AGH University of Science and Technology Cracow Department of Electronics

Transcription

1 AGH University of Science and Technology Cracow Department of Electronics Microprocessors laboratory Tutorial A Using Arduino UNO for laboratory tutorials Author: Paweł Russek ver. 02/02/16 1/12

2 1. Introduction 1.1. Objective The main goal of this tutorial is to introduce can it is possible to use the Arduino UNO platform to complete laboratory tutorials. All laboratory exercises were developed for the ZL3AVR development board but you can easily replace with Arduino UNO. Arduino UNO is very popular and very cheap. Further, you do not need an additional hardware programmer to download your program to Arduino, as it is in ZL3AVR case. All you need is Arduino UNO board and a small pheripherial circuits that you can prepare on your own. If you are ready to make a small effort and prepare the Arduino UNO based DIY kit for yourself, go ahead with this tutorial. Later, you will see how it pays as you will be able to prepare your laboratory exercises and project at home Prerequisites Devices and components PC with Atmel Studio 6.x and Arduino software. This tutorial was prepared using 6.0 version Arduino UNO board with USB cable (type male A to male B) Peripherals board. You can use either breadboard, universal PCB (approx cm) or printed circuit. Printed circuit Eagle design file is provided with this tutorial Electronics components according to the list: 1. LED 3mm red (or other colours) 9 pieces Impulse diode 1N pieces 3. 7 segment 4 digit display common anode 0,56'' 1 piece 4. PNP transistor BC557 (TO92) 4 pieces 5a. Resistor 330 ohm 0.25W 8 pieces 5b. Resistor 470 ohm 0.25W 9 pieces 5.c Resistor 10k ohm 0.25W 4 pieces 6. Micro switch 6x6 16 pieces 7a. Female Header 1x8 3 pieces 7b. Female Header 1x5 2 pieces 8a. Pin header 1x1 1 piece 8b. Pin header 1x2 1 piece Breadboard jumper wires Skills Knowledge of AVR ATMega32 hardware architecture. Fundamental AVR assembly programming skills. Basic knowledge and understanding of C language constructs. 2/12

3 2. Arduino UNO board and Atmega320P microcontroller Arduino is an open-source prototyping platform. Arduino boards are able to read inputs - light on a sensor, a finger on a button, and turn it into an output - activating a motor, turning on an LED, publishing something online. Read more about Arduino project at Arduino UNO is one of the available Arduino boards. It is intended to be programmed with the Arduino programming language but its software can be also developed with Atmel Studio with assembly or C languages. The hearth of Arduino UNO is the ATmega328P of Atmel ATmega family of microcontrollers. What is important here, the ATmega328P internal architecture is very similar to our laboratory ATmega32 chip. Small program changes are required to move from ATmega32 to ATMega328P. For example, Atmega32 has four 8-bit ports: PortA(0..7), PortB(0..7), PortC(0..7), and PortD(0..7). Atmega328P provides one 8-bit port and two 6-bit ports: PortD(0..7), PortC(0..5), PortB(0..5). Atmega328P is tiny but a skilful student will be able to fit all laboratory exercises. The ports of ATmega328 are available as Arduino Input/Output signals. Please refer to Arduino schematic or check Table 1 to find proper microcontroller's Port to Arduino IO mapping. Table 1. Arduino IO to ATmega328P mapping Amega320P PortD (0..7) PortC (0..5) PortB (0..5) Arduino UNO IO (0..7) A (0..5) IO (8..13) Figure 1. The ATmega328P part of Arduino schematic 3/12 Figure 2. Arduino UNO board and its important connections

4 Figure 1 presents a schematic of the part of the Arduino board that contains Atmega328P. Figure 2 is an Arduino UNO picture with its connections highlighted. Figure 1 and Figure 2 are given for your later reference. 3. The peripheral board Arduino UNO needs a peripheral shield board to act. There is a variety of shields available but you need a customized that fit Microprocessors Technique Laboratory. The shields usually sits on the top of the Arduino boards but, unfortunately, the size of a standard shield PCB is too small to accommodate peripherals that are required for the laboratory purpose. The schematic of MT Lab extension board is given in Figure 3. You will find the connection headers, leds, led 7-segment display, keyboard and button-pressed sensing circuit. Figure 3: A schematic of MT Lab Arduino extension board 4/12

