MICROCONTROLLER CIRCUIT WITH PHERIPHERALS Pins NOTE For more details of ATMEGA16, please refer datasheet. GSM MODULE For sending message, I am using a GSM Module. Curiosity Development Board. Your next embedded design idea has a new home. Curiosity is a costeffective, fullyintegrated 8bit development platform targeted at. SDSDHC Card Interfacing with ATmega. FAT3. 2 implementation. Here is my project on interfacing of SD Card micro. SD. micro. SD cards are available very cheap nowadays, a great option for having a huge memory in any embedded system project. It is compatible with SPI bus, so the interfacing is easy. SD card adapters are also easily available in market, one can easily make a bread board adapter by soldering few pins on it. Following figures show the SD card pin out the bread board adapter design by soldering 7 pins of a breakout header on the micro. SD adapter Click on images for larger view. Serial Communication Program For Atmega16' title='Serial Communication Program For Atmega16' />I had started this project with 1. GB micro. SD card from San. Disk later on tested with transcend cards also. The microcontroller is AVR ATmega. ATmega. 32 running at 8. Mhz internal clock. MAX2. 32 is used to interface the circuit with PC for monitoring the data. A 3. 3v supply is used for powering the mega. SD and max. 23. 2 though the specified supply for max. SwHG8zSM/Uet1hwHfBVI/AAAAAAAAAcc/5C7x_8dubnI/s1600/Untitled1.jpg' alt='Serial Communication Program For Atmega16' title='Serial Communication Program For Atmega16' />SD are used here, shown in the figure of pin out. Schematic for ATmega. May 2. 01. 0, SD series resistors are removed, as they were limiting the speed of SPI bus. CMDDAT lines. This gives better stability with different cards. Also, two 3. 6v zeners are added to protect SD in case when the ISP programmer voltage levels are of 5v. Note VCC GND pins of MAX2. Following is the schematic for ATmega. RTC updated on 1. May 2. 01. 0 Following is the schematic for ATmega. RTC added on 1. 7 May 2. CS pin correction, PB4 instead of PB1, done in Mar 2. Here two supply voltages are used, 3. SD 5v for remaining ICs. The aim of this project was to learn interfacing of SD card and to understand the data transfer in raw format as well as in FAT3. I started with raw data transfer, sending some data to any block of the micro. SD, reading a block of it, reading and writing multiple blocks, erasing multiple blocks. All this in raw format. I used RS2. 32 for viewing the data read by microcontroller from SD card. The uc sends the data to Hyper. Terminal. Similarly, to write data to card, the data was fed thru Hyper. Terminal, by typing some text. Once raw data transfer achieved, I formatted the card with windows. XP FAT3. 2 and loaded it with some text files, directories and other files all stored in root directory of the card. After that I wrote the FAT3. Hyper. Terminal again, finding the totalfree memory of card. All this data is sent to Hyper. Terminal by the uc. Serial Communication Program For Atmega16' title='Serial Communication Program For Atmega16' />Following is the Hyper. Terminal window showing different options Options 0 to 4 are low level functions dealing with raw data. If you use option 0, 1 or 3, you may have to reformat the card before using the FAT3. Erases selected number of blocks strating from selected block. Writes data to specified SD block address. Data to be entered in Hyper. Terminal using PC keyboard. Readss data of specified SD block address. Data is displayed on Hyper. Terminal window. 3. Writes selected number of blocks strating from selected block. Reads selected number of blocks strating from selected block. Here, the multiple block functions related to options 3 4 are disabled due to memory constraint as that time mega. FAT3. 2 testing. While testing with mega. FATTESTINGONLY defined in SDroutines. Options 5 to 9 are related to FAT3. Only short file names are supported right now, 8byte name3bytes extension. If you store a long name file in SD, it will be displayed by these routines in short name format only. For testing these options, format the card with FAT3. Hyper. Terminal. Displays list of available directories and files with size in the root directory of the card6 Reads a specified file and displays the file contents on Hyper. Terminal. 7 CreateAppend file with specified name, enter text from Hyper. Terminal. 8 Deletes any existing file with specified name. Displays total free memory of the card using FSinfo sector of the SD cardFollowing figures show the Hyper. Terminal window when options 5 9 are selected These figures show menu from Ver. Menu style is changed from Ver2. Note Hyper. Terminal is used here at 1. Human Biology Mader 12Th Edition Pdf. No parity, Flow Control none. This project needs very few components and can be done easily at home. Try it out Download the source code files from here Download here the zipped source code files modified for mega. AVR AVRStudio. Version 2. RTC added for DateTime entries1. May 2. 01. 02. 4 Apr 2. Version 2. 3 SDHC support added 0. May 2. 01. 0Version 2. No SDHC support1. Sep 2. 00. 9Download EAGLE schematic file of Ver 2. Downloadview source code files V2. ATmega. 8 Following files are compiled using win. AVR inside AVRStudio. This Version does not support SDHC cards. Also, append file feature is not available. SDmain. c. 2. SDroutines. SDroutines. h. 3. FAT3. 2. c FAT3. Ver 2. Sep 0. 94. SPIroutines. SPIroutines. h. 5. UARTroutines. c UARTroutines. Makefile. 7. HEX fileVer 2. Sep 0. 9Please put up a comment or mail me if you find a bug in the code. The updates are because of valuable suggestions comments from the users of this code. Thanks a lot Buy from Farnell Element. ATmega. 32 India, ATmega. USARelated posts You can visit my post of micro. SD ATmega. 32 Data Logger, which uses modified FAT3. If you want to test FAT3. SD FAT3. 2 using Visual CUpdate History Version 2. Real Time Clock circuit support is added for time date entries in the files. Now the current date of file creation and file update will be entered in the FAT table can be viewed by checking file properties using a PCThe RTC will also be useful in data logging with time stamp Three more options added in the Hyper Terminal menu for displaying or updating RTC date time. New menu is shown in the above figure. Ver 2. 4. 1 Same as 2. RTC twiinit function added to define I2. C clock freq. 1. 00. K 1. 6MHz 5. 0k8. MHz. This was taking default values earlier, which was as high as 5. K8. MHz, not desirableNote Version 2. ATmega. 32, but they can be adopted to any controller having RAM 1. KB and Flash 1. KBCurrent memory usage Ver2. Flash 1. 29. 08 Bytes RAM 7. Bytes appx. Version 2. Support for SDHC cards added tested with San. Disk Transcend micro. SD and micro. SDHC cards. The initialization sequence and command formats are modified. A bug which was causing the program flow to go into infinite loop if the character number 5. CR Carriage Return, r, in the write. File function. Thanks to David Piotr M. Code is also tested successfully at 1. MHz clock 8. MHz SPI clock with for SDSDHC cards. Follwing are the Hyper Terminal windows showing card detection One window shows baudrate as 3. MHz internal clock of Mega. Version 2. 2 Append file feature added. File function replaced with write. File, which looks for the filename first, if the given file name doesnt exist then it creates new file and writes data, but if the file already exists, then it opens it and appends the entered data. A bug removed which was giving error related to use of LONG The FAT3. Sep 0. 9to remove a bug which was limiting file size to 3. MB Thanks to Kun Szabo Marton who pointed it outData transfer rate 1 raw data block 5. KBytess at current 4 MHz SPI clock rate. If you have flash more than 8k, you can declare the SPIreceive and SPItransmit functions as inline functions. This will increase the transfer rate to 1.