T2W3: Adding Hardware
It seems hard to believe that we are only in the third week of the STEMörgåsbord elective! Last week we finished building the VEX IQ "standard drive base", a four-wheeled remote-controlled robot car, and some students got it driving around using the the remote controller. To get it working requires connecting the VEX IQ robot "brain" to a laptop to update the firmware, which can take a little while to get going. Once your firmware is updated and you can drive the robot around, there are a couple of different options for what to do next: build an autopilot robot, or add your own hardware to the drive base. In future weeks we will learn about programming the robots with our own control code.
Build The Autopilot Robot
You can add some sensors to the "standard drive base" that will let the robot be autonomous and drive itself around as it explores the room. This will be a good starting point for doing our own programming of the robot. Look in the IQ Build Instructions starting on page 32 (steps 102-117) for instructions on building the Autopilot robot. I also have B/W printed versions for each person to keep - it might be easier to pick the right part on the actual-size printouts.
Autopilot Mode
Once you have added the sensors to the base platform and wired them to the robot's brain module, run the built-in autopilot program by:
Press the check mark button to turn on the VEX brain module
Under Programs, select "Demos" and press the check button again
Highlight "Autopilot" and press the check button to start the program
When the autopilot program is running, the robot will drive itself around in different patterns and use the ultrasonic distance sensor to avoid running into obstacles. Touch the "Touch LED" module to change motion modes, indicated by the color of the LED. For more information, see this page on the VEX website:
https://kb.vex.com/hc/en-us/articles/360044274332-Using-Autopilot-Programs-IQ-Brain-1st-gen-
Other VEX IQ Robots
Here is a web page with a bunch of other robot designs:
https://www.vexrobotics.com/iq/downloads/build-instructions#super-kit-1st-gen
Some are for game competitions and others are just for fun!
Add Hardware to the Drive Base
Another option for the base robot is to maintain the wireless drive control but add additional hardware and features. The Driver Control Program can use the extra buttons on the handheld controllers to control additional motors for grabbers, scoops, extra legs - whatever you can think of to customize your robot! The Driver Control Program links sets of buttons on the handheld controller to motors plugged in to specific ports on the brain unit. Here is a chart showing which buttons control motors in which ports:
https://kb.vex.com/hc/en-us/articles/360035592512-Running-Driver-Control-Programs-IQ-Brain-1st-gen-
You can also use VEX IQ bumper switches as limit switches to disable the motors at the ends of the motor travel.
Guide to VEX IQ Modules
Our VEX IQ kits come with a bunch of different electronic modules that we can attach to our robots and wire to the "brain". The VEX IQ software environment has libraries for each motor and sensor that make it easy for us to use the features in our own programs. Here is a guide to the sensor devices we have with descriptions from the VEX Robotics web store.
Smart Motor
The IQ Smart Motor turns the wheels of our standard drive base robot, but is more than just a motor - it has sensors to make sure the robot goes where we tell it.
The Smart Motor does more than just make your wheels spin or arm move. The built in processor, quadrature encoder and current monitor allow for advanced control and feedback through the Robot Brain.
Command speed, direction, time, revolutions and degrees
Mounts directly to VEX IQ structural components with standard connector pins
Encoder resolution is 0.375 degrees
Supports event programming to simplify software
Distance Sensor
The Distance Sensor (1st generation) uses ultrasonic sound waves to measure distance
Measures distance from 50mm to 1m
Continuously measures distance to minimize delays
Supports event programming to simplify software
Touch LED
The Touch LED outputs color and inputs touch
Smart sensor with internal processor and Red, Green, Blue LEDs
Glows in up to 16 million color variations
Constant on, off, or blink at any desired rate
Touch sensor for student interaction with robot and software
Supports event programming to simplify software
Gyro Sensor
The Gyro Sensor (1st generation) measures turn rate and calculates direction
Measures rotation rate at up to 500 degrees/second
Continuously calculates robot direction
Supports event programming to simplify software
Measure angle at up to 3,000 times/second
Bumper Switch
The Bumper Switch gives your robot the sense of touch
Low force switch can detect light touch
Use to detect walls or limit an arms motion
Supports event programming to simplify software
Color Sensor
The Color Sensor detects the color of objects
Measures simple color
Measures color hue
Measures independent Red, Green, and Blue in 256 levels each
Measure ambient light level
Supports event programming to simplify software
Robot of the Week
Each week I will find a quick video of a different robot companions, to help inspire your own creations. This week's robot is Keepon, the dancing robot from researchers Hideki Kozima and Marek Michalowski: