Hexbug Spider Hacking Kit (no solder) by EMGRobotics.com

Transcription

1 Hexbug Spider Hacking Kit (no solder) by EMGRobotics.com This low-cost hack (less than $40 including the cost of the Hexbug spider) converts the remote control toy into a C programmable autonomous robot with an IR range sensor "eye" and a TI MSP430G bit brain. After this hack the robot will be able to turn left or right and walk forward or backwards and follow a line of black electrical tape under the control of the EMGRobotics MSP430G2553 Robot Controller Board (RCB). The Hexbug(tm) Spider is a remote control walking toy you can buy at your local RadioShack, Target, Wal-Mart, or ToysRus for about $ From the store, the spider is controlled by an IR remote and can walk forwards, backwards, and turn left or right. The walking gate of the spider is creepily realistic and fun to watch. You can purchase the Hexbug Spider at Target, radio Shack, or online This hack will replace the Hexbug electronics with the EMGRobotics MSP430G2553RCBLB (the board that comes in the hacking kit). After removing the Hexbug electronics board, four motors wires will need to be cut (as close to the board as possible) and the ends of the wires stripped. Those four wires will connect to the EMGRobotics MSP430G2553RCBLB using screw terminals. The new board is mounted to the spider using the double sided tape provided in the kit. So, let's begin the hack.

2 Tools required for this hack: Wire clippers, small Phillips #0 screwdriver, and small flathead 3/64 " screwdriver.

3 After removing the Hexbug from its packaging, flip the robot over and find the battery compartment screw shown below. After removing the battery cover, remove the batteries. Note the three screws under the battery cover in the images below. Remove these 3 batteries

4 After removing the three screws, slowly lift the top off the spider. Cut the red and black wires near the batteries. Put the top off the spider off to one side. Slowly remove the circuit board. Be careful of the 4 black and white wires. Cut red and black wires here.

5 Remove the plastic insert from the top of the spider (the part that contained the batteries). This can be done by grabbing the plastic insert with a pair of pliers and slowly twisting. The top of the Hexbug spider (the part that did contain the batteries). This plastic insert must be removed by twisting it out with a pair of long nose pliers. Plastic insert has been removed.

6 Cut the black and white wires (shown below) as close to the circuit board as possible. After the wires are cut, the original Hexbug board can be discarded. Cut these white and black wires as close to the circuit board as possible using wire cutters. After cutting the wires as close to the board as possible, the original Hexbug board can be discarded.

7 The insulation on the black and white wires must be stripped back slightly to expose the wire inside. Strip approximately 1/8 th of an inch of insulation from the end of the 4 black and white wires. Insulation stripped back approximately 1/8 th of an inch.

8 The top of the spider must be screwed back on using the three screws removed earlier. Before putting the top back on, note which set of wires goes to the "top" motor and which set of wires go to the "bottom" motor. When putting the top back on, be sure to GENTLY pull the wires through the hole created in the top when the insert was removed. "Top" motor Top screw mounts "Bottom" motor Spider body Spider top "Top" motor wires Slot created when removing insert "Bottom" motor wires

9 Note, some pictures may contain blue Hexbug spiders. The color is not relevant to the hack.

10 The EMGRobotics Hexbug Spider No Solder Hacking Kit includes a control board with built-in IR range finder, an "AAA" battery holder and a switch. The 1.5 x 13/16 th inch board uses small screw terminals to secure the motor wires (black and white wires we just stripped) to the board. The screw terminals are the green blocks on the board. EMGRobotics Hexbug Spider No Solder Hacking Kit Includes: AAA battery holder with switch, MSP430G2553 Robot Controller with built-in IR range finder Wire screw terminals (2 screw terminals per green block) MSP430G2553RCBLB

11 The stripped end of the wires are inserted into the front of the green block, while a small flathead screwdriver is used to tighten the screw in the top of the green block. One wire goes into each slot of the green blocks (as shown below). The screws are tightened by turning them clockwise. The screws should be HAND tightened. Do NOT over tighten the screws in the blocks, they will damage the block if tightened too much. The next page explains which wires go into which slots. Insert flathead screwdriver into hole on top of the green block. Insert wires into the front of the green screw blocks. Small 3/64" flathead screwdriver used to tighten screw terminals.

