The AK-SDFS-UART board allows you to read/write data from/to a micro SD card using a serial TTL port (UART). The board supports the FAT file system so the files can be read back from the micro SD on a PC/MAC.

Using a simple protocol (libraries included) you can read/write 4 files concurrently, in text or binary mode. Using only four wires (TX, RX, VCC and GND) you can read and write from the SD using very small microprocessors, even 8-bit ones. The baudrate can be adjusted from 9600 up to 460800 bps.

We have prepared a library that encapsulates the communication protocol and the source code can be downloaded. There is also an Arduino sketch demonstration available for download.

The AK-SDFS-UART is perfect to be used as a data logger, for sensors and debug information. It supports micro SD and SDHC cards.

We also have a standard SD version of this board.

Features

  • Only four wires to get a working FAT File System
  • Powered from 3.3V external supply
  • All I/O pins are 5V tolerant
  • Operates on 4 files concurrently
  • RTC supported (time and date command has to be given at every power up)
  • Supports all file commands as Open, Create, Exist, Close, Write, Flush, Read, Size
  • Supports long file names
  • Supports directory tree listing
  • Commands to create and delete directories
  • Supports binary files
  • Uses a single and secure UART protocol. Source code examples are provided
  • Breadboard-ready
  • Supports firmware upgrade

Documents

Software

Additional information

Weight 0.070 kg
Dimensions 20 × 22 × 20 mm

Comments


Avatar
Member
Wolfzi99
1 year 8 months ago

Hello
I bought this module and it doesn’t work!!!
1. I use an Atmega1284 (UART0, 9600 Baud) to control the module
2. When I insert an SD card, the DISK LED does not light up
3. I don’t get feedback from the module when I send a command.
4. I use CRC16-CCITT as a checksum, okay?
Can the module be defective?
Or what am I doing wrong?

Regards
Wolfgang

Ivan
Support
1 year 8 months ago

Hi,
Ok, let’s figure this out. But first I wanted to ask if you can use the forum (https://forum.artekit.eu/) for this kind of support, since the comment section for the product is not the appropriate place.

Remember to post as much information as possible: a simple code example of what you are doing and seeing problems, a schematic of your connections, also a picture if possible, etc.

Avatar
Member
Wolfzi99
1 year 8 months ago

Hi Ivan,
okay, will do!

Regards
Wolfgang

Avatar
Member
Wolfzi99
1 year 8 months ago

Hi,
what means CRC16 exactly?
Which data should I take to calculate?
Regards
Wolfgang

Ivan
Support
1 year 8 months ago

Hi,
The CRC16 is calculated from all the fields (Preamble, Command, File handle / opt, Data length and Data) using the function described in the documentation (link is here above as “User manual).

Avatar
Member
Wolfzi99
1 year 8 months ago

Hi Ivan,
thank you for your answer. I think that will helps me!
Regards
Wolfgang

Avatar
Guest
Tasos
3 years 7 months ago

Hello, are there any libraries/guide in C for interfacing the SD card Shield with ATMEGA16L MCU?
Thank you

Ivan
Support
3 years 7 months ago

There is the protocol library, written in C, that is generic (the link is up here in the description). Since it’s microcontroller-agnostic, you have to provide 3 functions: one for serial data transmission, one for serial data reception and one implementing a delay.

Avatar
Guest
Andy
5 years 4 months ago

I have the product. Ready to test. It seems a shame that there is no 5V input option, since the I/O are 5V tolerant and there are several unused header pins, surely a 3.3V LDO regulator would be a good idea to allow the option of powering from 5V since many serial ports have 5V on one of the pins

Ivan
Support
5 years 4 months ago

Hi Andy. Thank you, we will consider introducing a regulator in future models.

Avatar
Guest
Andy
5 years 4 months ago

This looks great and I have ordered one. Do you have information on sustaoned write rate or how fast I can write to disk. So say I had a single file open, how long would it take to write for exampe 1,000,000 bytes, assuming continous transmission ( say by DMA) on the client side.

Ivan
Support
5 years 4 months ago

Hi Andy. With a 460800bps UART, you can write more or less 16KBytes/s.

Avatar
Guest
Andy
5 years 4 months ago

Hi Ivan,
Testing on PC at 460800 baud, I seem to be getting a write speed of 28,00 bytes per second. I guess its dependent on SD-card. I am using class 10 SD-card, but they say there is a fair bit of variation. Anyway it is a nice product :). I wonder if it would be possible to up baudrate to 1000000 or 1,500,000 or even to 4608000? I am sure STM32F1 is capable. Also the docs dont mention any higher baud than 115200..

Avatar
Guest
Andy
5 years 4 months ago

sorry above should be 28,000 bytes per second

Ivan
Support
5 years 4 months ago

Nice. Yes, we got 16KB/s with a class 4 microSD.
Thanks for the tip about the documentation. We’ll update it with the right baudrate values.

 

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AK-SDFS-UART - SD File System Through UART

The AK-SDFS-UART allows you to write and read files from a standard microSD with FAT file system using an UART.

24.90

In stock

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