I made some progress last nights while staying awake until 3-4 AM. I have tried NRF24L01 modules but without success. I have to order new ones, I have’t got any spares. They were working fine last year, I don’t know what happened. So, I decided to add Bluetooth Module (HC-06).
First of all, I was looking for Android App which will be the best for my purpose. Simple app which will be sending data to the car continuously! I didn’t find such an app for controlling car. I found some, but they were horrible, but good for testing. The app I downloaded has joystick and buttons like gamepad. The problem was in joystick. It was just like 8 buttons and the direction you moved with joystick the specific button was sent to the car ONCE. When I released the joystick some another character was sent to the car but also ONCE. That was problem. Why? Because when I lost connection between smartphone and HC-06 the car will still going in the last known direction and car easily run away and be damaged. And so it happened. It fell off the broke rear bumper. Glue, easy fix.
When the car was finished and working I started programming custom Android application. I wanted keep it simple. I added status bar with connect switch, voltage and device name and coefficients. Below the status bar were placed custom made „Analog Sticks“, one vertical, one horizontal giving me a range of -1.0 to +1.0 for better calculations. I will talk about the app itself in the part #3.