwards, turn 90 degrees to the left and turn 90 degrees to the right. TROUBLESHOOTING TIPS: Batteries must be connected to make the motors move! If the Cherokey is only plugged in with USB power through the microcontroller, the motors will be under powered and will not work! If batteries are installed but the motors are not moving, make sure the switch at the rear of the Cherokey PCB is turned on The Cherokey's direction may vary depending on the wiring of the motors. If you think the directions are wrong, try switching the positive and negative wires If a problem persists, try editing the code to change the motor direction - covered in the Changing the Motor Direction in Code section below Control Test Program Now we can try another program that will give us keyboard control over the Cherokey. The advantage of this program is that we will be given feedback to predefined directions. By observing the robot's motion, you can debug the motor directions so that each motor is spinning the correct way. Upload the following code as before: /* # Edited by: Matt # Date: 2015.09.06 # Version: 1.1 # Product: Cherokey 4WD Mobile Platform # SKU: ROB0102/ROB0117 # Description: # Drive 2 motors with this Cherokey 4WD Mobile Platform # Connect D4,D5,D6,D7,GND to UNO digital 4,5,6,7,GND */ //Motor Definitions int E1 = 5; //M1 Speed Control int E2 = 6; //M2 Speed Control int M1 = 4; //M1 Direction Control int M2 = 7; //M2 Direction Control //DIRECTIONS //STOP void stop(void) { digitalWrite(E1, 0); digitalWrite(M1, LOW); digitalWrite(E2, 0); digitalWrite(M2, LOW); } //ADVANCE void advance(char a, char b) { analogWrite (E1, a); digitalWrite(M1, HIGH); analogWrite (E2, b); digitalWrite(M2, HIGH); } //MOVE BACKWARDS void back_off (char a, char b) { analogWrite (E1, a); digitalWrite(M1, LOW); analogWrite (E2, b); digitalWrite(M2, LOW); } //TURN LEFT void turn_L (char a, char b) { analogWrite (E1, a); digitalWrite(M1, LOW); analogWrite (E2, b); digitalWrite(M2, HIGH); } //TURN RIGHT void turn_R (char a, char b) { analogWrite (E1, a); digitalWrite(M1, HIGH); analogWrite (E2, b); digitalWrite(M2, LOW); } void setup(void) { int i; for (i = 4; i