Teensy. 2 USB Mass Storage with an SD card. Iterating on my precedent post, the next logical step is to use the USB interface to access the SD card connected to the Teensy. ATMEGA3. 2U4 with a Mass Storage profile. LUFA Mass Storage demo. The LUFA library offers a mass storage demo. Find great deals on eBay for micro sd card and micro sd card 32gb. Shop with confidence. It is based on the AT9. USBKEY demonstration board that provides two onchip serial flash memories accessed via the SPI bus. With the LUFA demo, the flash memories can ve viewed as an USB flash drive from a host PC. To readwrite data in the flash storage, the host uses the SCSI Primary Command SPC Set and SCSI Block Command SBC Set. Those SCSI commands are wrapped in Command Block Wrapper CBW and Command Status Wrapper CSW structures. Here is a bloc diagram of the demo code The CBW are received from the host and decoded in Mass. Storage. c. The extracted SCSI commands are handled by SCSI. Then Data. Flash. Manager. c provides an interface to readwrite data blocks using the Data. Flash driver. In the SCSICommandReadCapacity1. VIRTUALMEMORYBLOCKSIZE is set to 5. The flash capacity is returned as a number of 5. This is the same block size used in SD card with capacity smaller than 2. GB. The Data. Flash. Manager directly reads small data blocks from the OUT endpoint and write them to the data flash. Doing like that you dont need to store full data blocks in the MCU RAM. Incoming data are only stored in the endpoint buffer before being written to the data flash. The same principle is used to read data blocks from the data flash to the IN endpoint. Integration of a SD driver. The official PlayStationStore Buy the latest PlayStation games, movies and TV shows for your PS4, PS3 and PS Vita. SD Card in SPI Mode My adventure with SD Cards via SPI Youd think that this was an easy task given the amount of documentation that is available. This arduino audiomusic player can amplify and play music from SD card with adding sound effects using your Arduino Board. To play mp3 files using arduino, you need. To access a SD card instead of a dataflash, I simply need a driver able to readwrite raw blocks through the SPI bus. I will re use the sdraw driver from the sd reader library introduced in the previous post. Phone-and-SIM-Info-1.jpg?x56326' alt='How To Get Sd Card Serial Number' title='How To Get Sd Card Serial Number' />Between the SCSI decoder and the sdraw driver, I developped a Sd. Card. Manager adapted from the Data. Flash. Manager of the original LUFA demo. Here is the bloc diagram with my modifications The SDCard. Manager layer implements readwrite operations directly fromto the USB endpoints. The i9 series of SDmicroSD copiers designed for volume SDmicroSD flash memory card programming. Copying at speeds of 1. GB per minute per port. Because data blocks are not stored in RAM, I can not directly use the functions sdrawread and sdrawwrite. Instead I will use the functions sdrawreadinterval and sdrawwriteinterval that allows to do data transfers using callbacks. The hardware. The hardware used to test my application is a Teensy. ATMEGA3. 2U4 with a SD card adapter connected on the SPI bus. The serial port is used to output debug traces. Compiling the project. See at the end of the post how to download my source code. The application code is located in the Low. Level. Mass. StorageSD directory. Just type make to compile it. The resulting Mass. Storage. hex binary can be downloaded to a Teensy. Teensy loader. Connecting to the host. I insert a 2. GB SD in my adapter and connect the Teensy. OS X. Using the serial port and printf, I can see read and write commands being issued to the application. MMCSD initialization failed. USBDeviceSet. Configuration. Programs Help Mortgage Debt Forgiveness here. When the activity stops, I can see my SD card successfully mounted in the Finder I can copy files on the SD card and then read them again without problem. It is just that the transfer speed is suddenly very slow compared to a real SD card reader. Source code. As an experiment, the source code for this project can be downloaded from my Bit. Bucket Mercurial repository http bitbucket. V2. A binary is also available. The repository root address is http bitbucket.