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Hi Group,
I've been having some trouble with the level shifter between the SD card and the 74LS299 Shift Register. On advice from a friend, he suggested I just route the 3.3V signal directly into the 74LS chip. Apparently, this is how it's done on the Arduino shield. I did this and it works perfectly. This mod requires 1 cut trace, and 1 jumper. I have updated the schematic with various IC, resistor and capacitor values It also has the mod described and shown. I am presently working on the BIOS and a manual for this board that should include the BOM and this recent MOD. Please find the latest schematic on the share site at: http://n8vem-sbc.pbworks.com/w/file/82620064/JAIR1SCH-Production%20Rev1.pdf Cheers, Josh Bensadon |