Remote robot using STM32, ESP8266 and Android
Video Tutorial: https://www.youtube.com/watch?v=vzHLPQ25O1Q

• Use WASD to move around
• QWERTY digits (1,2,3...,9,0) to set the speed (power) from 10% (1) to 100% (0)
• R to toggle Driving Assintance
• L to toggle LED Lights

STM32 Pinout:

[STM32 C code] You have to change your WiFi SSID credentials in "myLibrary.h":

#define WiFi_Credentials	"AT+CWJAP=\"WiFiSSID\",\"WiFiPASSWORD\"\r\n"

[STM32 C code] Calculating the battery percentage:

• You have to list all voltege regulators and components that are connected directly to the battery
• Find out their lowest voltage needed to run (or regulate) properly
• The highest low voltage will be a 0% of the battery for you (in this case minVoltage = 6.0V)
• The 2 cell Lithium battery has voltage range 6.0V to 8.4V (voltageRange = 2.4V)
• Estimate the voltage drop due to current load (voltageDrop = 0.05V)
• Formula: percentage = ((batteryVoltage - minVoltage) / (voltageRange - voltageDrop))*100.0f;

void calculateBattery()
{
	percent = ((batteryVoltage-6.0f) / 2.35f)*100.0f;
	if(percent > 100.0f)
		percent = 100.0f;
}

[Java Desktop App] Also you have to change the IP addresses in "IP_STM32.txt" and "AndroidIP.txt" files,
which is automatically generated if does not exist and the JAR app is launched.

Use a DDNS service such as No-IP to create a hostname

Add DDNS credentials to your router

Reserve IP address of your IoT device (make it static, so it won't change over time)

Setup a port forwarding rules for STM32 (ESP8266) and Android too.

Now you can access the robot from anywhere.

https://github.com/viktorvano/STM32F103C8T6_HC-SR04