MICROCONTROLLER ETHERNET INTERFACING

Transcription

1 MAE 285 Laboratory #5 Purpose MICROCONTROLLER ETHERNET INTERFACING To introduce to Ethernet protocol standards To develop familiarity with how to connect devices using the Ethernet port To reinforce C program standards and coding documentation To explore the similarities and differences between Ethernet protocol standards Learning Objectives: Upon successful completion of this laboratory experiment, the student will be able to: 1. Identify what a RJ45 is and what it has to do with Ethernet communication. 2. Explain what logic voltage levels are used for Ehernet communication. 3. Describe where to find specifications for the Ethernet communication protocol. a. Explain the meaning of layers as it pertains to the Ethernet standard. b. Describe the difference between these layers and their perspective function. 4. Describe the differences between a 10T and a 100T Ethernet system. 5. Apply knowledge from reading assignment and reset the password on the Ethernet board. 6. Apply knowledge from reading assignment and attaché the Atmel JTAG IC to the CPLD and download code. 7. Verify, with the port Sniffer that the data being transmitted from the microcontrollers match the data being received by the web page. 8. Determine what percentage of the information from the microcontroller does the web browser not use. 9. Classify the differences between hardware and software implementation of Ethernet protocol incorporating a microcontroller, and the advantages and disadvantages of each. Lab Preparation The following pre-lab preparation is required to be able to successfully complete this lab. Completion of Introduction to the Atmel Atmega 128 controller. (see course website) Completion of Quick Start Guide for the Embedded Internet Toolkit. (AVR461) The following optional reading will help in deeper understanding of the experiments. Read data sheet for Atmel s ATMEGA 128 section XXX and XXX covering the setting of processor clock speed and calculating scaling bit for serial baud rates. (Atmel) Read data sheet for Crystal CS8900A-C0 chip section XXX and XXX covering the operation of the chip. Components Qty. Items 1 AVR Embedded Internet Toolkit with a Atmega 128 processor 1 STK500 2 Serial LCD

2 1 Serial Adapter board 1 JTAG ICE 1 or mkii 1 Serial port cable Male to Male (straight thru) 1 Bread board 1 Opto-isolater 1 Ethernet cable, twisted (Orange) 1 Ethernet cable, straight thru (Yellow) Lab Overview The Ethernet Lab requires you to utilize the following programs on the PC: Hyper Terminal, AVR studio, Internet Explorer, a Text editor, EtherReal and a C compiler to generate code for an Atmel chip. Hyper Terminal is a free software terminal emulator (communication program) for MS-Windows. It supports VT100 emulation, telnet connection, serial port connection, and so on. AVR Studio 4 is the new professional Integrated Development Environment (IDE) for writing and debugging AVR applications in Windows 9x/NT/2000/XP environments. AVR Studio 4 includes an assembler and a simulator. The AVR Studio supports the following AVR development tools are also supported: ICE50, ICE40, JTAGICE mkii, JTAGICE, ICE200, STK500/501/502 and AVRISP. Internet Explorer or equivalent web page browser used to interrupt information sent from a web site and prepare it for display on the local host computer. Different web browser interprets the information set to them differently and the pages on the Atmel have been only verified with I.E. Text editors like Note pad or Ultra Edit, Microsoft word can be used buy it has to be save without the additional hidden characters the word adds to a text document. The text editor will be used to create your web pages and update them as needed. Port Sniffer is a program the listen to the Ethernet port on the computer and saves all information from it into a log. This program is useful for debugging and verify what is going out and coming into your Ethernet port. A C compiler, like ICCAVR or GCC, to create and update code used for this project and stored on the microcontrollers. Both of these compilers are free to download from the web. The ICCAVR has a limited time full feature use then it implements a 4K limit on program size. GCC on the other hand has no time limit. The software for this lab has been developed or verified operational with ICCAVR. Ether Real is a program the listen to the Ethernet port on the computer and saves all information from it into a log. This program is useful for debugging and verify what is going out and coming into your Ethernet port. This lab requires you to connect the Embedded Internet board to the computer using the Ethernet port on the board and your computer as well as one serial port from the STK500 to the computer and the second serial port on the computer to the embedded web server serial port. You will need to have the port Ethereal software load on your computer and operating before you open the web browser to view the home page on the Embedded Internet Toolkit. The first step in using this board will require you to connect to primary serial port of the board to the serial port of the computer. This step may require you to use a USB to serial adapter cable. Once you have this hooked up and the serial communication rates refer to serial lab and Ethernet board documentation on setting, power up the board. You will be uploading and down loading web content by using a DOS window and the FTP function.

