First and foremost, be creative!! Below are just a few inspirational ideas. Option #1 - I cut-down (miter saw) a 4-position TWR-ELEVATOR to make this 2-position design. With the intent of having two boards mounted 1) TWR-PROTO and 2) MCU of choice (K40). If cutting PCB's with power tools is not your thing, you can buy a 2-position Tower Elevator here: http://wavenumber.net/twr-elev-2/ I just marked the holes on the back supportand drilled holes into the TWR-PROTO, a few stand-offs and viola! Option #2 - This option requires the removal of the rear spring. I am not sure how much value that spring honestly provides since most of the track is nice and flat. If you have a newer TWR-ELEVATOR you usually find some way to mount it to the screw holes with some form of L-Bracket. If you have an older TWR-ELEVATOR you can drill a hole in the Secondary Elevator (less PCB traces to worry about) and then mount it to the chassis with a L-Bracket. Option #3 - Check out this gallery of images: https://plus.google.com/u/0/photos/106056936857240793028/albums/5598207628299505201
Depending on which MCU Devlopment board you have chosen, you will need to figure out a way to mount this to the chassis. I have seen everything from cardboard, to aluminum, to wood. Below is a template complete with CAD drawings to mount the Qorivva TRK-MPC5604B board and the Motor Board onto the chassis. We use plexiglass for ours, but any other millable material is appropriate. The large hole in the middle is for cables from the servo. We attach the board to the car using the plastic standoffs (you will need them 55 mm long, so in our case, we used the combination of 40 + 15 mm) - see an example (SOS code 10260). To attach both the processor and interface boards the simillar 5mm plastic standoffs were used. Preview (.pdf) CAD file (.dxf)
This page will guide you through the attachment of the servo to the Freescale Cup chassis. The servo steers the vehicle and is controlled using Pulse-width modulation . Video Tutorial (no sound): Step-by-Step: (Click any image to enlarge) Servo Plate Inside the kit are various mounting options for different servo manufacturers. Look for the bushing of the servo that you are using. You will need the three pieces shown below. You will screw this into the servo. Pieces are notched, so assembly is straight forward. Remove the screw and black servo plate. Mount the yellow servo plate assembly to the servo as shown below. Make sure to add the small yellow washer (pictured below) in between the servo plate and the screw. Tighten well, a servo produces a good amount of torque and will slip if not tight. Steering Bar Assembly Assemble the short arm. Assemble the long arm. Putting the Two Together Attach the short arm to the yellow bracket. First, insert the bearing into the control arm. This allows the joint to flex and move. Screw this assembly into the servo plate. Attach the long arm to the yellow bracket. Mounting the Servo Motor Attach the motor mount blocks to the back of the servo on both sides. Screw in the attachment blocks from the bottom of the car. Words of Wisdom Be sure to have servo motor in the 0 degree position before securing the control arms. Failure to do so will result in not being utilize the full range of motion. Do not change the position of the steering servomotor by hand. The position of the steering servomotor should be changed through electrical input only. Don’t move the steering servo motor beyond the maximum limit of the movement and this will damage the servo motor
Assembly Of The Freescale Cup Car Chassis Before you start building your program for your car, It would be better if you can assemble your car chassis first. With your car correctly assembled, you can easily test it with your different programs in the later tutorials. The followings are all the tutorials about car chassis assembly. A step-by-step car chassis assembly manual & hints (pub) (PDF) Servo and steering assembly directions DIY Board mounting template for the TRK-MPC5604B DIY Board mounting template for the Tower System Board mounting suggestions for the FRDM-KL25Z with shield DIY Camera Mounts Wiring connections for the TRK-MPC5604B Hints and notes to chassis assembly Freescale Cup Innovation Challenge EMEA Model B car assembly file in attachment below Exploded Assembly Diagrams Chassis Build Directions [PPT] Original Manufacturer Directions [PDF]
Getting Started with the Freescale Cup How to achieve the goal of creating an autonomous vehicle that quickly navigates around a track? Before continuing with this tutorial, students should take the time to choose which Freescale Microcontroller your team is going to use. The Introduction to Freescale Cup Training article has some details about how to choose your microcontroller. Although the concepts and end results are similar no matter which microcontroller you decide to utilize, much of the software implementation details will differ. What is a Microcontroller? For information on what a microcontroller is head to the microcontrollers article. Getting Started - Learn to Program a microcontroller First off, you are going to need to know C programming. For a crash-course head to c-programming-for-embedded-systems. The classic first application to learn how to program a microcontroller is to get through the process of Blinking an LED. This wiki contains a tutorial for each of the Cup microprocessors which simplifies the process of setting up the evaluation board, installing the Integrated Development Environment, and programming the board with a simple set of software which blinks a LED. The Blink a LED tutorial is the first of 4 tutorials designed to familiarize students with the process of designing a cup car. These four tutorials will introduce students to many of the fundamentals of robotics, the software used to control the locomotion and sensors on an autonomous line following vehicle, and provide example code which help simplify the process of creating a competitive entry in the Freescale Cup. Here is an outline of the Basic Microcontroller Programming Tutorial: Read the microcontroller article Choose a microcontroller Set up the development environment Set up the microcontroller evaluation board Program A LED move to the next tutorial…
Overview: The NXP Cup is a global competition where student teams build, program, and race a model car around a track for speed. The fastest car to complete the trac k without derailing, wins. The creation of this autonomous car requires: Embedded software programming and basic circuit creation using NXP parts included in the entry kit Students to create motor control hardware and software to propel and steer their intelligent car Students must also interface to a camera to navigate the car through the race course by following the guide line. This competition lends itself well to use in senior design/capstone project courses. The contest time frame can fit within the average 3-4 month semester. Most development work can be done easily within that timeline. History: The NXP Cup Challenge is a collaborative, competitive, and hands-on way for students to learn about embedded systems and control. The NXP Cup, formerly known as the Smart Car Race began in 2003 in Korea at Hanyang University hosting 80 teams of students. Since that time the competition has spread to China, India, Malaysia, Latin America, North America, and most recently Europe in 2012, impacting more than 500 schools and 15,000 students a year. In 2010 it took the name of the Freescale Cup followed by NXP Cup after the most recent merger in December 2015.