I am having a weird issue with the enc28j60 controller and atemga8. I am trying to build this circuit:
I am using this schematic to power up the circuit with a 9V battery:
(all the capacitors are actually 10uF)
The enc should respond to ping but I have to plug in/plug out the battery a few times before it works. Also it seems that when I add a new battery it doesn't work at all. Only when I use a slightly older 9V battery (multimeter tells me it's 7V) it works from time to time.
Any idea why is this happening since both lm accept a wide voltage range ?
Best Answer
I can't find a datasheet on that dev kit, but I think I know what the problem is.
If you go to the datasheet of the IC and look at Figure 2-4, it shows that you will need a level shifter to bring the 3.3V output of the SO pin up to 5V so that the microcontroller can read it. This is true of the /INT and /WOL pins as well.
If you're lucky, then your specific microcontroller can also be run at 3.3V. Check your datasheet. If so, then just power it from your 3.3V rail, and there shouldn't be any problems.
If not, then there are a lot of options out there to perform the level shift. If you need help with this, please post another question :)
Good luck!