IoT Connected MSP430 Car

16 May 2018

THE PROJECT

The plan for this project was to build a car which could be navigated via a WiFi connection and follow a black line. This blog post will go over the final product. We will be looking at both the hardware and software which was used in this project.

BILL OF MATERIALS

MSP430FR5994
RF TXRX MODULE WIFI CHIP ANT
CUSTOM CONTROL BOARD
120:1 MINI PLASTIC GEARMOTOR OFFSET 2mm SPLINE OUTPUT (2)
LCD MODULE 4X10 WH BKGRND RFLT 2.6mm

THE CODE

FIND THE ENTIRE CODE HERE

INIT_ADC

This is the code that initializes the MSP430's ADC.

LCD.r43

This is a precompiled binary given to us.

blackline

This code is very basic. It uses the IR emitter and detectors to see where the car is on the blackline. If only the right one is on, it is veering too far left and needs to turn right. Similarly, if only the left is on it is veering too far right and needs to turn left. Otherwise (being on black or white) it will go straight. I had used PWMs for the motions, but as the batteries got low, these no longer worked, so I just used turning on and off the motors to move.

button_change

This code simply uses debouncing in order to detect a button push. It also sets the backlight of the LCD to be off, but I have it off by default, so in reality lines 45 and 60 do not do anything.

clocks

This code initializes the MSP430's clocks so that we can set up timers later.

convert

This code takes in and converts the input of the MSP430's ADC values so that they are useable (IR Left and Right Detector, Thumbwheel, etc.). This also contains a function that converts the hex value in memory (used when sending commands over WiFi) into BCD and then to ASCII.

functions

Header file containing all function names.

init

Contains the initial conditions that are used by all other files.

interrupts_timers

This code contains the interrupts for the timers that we set up, as well as the ADC interrupt.

led

This code turns on the two LEDs on the MSP430.

macros

Header file that contains all of the macros used and their corresponding values.

main

This code is where all other functions are called, and contains the while loop which process incoming commands, displays command info on the LED display, and calls the required process based on the incoming command.

motors

As mentioned earlier, this was originally done with PWMs, however, when the battery voltage was too low, this no longer worked. This code now contains the turning on and off the motors directly (both in the forward and reverse directions).

ports

This code contains the initialization of all the port pins.

serial

This code handled the serial data. It handled both USB and WiFi TX and RX buffers, which were used to decipher the commands being sent, as well as debugging.

switch

This code initialized Button 1 and Button 2 on the MSP430 as switches.

system

This code contains the system configurations.

timers

This code initialized the timers to the desired frequency using the MSP430's clocks.

Currently, I do not have the car to take videos of, but these will be added to this post in a few weeks when I have access to the vehicle again (enjoy the few I do have though!)