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Topic: RFID simple logger onto SDcard (Read 1 time) previous topic - next topic


Hello my Arduino pals...

now i'm not one to just get things done for me... as all my life i've taken things apart to see how they worked and it's not stopping anytime soon... but sometimes you need a nudge in the right direction...

the thing I want a bit of guidance on is dealing with the different hardware i've assembled for my project...

the outline of the project is use rfid tags as a timing system the arduino needs to read the tag and store the tag id on an SD card (logging the time which comes from the dallas 1307 rtc)

the idea is to use mifire rfid tags (not because i want to store any data on the tag, but just it was the cheapest RFID reader i could find on ebay... )  this is the reader specs..


and the rtc board..


and my sd card is on the ethernet shield (which i cant find the specs for right now)

now i've got some code that reads the cards... but it's massively complex... and i'm looking for a bit of guidance on how i should be interfacing the boards...

i know that the rfid board is SPI, but can i have that on the spi bus, and two other items on the ic2 bus working at the same time..

please drop me a line if you can offer any help..




I'm worried by the "massively complex" comment - do you mean you looked in a library and got confused?  If so just read the documentation for it and the examples and don't worry!  There are several libraries though so look to see what other projects use/recommend (search the forums for instance).

Using several devices on I2C or SPI busses is normal, that's the meaning of "bus".
[ I will NOT respond to personal messages, I WILL delete them, use the forum please ]


Maybe the shudder that ran down my back when i opened a project file to read the card and found it too be 850 lines long... Whoooh....

the concern i have with the three items i want to interface is that they are a mixture of i2c and Spi so i want to understand if there are any limitations i should take into account...

the main one being what will happen if a card arrives at the reader and i'm reading the RTC... will i have a problem???


Dec 15, 2011, 09:35 pm Last Edit: Dec 15, 2011, 09:42 pm by padstar Reason: 1
here is the demo code..  Attached

this is all I've got in the way of demo code...no other instructions... and even with the readable comments, i cant fathom what's going on.. 

... and I've tried to cut it down to just read the card id... but alas.. i cant seam to get it working simply... :-(


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