Chapter 6

Demo Setup

WARNING

This circuit is powered directly from the mains voltage supply. It is dangerous to touch any part of the circuit. When working with such circuits, do not connect any scope or development system without using an isolation transformer.

6.1 Hardware Setup

This section describes the setup and operation of the light ballast demo. Since the tubes are an integral part of the application, the whole demo system is considered. A photograph of the demo is shown in Figure 1-1. No hardware setup is required to run the application. If you wish to debug the application using Monitor Mode, you must take apart the plexi glass, disconnect the light ballast from the mains supply, and connect the Monitor Mode connector to header JP5. In this case the light ballast must be supplied with a DC-bus voltage.

NOTE

The dimming level potentiometer must be set to the correct position for entry to Monitor Mode (pin PTA1 must be at logic level 1).

The dimming level potentiometer is connected to the JP2 header.

6.2 Software Setup

6.2.1 Required Software Tools

Metrowerks CodeWarrior for MC68HC08 microcontrollers version 3.0, or later, is required for developing the application.

6.2.2 Building and Uploading the Application

The application software is delivered as DLB-LB8-001.mcp project file (see Reference [5]) with C-sources and header files.To build the application software, open the DLB-LB8-001.mcpproject file. Set definition lines at the beginning of “dlb_program_config.h” file as described in 5.6.1 System Setup Definitions. Then execute the Make command in the Project menu. This will build and link the application and all required Metrowerks libraries. Using Metrowerks CodeWarrior, the executable s19 file will be created. There are six possible versions of s19 file, which are also delivered as part of the software package.

The following SW versions are available:

•Hysteresis current control mode for 50 Hz— Hyst50Hz.s19

•Hysteresis current control mode for 60 Hz — Hyst60Hz.s19

•Discontinuous conduction mode for 50 Hz and for input voltage lower than half of DC-Bus voltage

— DCM50HzL.s19

Dimmable Light Ballast with Power Factor Correction, Rev. 1

Freescale Semiconductor

57

Page 56 Page 58
Page 57
Image 57
Freescale Semiconductor M68HC08 manual Hardware Setup, Software Setup, Required Software Tools
Page 56 Page 58

M68HC08 specifications

Freescale Semiconductor, known for its innovative solutions in the field of embedded systems, developed the M68HC08 microcontroller family, which includes the MC68HC908QT2. This 8-bit microcontroller is engineered to meet the demands of diverse applications, including automotive, industrial, and consumer electronics.

The MC68HC908QT2 is designed around Freescale’s M68HC08 core, which is renowned for its efficient and reliable performance. This microcontroller integrates a powerful instruction set, enabling developers to create high-performance applications with relatively low power consumption. The device operates at a clock frequency of up to 3 MHz, which is adequate for various control tasks.

One of the key features of the MC68HC908QT2 is its memory architecture. It includes a 2 KB Flash memory for program storage, representing a significant advantage for developers requiring non-volatile memory. Additionally, it encompasses 128 bytes of EEPROM memory, allowing for data retention even after power loss. The microcontroller also has 256 bytes of RAM for efficient data manipulation during operation.

In terms of input/output capabilities, the MC68HC908QT2 supports a variety of interfacing options. The microcontroller features up to 20 general-purpose I/O pins for flexibility in connecting with peripheral devices. Additionally, it provides multiple analog-to-digital converters (ADC) and timers that facilitate efficient analog signal processing and precise control through timing functions.

The architecture of the MC68HC908QT2 also incorporates sophisticated on-chip peripherals, enhancing its functionality. These peripherals include PWM (Pulse Width Modulation) outputs, which are essential for applications requiring motor control and other precise duty cycle processes. The integrated watchdog timer ensures reliable operation by resetting the system in the event of an application failure.

Moreover, the MC68HC908QT2 is equipped with an efficient power management system, enabling operation in a low-power mode, ideal for battery-powered applications. This microcontroller is packaged in a compact 28-pin dual in-line package (DIP), making it suitable for space-constrained designs.

In summary, the Freescale Semiconductor MC68HC908QT2 microcontroller is distinguished by its robust performance, extensive memory options, and versatile I/O capabilities. Its advanced features, including built-in timers, ADC, and a power management system, make it an exceptional choice for developers seeking to implement reliable and efficient embedded solutions. With its comprehensive architecture, the MC68HC908QT2 remains a popular choice in the landscape of 8-bit microcontrollers.
Top Page Image Contents