AME 3623: Project 5: Hovercraft Motor Control

For this project, you are expanding what you learned in project 4 to your Hovercraft. Specifically, you will be connecting a total of three H-bridges to your circuit and wiring one to each of the fans that are located between the lower and upper decks.

All components of the project are due by Tuesday, March 30th at 5 pm.
Groups are the same as for project 1.
Discussion within groups is fine.
Discussion across groups may not be about the specifics of the solution (general programming/circuit issues are fine to discuss).

At the end of this project, you should be able to:

control the magnitude and direction of all three fans separately,
use a Finite State Machine to test these fans.

Component 1: Hardware and Circuit

See the initial hovercraft wiring guide to set up your breadboards, Teensy, and hovercraft wiring.
Connect two H-bridge boards to one of your breadboards. It is best to place these next to each other, as far from the Teensy as possible. These two boards can be either dual h-bridge boards, or one dual and one single h-bridge board.
Motor battery power is brought from the lower deck using two pairs of thick red/black wire pairs. Connect one pair to the battery input of each of the H-bridge boards. Make sure that you properly match the negative side of the battery with the negative side of the board, and vice versa. And, do this wiring before connecting the battery.
Connect each of the motors to one of the H-bridge outputs. These wires are pairs leading directly from the motors attached to the fans.
As in project 4, connect the digital side of the H-bridges to your breadboard circuit. These connections include +5V power, ground, enable A/B, PWM.

Component 2: Software

Implement the following function:
void set_motors(float val[3])
This function sets the magnitude and direction of thrust for each of the three fans. Note that a positive val must correspond to air flow through the "natural" direction of the duct (the fan pushes air over the motor).
Within this function, declare the following constant:
```
       const float negative_gain[3] = {1.0, 1.0, 1.0};
```
If the incoming val is negative, then it should first be multiplied by the corresponding negative_gain before bounding and conversion to an integer. We will use this in the next project to properly balance the efficient and inefficient directions of air flow.
Implement a new finite state machine in fsm_step(). This state machine will:
1. Wait for the switch to be pressed.
2. Ramp the left motor up to 25% duty cycle
3. Ramp the right motor up to 25% duty cycle
4. Ramp the rear motor up to 25% duty cycle
5. Ramp all three motors down to -25% duty cycle (together)
6. Ramp the left motor up to 0% duty cycle
7. Ramp the right motor up to 0% duty cycle
8. Ramp the rear motor up to 0% duty cycle
9. Return to the start state

What to Hand In

All components of the project are due by Tuesday, March 30th at 5pm

Demonstration/Code Review: All group members must be present. The demonstration must be completed by Friday, April 2nd.
Check in the following to your project 5 area of your Dropbox:
- Documented code: See the project 1 specification for detailed documentation requirements.
Personal report: Catme will request that you fill out a survey about the project. These must be completed by April 2nd in order to receive credit for the project.

Grading

Project lead credit:

Each person must be the primary integrator of circuits and code for two projects over the course of the semester.

For a successful project, we expect:

A properly configured circuit
- H-bridge installed correctly
- Switch installed correctly
Properly written software
- Function that sets the motor direction and magnitude for all motors
- Finite State Machine implementation
Properly documented code
- Project-level documentation at the top of the ino file: name and group number, date and project number
- Function-level documentation above the function definition. Include an abstract description of what the function does; a list of the names, types and units associated with each parameter and return value; and the effects that the function has on the processor or connected components.
- In-line documentation inside of functions: individual lines or small groups of lines have an English description that describes logically what the code is doing

andrewhfagg -- gmail.com

Last modified: Sat Mar 27 15:29:00 2021