“Several years ago I built a LC-Meter based on an open-source design of a “Surprisingly Accurate LC meter” by Phil Rice VK3BHR at http://sites.google.com/site/vk3bhr
Presented here is a modified design based on a Microchip PIC18F14K50 USB Flash Microcontroller which is connected to an Android phone using the On-The-Go (OTG) mode. The phone provides power to the circuitry and an Android Application provides the Graphical-User-Interface (GUI).
The following are the highlights of the design:
- Single PIC18F14K50 microcontroller with USB interface and internal analog comparator
- Simple c-code on the microcontroller implementing a basic frequency counter
- GUI Test code in Qt Creator and Android application using Android Studio
- All calculations carried out in higher level language
- Low power consumption ~ 18 mA at +5V
- Design verified by building a bread-board and engineered unitI wish to acknowledge use of the Usb serial controller for Android v4.5 example code in implementing the OTG connectivity.”