Multiple changes have been made since I last worked on this project.
I changed the microcontroller of choice from Attiny85 to
Atmega328p due to its larger number of I/O.
Transmission protocol change
I chose to use USART for this project. After some research I
realized that the 433 MHz modules are not reliable enough to send a
simple data stream such as varying duty cycles.
For more reliable data transmission it was essential not only to the
use USART but also to send multiple bytes via USART to ensure proper
transmission of data.
Using cheap DIY car kits
Also I decided to invest in cheap car kits that can be assembled
instead of trying to make everything out of cardboard.
Changing method of input
While working with the push buttons I soon realized that they are
unreliable. I even soldered a "button board" together and have still
found that the push buttons give false positives or get
stuck or break easily. Therefore I decided to change the method of input to a
computer keyboard and send various commands through serial.