Lab Experiment 1: The LPC 2148 Education Board

Transcription

1 Lab Experiment 1: The LPC 2148 Education Board 1 Introduction The aim of this course ECE 425L is to help you understand and utilize the functionalities of ARM7TDMI LPC2148 microcontroller. To do that, we use a circuit board, where the ARM microcontroller resides on, to help us configure and communicate with the microcontroller. The circuit board we are using in this lab is the LPC2148 Education board. This lab experiment contains a tutorial to introduce students to the LPC 2148 Education board ( from Embedded Artists. Emphases will be placed on learning components on the board, and connecting the board to a computer to run a test program. 2 Lab Preparation 2.1 LAB PARTNER As mentioned in the syllabus, you will be working with a partner during these experiments. When you arrive at the lab for lab experiment 2, make sure you sign in with your partner. 2.2 OSCILLOSCOPE You should already know how to use an oscilloscope from previous courses. For this lab, all that you need to do is to take a quick look at the oscilloscope that is part of your Laboratory environment. Take the time to identify the two main input channels and the various controls associated with them. In particular, locate the scale control and the time base control. You will be using these controls in later experiments. 3 Lab Tasks 3.1 ONBOARD PERIPHERALS The board used in this lab course is the Embedded Artists LPC2148 Education Board with NXP s ARM7TDMI LPC2148 microcontroller. You need to identify the following onboard components, and check with next to the numbering of the ones that you could find. (1) The NXP LPC2148 Microcontroller Chip Note: What are on the chip? CPU core: ARM7TDMI-S On-chip Memory: 512 KByte program Flash: 0 0x8, KByte RAM: 0x4000,0000 0x4000,7FFF Pin Number: 64 (illustrated in Figure 1) Many more: A/D, D/A, timer, interrupts, UART, 1

2 (2) Crystal Oscillator: MHz (Phase-locked loop (PLL) multiplies frequency with five; 5 x 12 MHz = 60 MHz is the maximum execution speed) (3) Character LCD (4) 8 8 LED matrix (connected to the SPI of the LPC 2148) (5) 8 LEDs (connected to GPIO pins P0.9-P0.15) (6) Push-button (connected to the interrupt input pin P0.14 of the LPC 2148) (7) Reset Push-button Figure 1. LPC pin package (8) Joystick-switch (connected to 5 pins; 4 directions and one center push-down switch) (9) RGB-LED (red-green-blue, connected to PWM pins P0.7-P0.9) (10) Temperature Sensor (LM 75, connected to I2C pins) (11) MMC/SD memory card interface (connected to the SPI of the LPC 2148) (12) Step motor (with a propeller mounted on) (13) Interface to Max Stream XBee module (note that XBee module is not mounted) 2

3 (14) Speaker with volume control (connected to analog output P0.25) (15) Two potentiometers (connected to analog input pins P0.28 and P0.29) The following components are connecters: (16) Mini-B USB connector to UART#0 UART-to-serial bridge (17) Mini-B USB connector to LPC2148 device interface (18) JTAG interface (19) 2.1 mm power supply connector (20) 50 pin expansion connector (most LPC2148 I/O pins are available on connector) Note: The 50 pin expansion connector, with most LPC2148 I/O pins available, allows the LPC2148 Education Board to be expanded with new and exciting hardware. The following signals are available on the expansion connector (see Figure 2 for pin assignment): P0.0 - P0.23, P0.25, P0.28-P0.31 P P1.25 Reset Vref Vbat Power; VCC (+3.3V), GND, and Vin (+5V) 3.2 TEST PROGRAM The LPC2148 Education Board comes preloaded with a test program. This program can be used to verify that the board operates correctly. In this experiment, you will power up the education board, download the test program to your board, and execute the program. To this end, a Flash programmer software called FlashMagic is used, and the file name of the test program is testprogram_lpc2148_edu_v3_0.hex. Follow the procedure below. A. Follow the steps below to load the test program. (1) Connect the mini-b USB connecter (UART#0) to a USB port on your computer, which will power up the board. (2) Click on Start in the lower left corner of your PC screen, followed by clicking All programs to find My computer. Right click on My computer, and select and click Properties on the drop-down menu. (3) In the System Properties window, click on Device Manage, as shown in Figure 3. (4) The new COM port (USB Serial Port) will be listed under the Ports list, as illustrated in Figure 4. (5) Right-click on the new USB Serial Port and select Properties. Set bits per second, 8 data bits, none parity, 1 stop bit, and none flow control, as illustrated in Figure 5. 3

4 Figure 2. Expansion Connector Figure 3. System Properties Window. 4

5 Figure 4. Device Manager Window. Figure 5. USB Serial Port Properties. 5

6 (6) Open the program named FlashMagic from the program list of the Windows. Select device LPC2148, the right COM port read from Device Manager, Baud Rate 38400, Interface None, and Oscillator 12MHz. In step 2 box, choose erase blocks used by HEX file. Select HEX file in step 3, and click on Start. The FlashMagic window is shown in Figure 6. (7) The program will be downloaded to the on-chip FLASH memory when Finished is displayed in the status box at the bottom of the window. Figure 6. Flash Magic Interface Window. B. Follow the steps below to run the test program. (1) Push the reset button. (2) Hear the startup sound from the speaker (adjust volume control just beside the speaker if a sound is not heard). (3) Watch the running-one on the individual LEDs. (4) After that a test loop is entered: Printed message on the LCD and flashing of backlight Scrolled message on 8x8 LED matrix Dimming of RGB-LEDs Running the step motor forward and backward 6

7 4. Lab Requirement (1) No pre-lab report is required for this experiment. (2) No lab report is necessary for this experiment. (3) You must sign in with your partner at the beginning of the lab, and sign out before you leave the lab. (4) Check with the lab instructor and answer any questions your instructor may ask, before leaving the lab. (5) Always disconnect the board from the computer, and clear up the bench top, before you leave. 7