5 3.1. Connection headers JP1 The JP1 shunt is used to convert 4x4 matrix keyboard to 4 push button interface. If it is closed, switches S1, S2, S3, S4 can be connected directly to the microcontroller's port pins via the C1, C2, C3, and C4 signals and sensed immediately. When it is open micro swich matrix form a keyboard which requires a special procedure to detect a pressed button (see laboratory tutorials for details). JP2 The JP2 pin can be used as a source of logical signal (active low) to detect a button press event on the matrix keyboard. JP3 The JP2 header is a LED connector. Apply high voltage signal to light a selected LED. JP4 The JP2 header is a 4x4 matrix keyboard connector. The C1, C2, C3, and C4 signals are connected to the matrix columns and R1, R2, R3, and R4 are connected to matrix rows. To detect active column, apply low voltage signal to R(1..4) and pull-up C(1..4) with internal microcontroler's ports resistors. To detect active rew, apply low voltage signal to C(1..4) and pull-up R(1..4) with internal microcontroller's ports resistors. When the row and column is detected the button is known. JP5 The JP2 header is 7-segment display cathodes connector. Apply low voltage to light a corresponding segment for an active digit. See also the JP6 description. JP6 The JP2 header is 7-segment display common anodes connector. Apply low voltage to actvate a corresponding digit. See also the JP5 description. JP7 The JP7 header is a power supply for the board. You usually connect 'VCC' to the '5V' power pin of Arduino, and 'GND' to the 'GND' pin of Arduino The PCB of the peripheral board It is possible to create a peripheral circuit given in Figure 3 using a breadboard or a universal PCB, however, for the convenience a printed circuit was designed and provided for this tutorial. The picture of the proposed PCB for the peripheral board is given in Figure 4. Figure 4: A PCB for the pheripheral board 5/12

6 4. Let's do some programming! Beginners usually start with some 'Hello word' program in a new programming environment. In the world of microcontrollers the 'Hello word' can be a led blinking application. We will message the Hello word string as a led blinking in the morse code. Message string Hello word Morse code / The hardware preparation step 1. Connect your Arduino UNO board to the peripheral board according to the table below. Arduino UNO Peripheral board IO_0 (PortD_0) JP3_1 (Diode 1) 3.3V JP7_1(Vcc) GND JP7_5(GND) 2. Connect Arduino to the PC using USB cable Setting-up an Atmel Studio project It is assumed here that Atmel Studio 6.x and Arduino development software are already installed on your PC. 1. Start Atmel Studio and select New -> Project from the menu. 2. Select assembler in New Project window and name your application project. 3. Click OK. 4. Select ATMega328P in the Device Selection window. 6/12

7 5. Click OK The Atmel Studio main window should appear Teach Atmel Studio to configure Arduino UNO Before we write any program, we want to tell Atmel Studio how to configure Arduino UNO board. We will use an external programming tool which is named avrdude, but we will launch this tool from the Atmel Studio Menu. a. Find COM port where your Arduino UNO was installed Ensure that Arduino Uno is connected to the PC and launch Arduino software. Select Tools -> Port from the menu and determine the COM communication port number (It is COM31 in the figure below. 7/12

8 b. Configure External Tool in Atmel Studio 1. In Atmel Studio, select Tools -> External Tools from the menu. The window will appear. 2. Click Add button and fill text-lines Title Arduino Uno programming Command C:\<Arduino software path>\arduino\avrdude.exe Arguments -C"C:\<Arduino software path>/arduino/hardware/tools/avr/etc/avrdude.conf" -v -v -patmega328p -carduino -P\\.\<COMn> -b D -Uflash:w:"$(ProjectDir)Debug\$ (ItemFileName).hex":i Replace <Arduino software path> with a correct Arduino software location in your system and <COMn> with your Arduino UNO port (see 4.3.a). If you have problems, refer to the excellent web reference for an additional help: 3. Click OK in External Window 4.4. Writing the Hello Word morse code application 1. Look at the assembly program that is given below. If you are familiar with AVR architecture and assembly language you will understand what is going on. If not, do not worry. You will learn during Microprocessors laboratory how the program works. 2. Copy and paste the program given below to the code window of tha Atmel Studio GUI 8/12

