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Hi everyone,
starting from the mBed schematic I produced my own design with a LPC1758, but I soon found out that the RTC does not work (yes I don't use a probe on the XTAL lines and yes it's a recent revision A which should have no problems with RTC). I tried various combinations of crystals and capacitors:
http://it.rs-online.com/web/search/searchBrowseAction.html?method=getProduct&R=672-7631 http://it.rs-online.com/web/search/searchBrowseAction.html?method=getProduct&R=667-6108 http://it.farnell.com/jsp/search/productdetail.jsp?SKU=1838935
but none has given me stable operation. Are there any catches with the 32.768kHz crystals and LPC17xx? Does anybody know which make and model is the mBed one? I guessed from the schematic it should be an Epson-Toyocom FC-135 but the actual package marking on the mBed does not give me a lead on which part exactly... moreover, is it normal that the FC-135 options are 7, 9, or 12.5pF and the mBed uses 18pF caps?
Sorry for the long question and thanks in advance!
Cheers, Michele