3 COMPUTER RUNNING PROGRAMS RS232 Connection ETHERNET Connection Atmel s Ethernet Board RS232 Connection Port2 STK500 ISP 6 pin Ribbon Fig.1 Laboratory setup for Ethernet communication lab This figure depicts the configuration of the Ethernet and serial cables between the compute running Hyper Terminal and Internet Explorer and Ethernet board mounted with an ATMEGA 128 processor. Introduction In this lab you will investigate how to program a microcontrollers by use of a serial interface as well as ISP functionality built into the STK500. There will also be work on using FTP functionality to upload and down load web content. There will also be monitoring of the web port by software Ethereal to see what is being sent and received over the port. You will also be investigating key operation of uploading a program and by using AVR studio s emulator mode to step through code to verify and validate functionality. Key Questions As you begin this lab, please review the following questions that you will be required to answer as part of your lab report. Think about the questions as you perform each lab, note there is no one correct answer for these questions so provide your reasoning and justifications for each answer. 1) What effect, if any, would a change from a crossover cable to a straight through cable have? 2) Explain how you would integrate a larger memory chip into the Ethernet board and describe how you would code and complete the circuit using your chosen components. 3) Should there be current (e.g., maximum amperage) specifications associated with these protocols? 4) Identify as many things about the circuitry that will limit the maximum rate at which data can be reliably transmitted, and explain why. (e.g., what effect might the length of the wires have? 5) Is it possible that the power supply could have an effect, and if so, what? 6) Explain why you may use 10 base T, over 100 base T. Procedure 1. Remove the STK501 board from the STK500. Slowly rock the board out of the connectors to prevent bending the pins. 2. Make sure the 6 pin ribbon cable is connected to the ISP header on the STK500 board.

4 3. Connect 12 VDC Power to the STK500. Verify 12 volts before plugging power into the STK Connect 12 VDC Power to the AVR Embedded Server board. Verify 12 volts before plugging power into the board. 5. Connect a serial cable from the communication port 1 of the computer to the RS232 CTRL port on the STK500 main board. This will be used to download and debug code for this experiment. 6. Connect a second serial cable from the computers communication port 2 to the AVR Embedded Server board. 7. Connect a cross over CAT5 or CAT6 cable from the PC RJ45 to the RJ45 on the AVR Embedded Server board. 8. Connect the 6-pin ribbon cable from the STK500 to the ISP 6-pin header on the AVR Embedded Server board. Verify that the red wire goes from pins 1-2 on the STK500 to pins 1-2 on the AVR Embedded Server board. 9. If instructed by TA, you may need to compile all three programs used in this lab. If so you will need to open the folders and file specified by the TA. Compile the code using ICCAVR, as the code has not been checked for compiling using GCC. The TA will provide compiler configuration setting. 10. Open AVR studio 4. Make sure the power is ON on the STK500 board and the AVR Embedded Server board. 11. Click the small icon in the AVR studio window that looks like a small IC with the letters AVR on it. A new window should pop up, if not see the TA. 12. Verify that the new window has the title STK500 module. If not, see TA. 13. Click on Program TAB and set device to ATmega 128. This is a pull down device menu. Find the ATmega 28 in this list. The program mode is ISP. Verify that both are correct. 14. Click the board tab and verify the voltage on the board by clicking on read voltage button. Did you get the voltage reading back? If not, see TA. 15. Now click on the Read button under Oscillator and ISP clock. The two numbers should be STK500 = Mhz and ISP Freq. = Khz. If not, set these two numbers using the pull down menu and then press the write button. Then press read again to verify that the write took place and that the numbers are correct. If any problems with this, see TA. 16. Click on the advance tab and press read button. You should get a number like Ox?? Ox?? Ox?? Where the?? are HEX values between 0 and F. If you don t see this, contact the TA. 17. Below the Ox?? Ox?? Ox?? There will be a message. Verify that it states that this number matches the device selected. If it states that the device does not match, return to step 12 and start over. If you are still having problems, see the TA. 18. Click on the Lock bit tab and check that it is set correctly. The following bits should be checked; Mode 1, Application Protection Mode 1 and Boot Loader Bit. If any are not checked, ask the TA for help. IF THESE ARE SET WRONG THE CHIP CAN T BE USED AGAIN, LAB OVER. 19. Click on the fuse bit tab and verify the following items are checked; ATmega 103 compatibility mode, JTAG enabled, boot flash section size = , Brown out detection level at VCC = 2.7 B, and Ext. Crystal/resonator High Frequency start=up time 16 K ck + 4 ms If these are not configured this way, see TA. 20. Click PROGRAM tab and then the Read Button in the FLASH section of the program window. A SAVE AS pop-up window will appear. Name the file whatever up want. Before saving the file create a new folder under ME285 folder on the desktop. Now click SAVE and you will see four OK! In the dialog window. If you did not see this, see the TA