9 /* * MorseCodeHelloWordApp.asm * * Created: :05:42 * Author: Paweł Russek */.INCLUDE "m328pdef.inc".equ SYS_FREQ = 16 System frequwncyt in MHz.CSEG.ORG 0 jmp reset Reset int handler.org 0x20 Start binaries just after the interrupt table morse_msg: Put 'Hello Word' in morse code as static table in program memory.db '.','.','.','.',' ','.',' ','.'.DB '-','.','.',' ','.','-','.','.'.DB ' ','-','-','-','/','.','-','-'.DB ' ','-','-','-',' ','.','-','.'.DB ' ','-','.','.','/','/','/','/'.EQU MSG_LEN = 40 Define message length.equ DOT_LEN = 5 Define blik length for dot symbols.equ DASH_LEN = 50 Define blik length for dash symbols.equ BREAK_LEN = 20 Define break between symbols.equ SPACE_LEN = 50 Define break for space between words symbol.def.def.def.def.def ZERO = R17 Define register to keep zero value ONE = R18 Define register to keep one value MSG_CNT = R24 Define register to count message characters CHAR = R25 Define register to keep message character DELAY_VAL = R16 Define register for delay value reset: /*Init stack pointer*/ ldi R17, high(ramend) ldi R16, low(ramend) out SPH, R17 out SPL, R16 /*Init registers that hold zero and one values*/ ldi ZERO,0x00 ldi ONE,0x01 /*Init Port D*/ out DDRD, ONE Set PORT D pin 0 as output out PORTD, ZERO main_loop: /*Init Z register as a pointer to the morse message */ ldi ZH, high(morse_msg<<1) ldi ZL, low(morse_msg<<1) /*Init message length counter*/ ldi MSG_CNT, MSG_LEN next_symbol: lpm CHAR, Z Load next message character /*Check if dot*/ CPI CHAR, '.' Compare with dot value brne next_1 If not dot branch out PORTD, ONE Turn on diode for dot ldi DELAY_VAL, DOT_LEN Set delay for dot 9/12

10 call delay_ms rjmp clean_up /*Check if dash*/ next_1: CPI CHAR, '-' Compare with dash value brne next_2 If not dash branch out PORTD, ONE Turn on diode for dash ldi DELAY_VAL, DASH_LEN call delay_ms rjmp clean_up /*Check if space*/ next_2: CPI CHAR, ' ' Compare with space value brne next_3 If not space branch ldi DELAY_VAL, BREAK_LEN Set delay for character break call delay_ms rjmp clean_up next_3: CPI CHAR, '/' Compare with word break value brne clean_up If not break branch ldi DELAY_VAL, SPACE_LEN Set delay for space call delay_ms clean_up: out PORTD, ZERO Turn off diode ldi DELAY_VAL, BREAK_LEN Set delay for break call delay_ms /*Increment message morse message pointer*/ add ZL, ONE adc ZH, ZERO /*Count down characters*/ dec MSG_CNT Decrement message characters counter brne next_symbol If not last character go to next symbol rjmp main_loop If last character repeat main loop /*End of main loop*/ /* Milliseconds delay_ms procedure R16 - delay in tens of ms (for zero us) */ delay_ms: push R24 push R25 push R26 mov R26, R16 ldi R25,10 delay_ms_1: ldi R24,100 delay_ms_2: mov R16, R26 refresh R16 value call delay_us dec R24 brne delay_ms_2 dec R25 brne delay_ms_1 pop R26 pop R25 pop R24 ret 10/12

