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Topic: enc28j60 no miso signal (Read 599 times) previous topic - next topic

socarto

hello, first i appologize for my english because i am francophone
i am making a home made board using this board http://www.drotek.fr/shop/fr/home/407-c ... 28j60.html which will communicate with pic18f4550 here is my scheme
the RST and CS are software programmed to RD1 and RD0. the program i use has been tested by mikroelectronica team and it is suppose to work. so i think my problem is from hardware. the seller of enc28j60 board confirmed that it work properly ( i have bought 10 items).
the problem i have is that the board does'nt respond to ping request.
when i look the signal on a scope, i see that MISO signal has a very strange behavior: when all wires are connected, there is no signal on 74hc245 A7 and B7 pins, when i remove wire between A7 and pic RB0 pin, i get signal. same, when i remove wire on pic RC7 pin.
also the green led on magjack sometimes turn off such as it's disconnected on my switch.
the enc28j60 board is supplied by 3.3V.
as don't have 3v3 regulator i use a laboratori generator and the scheme bellow to provide 3v3, i also try computer power supply, i even supply the pic directly with 3v3 but still the same problem.
another strange behavior, when put my hand close to some wire i have miso signal but no ping response. lenght of wires beetween enc board and pic board are less than 10Cm.
can you please help me?
thank you


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