Core Interface, Scanning & Navigation

Today I worked on turning Project EVE from a bundle of individual hardware tests into an actual working system

Part 1: Interface

I built the main menu for the OLED and added two-button navigation.

The MOVE button switches between:

• SCAN
• STATUS

The Select button opens whichever option is highlighted with an arrow. I also made Select behave differently depending on EVE’s current mode. From SCAN or STATUS, pressing Select returns EVE to the main menu. This taught me how variables like mode and menuChoice can control the behavior of my embedded system.

Part 2: Scanning

The scanning system now uses an ESP32, servo, and ultrasonic sensor altogether. The servo sweeps between 30° and 150°, then reverses direction and sweeps back. At each position, the ultrasonic sensor measures the distance. The OLED displays the current servo angle and measured distance. I also changed the scanning system again to use milliseconds instead of blocking the program with long delays.

Part 3: Status System

I redesigned the STATUS screen to show basic info on the system:

• SYS: ONLINE
• SERVO: READY
• SONAR: READY

It’s still a very simple screen but gives EVE a place to eventually display more useful info.

Part 4: Problems & Learning

One of the biggest problems I ran into was understanding how the buttons and menu variables worked together.

I initially had the menu switching back immediately because my if statements were structured incorrectly. Fixing this taught me why else if matters and how changing a variable can affect the next condition.

Part 5: What’s Next?

The next goal is to make the scanner more intelligent on EVE. Right now, EVE can measure distances at different angles, but doesn’t understand the measurements yet.

Next I want to work toward:

• Putting the ultrasonic sensor on the servo
• Organizing the wiring
• Storing scanner measurements
• Detecting nearby objects & indicating them on the OLED
• Improving the interface for the scanner
• Later on determining where an object is located based on their angle and distance

After that, I’ll continue developing the hardware and physical design of EVE. This is still an early version of EVE, but the core system is starting to come together.