11 /*End of delay_ms procedure*/ /* Rafał Baranowski delay_us procedure R16 - delay in tens of us (for zero us) */ delay_us: push R17 push R18 mov R18, R16 ldi R17, SYS_FREQ wait_us_0: mov R16, R18 wait_us_1: dec brne R16 wait_us_1 dec brne R17 wait_us_0 \ \ p p 1 0 / / pop R18 pop R17 ret /*End of delay_us procedure*/ 2. Select Built ->Built solution from the menu to compile the code. 3. Check in a console window of Atmel Studio if the compilation went successfully 4. Select Tools -> Arduino Uno Programming to download program to the Arduino board and... 11/12

12 5. Enjoy your application If the LED diode does not blink check, the messages of avrdude in the command console. Below You will find how a correct procedure goes. avrdude: Version 6.0.1, compiled on Apr at 23:12:16 Copyright (c) Brian Dean, Copyright (c) Joerg Wunsch System wide configuration file is "C:/Program Files (x86)/arduino/hardware/tools/avr/etc/avrdude.conf" cygwin warning: MS-DOS style path detected: C:/Program Files (x86)/arduino/hardware/tools/avr/ etc/avrdude.conf Preferred POSIX equivalent is: /Arduino/hardware/tools/avr/etc/avrdude.conf CYGWIN environment variable option "nodosfilewarning" turns off this warning. Consult the user's guide for more details about POSIX paths: Using Port : \\.\COM31 Using Programmer : arduino Overriding Baud Rate : AVR Part : ATmega328P Chip Erase delay : 9000 us PAGEL : PD7 BS2 : PC2 RESET disposition : dedicated RETRY pulse : SCK serial program mode : yes parallel program mode : yes Timeout : 200 StabDelay : 100 CmdexeDelay : 25 SyncLoops : 32 ByteDelay :0 PollIndex :3 PollValue : 0x53 Memory Detail : Block Poll Page Polled Memory Type Mode Delay Size Indx Paged Size Size #Pages MinW MaxW ReadBack eeprom no xff 0xff flash yes xff 0xff lfuse no x00 0x00 hfuse no x00 0x00 efuse no x00 0x00 lock no x00 0x00 calibration no x00 0x00 signature no x00 0x00 Programmer Type : Arduino Description : Arduino Hardware Version: 3 Firmware Version: 4.4 Vtarget : 0.3 V Varef : 0.3 V Oscillator : khz SCK period : 3.3 us avrdude: AVR device initialized and ready to accept instructions Reading ################################################## 100% 0.00s avrdude: Device signature = 0x1e950f avrdude: safemode: lfuse reads as 0 avrdude: safemode: hfuse reads as 0 avrdude: safemode: efuse reads as 0 avrdude: reading input file "C:\Users\Pawel\Documents\Atmel Studio\BlinkingDiode App\BlinkingDiodeApp\Debug\BlinkingDiodeApp.hex" avrdude: writing flash (258 bytes): Writing ################################################## 100% 0.06s avrdude: 258 bytes of flash written avrdude: verifying flash memory against C:\Users\Pawel\Documents\Atmel Studio\Bl inkingdiodeapp\blinkingdiodeapp\debug\blinkingdiodeapp.hex: avrdude: load data flash data from input file C:\Users\Pawel\Documents\Atmel Stu dio\blinkingdiodeapp\blinkingdiodeapp\debug\blinkingdiodeapp.hex: avrdude: input file C:\Users\Pawel\Documents\Atmel Studio\BlinkingDiodeApp\Blink ingdiodeapp\debug\blinkingdiodeapp.hex contains 258 bytes avrdude: reading on-chip flash data: Reading ################################################## 100% 0.05s avrdude: verifying... avrdude: 258 bytes of flash verified avrdude: safemode: lfuse reads as 0 avrdude: safemode: hfuse reads as 0 avrdude: safemode: efuse reads as 0 avrdude: safemode: Fuses OK (H:00, E:00, L:00) avrdude done. Thank you 12/12