5 21. Close the STK500 dialog window. 22. Open ultra Edit or some other text editor program. Open the file you just uploaded and saved from the AVR Embedded Server board. The file will have your file name with the extension HEX. 23. The file is in HEX with is what is downloaded to the ATmega128. The HEX is compact version of the Binary, which is what the processor really operates on. If you scan the file to the bottom of the file you will come to a section that is full of F s. This is the section of memory that had no program loaded in it. You can see that a large portion of the 12K of memory is without any program. 24. Now open AVR studio if it is not still open. Open the file you just had open in the text editor. File-open file, a new popup window will appear, select AVR simulator and ATmega128 processor the select finish. 25. The File you see is in the disassembler window in the AVR studio. This file shows the assembly code of the program. This is the next higher level of code writing and just below C code. If you want to you can run through the code in the simulator and view IO registers and other memory location as the code executes. 26. Congratulations you have finished the first part of the lab. 27. Now we are going to look at the web page on the AVR Embedded Server board and create our own web page. 28. To set up your PC to connect directly to the Embedded Internet Toolkit, an IP address in the same range as the Toolkit s must be assigned to the PC. In Windows environments, this should be done as follows (some Windows versions might deviate slightly in appearance): Connect the PC and the AVR Embedded Server board with the crossover Ethernet cable. Open the Windows Control Panel. Select Network. Select TCP/IP -> the PC s Ethernet adapter from the Configuration tab as shown in Fig. 2. Fig. 2. TCP/IP Configuration Push the Properties button. A TCP/IP Properties box similar to Fig. 3 should appear.

6 Fig. 3. TCP/IP Properties Select the IP Address tab. Choose to Specify an IP address as shown in Fig. 3. Insert the IP address and the corresponding subnet mask as shown in Figure 2. Save your settings by pressing OK in both TCP/IP properties and Network properties. Reboot your PC. 29. To start the terminal software, open the start menu, select Programs, ATMEL AVR Tools and AVR Web Server Terminal to start the software. To load the default setting, open the File menu and select Load. Fig. 4 shows the settings in the web server terminal. Fig. 4. Web Server Terminal Window 30. The follow explains each setting used in the Web Server Terminal Window:

7 Web Server Setup DHCP Enable If DHCP (Dynamic Host Configuration Protocol) is enabled, the web server will automatically initialize the IP address from a DHCP host. Use of DHCP requires a DHCP host to be set up on the network. DHCP enable disables manual IP address setup. IP Address Sets up the IP (Internet Protocol) address of the web server. Make sure the IP address is available on the local network. For complete description of IP addresses, see the AVR Web Server documentation. MAC Address Configures the MAC (Media Access Control) address of the web server. The MAC address must be a 48-bit hex value. For complete description of MAC address, see the AVR Web Server documentation Setup The AVR Embedded Web Server can be configured to send s to an address specified in the web server terminal. The sender and receiver address can be written directly into the setup section. The Host name is used to identify the web server to the mail server. The server IP address specifies the address of the server. FTP Setup The FTP setup section specifies the user name and password to log on to the AVR Embedded Web Server using FTP (File Transfer Protocol). The default is ews, but this can be reprogrammed to any desired setting. Please leave these at the default setting. Write The software writes the configuration settings to a local file called server.ini. When the write button is pressed the local file is transferred via the RS-232 serial interface to the Internet Toolkit. Make sure that an RS-232 cable is connected between the PC and the Internet Toolkit and that the Toolkit s network connection is running correctly before pressing the write button. NOTE: The file is transferred to the Internet Toolkit using the ymodem protocol. The default settings are 9600 baud, no parity, 8 data bits, and 1 stop bit (9600, n, 8, 1). In the setting menu, the UART settings can be changed from their default values in the Settings menu. The new settings become operative the next time the EIT is reset or powered up. 31. Click on the settings tab and then click on RS232. Verify the RS232 settings that you are connected to the correct port to communicated to the AVR Embedded Server board. NOTE: The file is transferred to the Internet Toolkit using the ymodem protocol. The default settings are 9600 baud, no parity, 8 data bits, and 1 stop bit (9600, n, 8, 1). In the setting menu, the UART settings can be changed from their default values in the Settings menu. The new settings become operative the next time the EIT is reset or powered up. 32. After verifying the setting click on WRITE button 33. The following dialog box should appear. 34. Once the download is successful, power cycle the AVR Embedded Server board 35. Now to check that the AVR Embedded Server board can be reached. Click on the tool tab which will open a PING test window. If the PING was not successful, please see TA for help.

8 36. Now open Internet Explorer or other web browser. Type in the web address of the web page, in our case it should be Then press enter, the web page should now load. If not, please see TA for help. 37. Congratulations, you now have a web server. With a change to the IP address and connecting it directly to the Internet you could have you own web site. You are complete with section two of the lab. 38. For section three you are going to create a new web page for Dr.Du on you web site. Note; The Embedded Internet Toolkit includes 256 Kbytes of Flash memory that can be accessed remotely from the network with FTP (File Transfer Protocol) or via RS-232 and ymodem protocol from a terminal program (For instance Hyperterm). The files can be of any type, web pages, pictures, applications or JAVA applets being the most common ones. 39. You will be using the DOS prompt widow to communicate to the AVR Embedded Server board. To open a DOS window click the start menu, program, Accessories and MS-Prompt. 40. The first thing to do is to recheck the communication to the AVR Embedded Server board by typing PING (space) in the DOS prompt window. 41. Verify that you have a good connection by having a successful ping response. If your ping times out, see TA for help. 42. We are now ready to view the web page directory. Type FTP (space) and the web address of the server You will be prompted for the user name EWS and the password EWS. See fig. 5 as to what the DOS window should look like. Fig. 5. Using FTP from a DOS Window 44. You are now logged into the web site s file system. 45. Type in dir and the director will be displayed in the window. 46. You should see something like what is shown in Fig. 6.

9 Fig. 6. Listing of Files in the File System 47. Type ls in the terminal window and see the list of files on the server. We are now going to upload a few.htm files from the server. To do this you need to type GET in the dos window as follows. To transfer files from the Toolkit to the PC type get name.ext where name.ext is the name of the file. Files in the file system can t be overwritten, and must therefore be deleted before re-written. To delete a file, type rm name.ext. To change the directory from which you want to transfer the files from your PC, type LS directory where directory is the target path on your PC. For more information, type? in the dos window for help. NOTE; make sure you have the files uploaded to the PC before you delete any file on the server. 48. Open the index.htm file in Ultra edit or other text editor program. 49. Open the INDEX.HTM file in Ultra edit or some other text editor program. 50. Find the following section of code: <tr> <td ALIGN=CENTER WIDTH="100" class="topmenuselected"><a href="index.htm" class="topmenuselected">main</a></td> <td ALIGN=CENTER WIDTH="100" class="topmenu"><font color="#ffff00"><a href="io.htm" class="topmenu">controlling I/O Example</a></font></td> <td ALIGN=CENTER WIDTH="100" class="topmenu"><font color="#ffff00"><a href="ac.htm" class="topmenu">air Condition Example</a></font></td> <td ALIGN=CENTER WIDTH="100"><font color="#ffff00"><a href="name.htm">display

