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Topic: SD card error - SOLVED (Read 3 times) previous topic - next topic

wlewis

#5
Jul 19, 2011, 11:47 am Last Edit: Jul 20, 2011, 12:46 am by wlewis Reason: 1
1. if your sd card is not spi compatible.. you simply will not get any results - if (as a last resort) you use your cel phone's sd card (assuming its recent) make sure you get your cel phone's permission.. mine was in the cel phone switch off menu.

2. The 74HCT244N also works.


Boffin1

Hi Rob,

Did you come right with your SD cards?  I have had problems using any card other than the old  256 Mb ones, but all the latest ones like the 2 Gb and micro SD with adaptor fail after a while. ( weeks or a month )

I changed the 125 chip and it made no difference.

I have resorted to buying old smaller cards from camera repair shops !
With my mobile phone I can call people and talk to them -  how smart can you get ?

CrossRoads

Hi John,
Yes, I only tested with a 16 GB Sandisk Ultra 15 MB/s SD card, and a Pony something or other 4GB microSD card in a SD adapter.
Both tested fine with fat16lib's SdFat library and the 74AC125 chip.

I believe the key is having enough current at 3.3V. I used a seperate regulator good for 400mA that only drives the SD circuit.
Designing & building electrical circuits for over 25 years. Check out the ATMega1284P based Bobuino and other '328P & '1284P creations & offerings at  www.crossroadsfencing.com/BobuinoRev17.
Arduino for Teens available at Amazon.com.

Boffin1

You might be right there Rob,
If you have got the microSD in the adaptor working reliably, you are miles ahead.

I will try a separate 3.3v supply when I have one hooked up on the bench again ( and scope the supply as it is first )
With my mobile phone I can call people and talk to them -  how smart can you get ?

CrossRoads

Electrically it went very smooth.  Basically using the same interface as the the adafruit shield.

Software was trickier - I had to figure out how pins_arduino.c mapped the physical pins to the names they respond to, how to make my usage of the ATMega1284 get called out in place of the generic callout (which pretty much says if its not a 1280/2560, use the 168/328 settings).

The for SdFat, had to make the same kind of changes for pin mappings, and callout the slave select line properly.

Took a few tries with several back & forths with fat16lib & others to understand it all.
Designing & building electrical circuits for over 25 years. Check out the ATMega1284P based Bobuino and other '328P & '1284P creations & offerings at  www.crossroadsfencing.com/BobuinoRev17.
Arduino for Teens available at Amazon.com.

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