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Questions tagged [sd-card]

SD cards are often used with the Arduino Ethernet Shield. They stand for "secure digital cards" and fit into one's palm. They range from 256MB to 128GB, although most Arduinos only use 4GB. There are also SD micro cards, a smaller version of the cards.

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Combining Strings into a datestamp

I'm creating a weather station / environmental datalogger and am saving my data to a SD card Breakout. The SD card works fine but I would like to name the files I am saving on it after the date when the readings were taken.I've tryed multiple things…
SquarePie
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Reading SD card with Sparkfun MP3 Shield

So I am using an Arduino Mega with the Sparkfun MP3 shield. And I can't seem to read the µSD card. It's formatted in FAT32 and it has a single .txt file on it. I always get this error: SD initialization failed. Do not reformat the card! Is the card…
Michidez
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SD card initialization fails randomly

I have a SD card reader that is working fine exept that sometimes SD.begin fails for no apparent reason. To work around this issue I have put the SD.begin in a while loop and then I display the error on my LCD. When the error happens I then remove…
Aoaoaoappa
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How to use a microSD card reader with SCK instead of CLK?

I've bought this microSD reader/writer: http://www.ebay.com/itm/131132034753 I've found only one tutorial, where the pins are similar to my pins, but in the example there is a CLK instead of SCK:…
Iter Ator
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read first line from sd card and save the position for again reading from sd card

I am reading sd card .txt file, I want to read the first line then how to save the position of the pointer for the next line read?
Shrikant Nikam
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Openlog + Lilypad Simple board - not writing to SD card

I'm desperately trying to get my openlog to work and write data out to a micro SD card with no luck. I'm using a battery-powered lilypad arduino simple board and have attached L-shaped female headers to to the openlog to plug it right in. I am also…
claudybee
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Writing on a SdCard

I'm writing on a SD card the value of a measured voltage. I've a good sampling/writing frequency but regularly the acquisition take a lot of time (like 4000us instead of 400us). I noticed that this "pause" appears every 85 values (my values are 6…
bouaaah
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Why is SD card failing to begin?

I recently bought a micro SD storage shield for my arduino project, this is the link. My final goal is to log information every 100 ms about the temperature and pressure of my device using another one of my sensors. However, I started by testing out…
Pablo
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SdFat: Why does the first write to the file take so long?

I have tested this problem on 6 micro-SDHC cards of 3 different types. 3 are 32-GB Sandisk, 2 are 16-GB Kingston, and 1 is 16-GB Samsung. These cards are used in data loggers and typically contain hundreds or thousands of 5-MB text files whose names…
Vulcan
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Adding more storage to microprocessor 3.3v trinket

Project: I'm a software guy trying to learn more about hardware so I've decided to do a project that uses a small micro controller which plays short sound clips over a .5w speaker. The microcontroller I've selected is Adafruits 3v Pro Trinket along…
Joe Jankowiak
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How to pass a filename to a function? What type of variable is the filename?

In the example below, I have two functions that write numbers to two different files on an SD card. I'm using the SdFat library. Is there any way I can combine the two functions into one, so that I can call (for example): writeToFile(int t,…
Jerry
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Write with SD card; flush versus close?

I've got an application that requires moving to specific points on a file on an SD card, reading, modifying and then writing an update. The file is fixed size. The code has no problems moving to the specific offsets required and then reading in…
Bob
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What is the difference between file.print() and file.write()

From here I think I understand the difference between Serial.write and Serial.print, but is it the same when writing to a file in a SD card for example. Does it mean that File.write saves bytes in the file instead of text?
diego-v
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Efficient way to save accelerometer data on sd card

I have analog accelerometer that transfer acceleration on 3 axis with frequency 5 kHz. I want to store that data in SD card for in txt file. My sketch is the following: void loop() { // Get raw accelerometer data for each axis int rawX =…
Kracozebr
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Read the image value pixel by pixel

I need your help in SD card and image. It's been a week since I have involved with this problem, So I wish you can help me. Here is the problem: I saved a photo to the SD card and now I want to read the color information of each pixel and put the…
Saeed Faal
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