Here's what you need for this project:
- One (1) iRobot Create
- Three (3) DB9/D-Sub Male Connectors (9 Pin) - You can pick these up at Radio Shack
- One (1) WiFi Signal Detector from IO Gear - Here @ Radio Shack
- Soldering Iron
- Flux/Soldering Paste
- Takes in WiFi data from four spots, North (up), West (left), South (down), and East (right).
- Analyzes data, moves towards best wireless direction.
- Continues to get WiFi data and move towards the best direction.
Please "+" this if you like it!
#Featured on Make:Blog!
Step 1: Crack Open Your Wifi Detector
Step 2: Solder the LEDs to the DB9 Connectors
To begin, secure the WiFi detector's circuit board in something like the "Helping Hands" set. Then, solder one end of a DIFFERENT color wire to each of the LEDs. We will be soldering to the end of the LED that is NOT connected to the common voltage supply. (See picture)
Left DB9 Connector
The topmost LED (the one soldered sideways instead of up) connects to Pin 1 of the DB9 connector. The next one down connects to Pin 2 of the DB9 connector. A wire is also soldered onto Pin 5 of this DB9 connector, to be connected to Pin 5 on the center DB9 connector.
Center DB9 Connector
The middle LED is soldered onto Pin 1 of the DB9 connector, and the one below it connects to the second Pin of the DB9. The wire from Pin 5 on the left DB9 connector is soldered onto Pin 5 of this DB9.
Right DB9 Connector
A wire is soldered from Pin 4 on the DB9 to the positive end on the WiFi detector. Another wire connects from Pin 9 to the negative end on the WiFi detector.
Step 3: Solder the Jumper Wires
Using the multimeter's continuity test (the one with the beep!), it was found that the pins going left to right needed to be soldered together in order to bypass the switch.
We got some shielded wire (don't want to mess up the other components by accident!) and soldered onto the pins. See the picture if you're having trouble understanding.
Step 4: Coding
Download these files and open "Programmer's Notepad". Go to "File -> New -> Project" and name it what you wish (search in our case). Then, right click search in the left column and hit "Add Files". Then, find where you saved the attached files "search.c", "makefile", and "oi.h". Go to "Tools -> Make All". This compiles the code so the robot can read it. After it completes (look at the output bar on the bottom of the screen), plug in your iRobot Create and turn the Command Module on. Go to "Tools -> Program". This programs the on board microchip in the module. After this finishes, unplug, turn the Command Module off, and then turn it on again and wait. The program will then start.
This program heavily utilizes the demo code provided by the iRobot demo files. A timer and the bump sensor data are based on the SIGNAL interrupt. The rest of the code is divided into various functions which are hopefully not too hard to read. The calculation we used to determine the optimal direction did not use trig functions, but rather, a less intense approximation calculation.
Step 5: Making A Nicer Looking Product
The case was test fitted and marked with a pencil. A straight file was used to make the holes (see pic three). The key part was to make sure no wires were pinching when the case closed. For the top half, we made four rectangular indentions, and for the bottom, we filed it sown in a straight line. See the picture.