10 name Example</a></font></td> </tr> This is the section of HTM that calls out how the web page menu is to be displayed. 51. We are now going to add a new web page for Dr.Du to the menu. Look at the bold section to see what to add: <tr> <td ALIGN=CENTER WIDTH="100" class="topmenuselected"><a href="index.htm" class="topmenuselected">main</a></td> <td ALIGN=CENTER WIDTH="100" class="topmenu"><font color="#ffff00"><a href="io.htm" class="topmenu">controlling I/O Example</a></font></td> <td ALIGN=CENTER WIDTH="100" class="topmenu"><font color="#ffff00"><a href="ac.htm" class="topmenu">air Condition Example</a></font></td> <td ALIGN=CENTER WIDTH="100"><font color="#ffff00"><a href="name.htm">display name Example</a></font></td> <td ALIGN=CENTER WIDTH="100"><font color="#ffff00"><a href="drdu.htm">dr.du web page</a></font></td> </tr> Now that we have the index.htm file changed, we need to create the Dr. Du homepage. To do this, find the file drdu.htm in the ME285 folder on the computer desktop. 53. Open this file in Ultra edit or some other text editor and also in fire fox or some other web browser. Modify the page as you see fit to help Dr.Du's students. 54. For the Dr. Du web page you are going to have to modify the link to Dr.Du's image. 55. Find the section of code that links to Dr.Du gif file and rename the link to drdu.gif. 56. Open the DOC prompt window and log into the AVR embedded web server using FTP. 57. The ftp terminal connection will time out if you are not actively using it. 58. In the termial window type put C:\ (path to the drdu.htm file). For this example the file is located in the C:\ dierctory ftp> put c:\wdu.html

11 200 PORT command successful. 150 ASCII data connection. 226 Transfer complete. ftp: bytes sent in 0.00Seconds Kbytes/sec. Ftp> If you do not get this, ask for help from the TA. 60. Next, download the drdu.gif file to the AVR embedded web server. Follow the steps you used in the previous download. 61. Now you need to download the index.htm page. The first thing to do is to verify that a copy of the index.htm is stored in a backup folder on on the PC. Once this is verified, you will need to delete the index file on the AVR embedded web server board before downloading the new index.htm file. 62. To do this you will be working in the DOS prompt window. Type delete index.htm and press enter. The DOS window will send a message when this is completed. If you get an error, ask the TA for help 63. Now you need to download the index.htm page to the AVR embedded web server board by using the put (path to file)(file name and extension) in the dos prompt window. Wait for the download to complete. You should get a message about the downloading being complete. If this does not happen ask the TA for help. 64. Reset the AVR embedded web server board. Open up fire fox or some other web browser and log into the AVR embedded web server board using the board s IP address. 65. Reloading the page may be necessary to get the new page to display. If you don't see the Dr.Du home page link in the menu area, review all the previous steps. If there is still a problem, see the TA. 66. With the page loaded, click on the Dr.Du home page. Verify that it loads and displays all the information correctly. The off AVR embedded web server board links will not work right now but will when and if the AVR embedded web server board is connected directly to the Internet. 67. Go back to the main page and try out some of the other web pages. Turn the AVR embedded web server board's LED on and off. Open the code up and review how this works. 68. Congratulations, you have completed the basic lab. References Furman et. al., Intro to the Atmega 128 Microcontroller Eady Fred; Networking and Internetworking with Microcontrollers Paperback, ISBN: , 480 pages, publication date: 2004 Imprint: NEWNES Atmel; ATMEGA bit AVR microcontroller with 128K Bytes In-System programmable Flash Datasheet, Microchip; PIC12F629/675 Data Sheet, 8-Pin FLASH-Based 8-Bit CMOS Microcontrollers AVR461: Quick Start Guide for the Embedded Internet Toolkit