Smart charger

Abstract

"USB power" has been widely used to charge electronic devices, such as mobile phones. To increase the power level for different applications and objectives, such as shortening the charging time of mobile charges, different charging standards, so-called "Fast Charge", have been proposed. They include Qualcomm Quick Charge (QC), MediaTek Pump Express Plus (PEP), USB Battery Charging (BC), and USB Type-C with USB Power Delivery (PD). As they are of different protocols and operating at different power and voltage levels, there exist compatibility problems. In other words, the mobile device must have the specific "fast charge" protocol before it can be powered or charged by the "special" USB port. The objective of this project is to develop a unified USB port, acting as an interface that can support abovementioned "fast charge" standards and a "smart USB" technology, which is developed by the City University of Hong Kong. The architecture of the USB port developed, named as "Smart Charger", is composed of an ARM-based embed system and a high-power DC-to-DC converter with adjustable output voltage. The maximum power output is 100W, which is sufficient for nowadays and upcoming devices. Such unique feature of allowing different "fast charge" protocols is believed to provides consumers and industry with a new perspective on the charging philosophy. The scope of work of this project consists of two main parts: 1. Hardware design - The entire circuit schematics consist of an ARM-based embedded system, a high-power DC-to-DC voltage converter, a microcontroller, and a Bluetooth module; 2. Software design - The software can handle various kinds of charging methods, allowing "Fast Charge" and general charging modes. It can handle protocols for i. "Battery Charging" v1.2 - adopted by USB technology. ii. Quick Charge – adopted by Qualcomm iii. Pump Express Plus – adopted by MediaTek iv. USB Power Delivery 2.0 – adopted by USB technology.