12 The black and white wires go to two different motors in the body of the Hexbug Spider. Each motor gets one black wire and one white wire. These wires MUST be inserted into the correct position in the correct green screw terminal. Each green terminal block connects to one motor; each green terminal block will have a white and black wire. Within the Hexbug Spider is a top motor and a bottom motor, each with a black and white wire. The top motor connects to one green screw block and the bottom motor connects to the other green screw block. Wires to "top" motor Wires to "bottom" motor

13 The battery holder and board have double sided tape on them. Remove the green backing to expose the sticky surface. Mount the battery holder and board on the spider as shown in the picture below.

14 Completed robot with optional programming wires attached.

15 To insert batteries slide open the AAA battery holder and insert the batteries as shown in the diagram embossed in the plastic battery holder. Aiming the IR range sensor This is the most difficult part of building the robot. The IR range sensor has two parts. The clear device is called transmitter, the dark device is called a receiver. The transmitter and receiver have long leads that allow the devices at the end of the leads to be "aimed". Be sure the power switch on the battery holder is OFF. Using a pair of long-nose pliers, bend the leads to the clear device and the dark device aim at the same point. You can create a template to assist in aiming, by drawing a 1.5" diameter circle on a white piece of paper. 2.5" from the EDGE of the circle draw a small circle (dot) about 0.25 inches in diameter and fill it in. Place the robot centered on top of the 2.5" circle. Rotate the robot until the dot is between the transmitter and receiver. While looking down the transmitter, aim it at the dot. While looking down the receiver, aim it at the dot. Be sure none of the transmitter or receiver leads touch each other. This will create a short circuit and damage the board. Before turning on the robot, double check that none of the leads going to the transmitter or receiver are touching each other. Your first attempt at aiming the transmitter and receiver may not work. Aiming is not an exact science and will require some tweaking to get it perfect.

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17 Testing the Robot The EMGRobotics Hexbug Spider No Solder Hacking Kit comes pre-programmed for line following operation. The robot will follow a dark line on a bright surface, for example a black line on a white piece of paper. I use a piece of black electrical tape on my kitchen table. A thick black marker applied to a piece of cardboard will work as well. The line should be at least 0.5 inches wide. Place the robot on top of the black line with the sensors offset to the side of the line as shown in step 1 below. Be sure none of the transmitter or receiver leads touch each other. This will create a short circuit and damage the board. Slide the power switch on the battery holder to "ON". If the "top" and "bottom" motors have been connected to the board correctly, the robot should turn its head counter-clockwise (viewing from top) approximately 180 degrees. It will then turn clockwise until it "sees" the black tape. Finally it will start walking forward following the tape. In the images below the power switch is off, but that is only because I had to freeze the robot to take a picture. For this test, the power switch must be on. Step 1 Place robot as shown, slide switch to "ON". Step 2 Robot rotates CCW 180 deg. to detect line. Step 3 Robot rotates CW to find line. Step 4 Robot walks forward following line. If the robot does not find the line (step 3) and rotates Clock-Wise over the line, the transmitter and receiver may not be aimed correctly. Go back to "Aiming the IR range sensor".

18 Using your Newly Hacked Robot Using your robot is easy. Simply put the robot over the line, oriented as shown in step 1 above. Then slide the switch to the on position. The robot will rotate CCW 180 degrees as shown in step 2. While the robot is rotating, it is using the IR range sensor to measure the distance to the surface. The black tape absorbs the IR energy, making it look like it is far away. The robot basically "sees" the black tape as a gully. The robot records the "depth" of the gully and the "depth" of the surface on either side of the gully. After the robot has measures the "depth" of the gully and the surface around it, the robot uses the information to find the black tape. As shown in step 3, the robot rotates clock-wise until it finds the center of the gully. After finding the center of the gully, the robot will start walking forward as shown in step 4. For Advanced Users You can order the TI Launchpad for $4.30 from: The TI Launchpad is used to program the EMGRobotics MSP430G2553 Robot Controller used in the spider hack kit. The Launchpad connects to the robot controller using 3 wires, and can fully debug and program the robot controller. The TI Launchpad comes with the FREE Code Composer Studio professional C compiler and debugger. Using these tools you can create your program, flash it to the robot controller, and debug your program using breakpoints and stepping as expected from a professional tool. Time spent learning how to use the TI Launchpad and Code Composer Studio can be referenced on your resume. These are professional tools used by electronic manufactures around the world. The source code for the EMGRobotics Hexbug Spider No Solder Hacking Kit is available here:

19 The TI Launchpad plugs into the GND, TST, and RST pins on the EMGRobotics board (debug jumper wires not included). To disable the motors while debugging, remove the indicated jumper. Remove this jumper to disable motors while debugging. RST GND TST

20 EMGRobotics board shipped with No Solder Spider Hack Kit (MSP430G2553RCBLB) MSP430G2553 Function User Connector Description PIN PIN 1 VCC Connected to 3.0V regulator 2 NC 3 RXD/A1 8 UART RXD / IR Range Sensor 2 (RX) 4 TXD/A2 9 UART TXD / IR Range Sensor 3 (RX) 5 A3 USER 2 (IR Transistor) 6 NC 7 P1.5/TA0.0 LB1836M IN2 8 P2.0/TA1.0 LB1836M IN4 9 P2.1/TA1.1 LB1836M IN3 10 GPIO 11 GPIO 10 GPIO / IR Range Sensor 3 (TX) 12 GPIO IR LED 13 NC 14 I2C/A6 7 GPIO / IR Range Sensor 4 (RX) 15 I2C/A7/GPIO 6 GPIO / IR Range Sensor 4 (TX) 16 DEBUG-RST 5 Debug RST 17 DEBUG-TST 4 Debug TST 18 GPIO 3 GPIO / IR Range Sensor 2 (TX) 19 P2.6/TA0.1 LB1836M IN1 20 GND Motor Control Truth Table (IN1=P2.6, IN2=P1.5, IN3=P2.1, IN4=P2.0)

21 Software Personalities Robot Application (main.c) Board Files (boardrcblb.c/boardrcblb.h) Chip Files (EMGRobotics_MSP430G2553.c/EMGRobotics_MSP430G2553.h) The software has been designed to make it simple to modify the behavior of the robot. The robots personality is all coded in main.c. The example code uses a state machine to support four personalities. Changing personalities requires rebuilding the code and re-flashing the board. ROBOT_MODE MODE_TEST MODE_LINE_FOLLOWER MODE_AVOID_OBSTRUCTIONS MODE_ATTACKER Description Special test mode for manufacture testing Follow a black line Roam around avoiding obstructions Roam around, avoid obstructions, attack other robots when found You can change the robots personality by simply changing line 88 in main.c with the constant defined in the table above. main.c line 88 Robot_Mode = MODE_LINE_FOLLOWER; Software Architecture Robot Application (main.c) Board Files (boardrcblb.c/boardrcblb.h) Chip Files (EMGRobotics_MSP430G2553.c/EMGRobotics_MSP430G2553.h) Expanding the functionality of the robot beyond the limitations of the example code is easy using the functions available in the board and chip files. If you program the robot to do something cool, I encourage you to video your robot in action and post it on YouTube. I also encourage you to share your code on

22 Resources You can purchase the EMGRobotics Hexbug Spider No Solder Hacking Kit here: The source code for the EMGRobotics Hexbug Spider No Solder Hacking Kit is available here: