search

mkeller0815 / MEEPROMMER

EEPROM / EPROM programmer based on Arduino hardware
http://www.ichbinzustaendig.de/dev/meeprommer-en
MIT License
66 stars 45 forks source link

Shift high byte of address bus first. #3

Closed pda closed 10 years ago

pda commented 10 years ago

The schematic at http://www.ichbinzustaendig.de/dev/meeprommer-en shows the low-byte address bus 74HC595 (EEPROM A0..A7) connected first, cascading into the high-byte 74HC595. This means the high byte should be shifted first. The code comments reflect this, but the actual code doesn't.

Note that @presslab-us's fork shifts the high byte first, although he says he didn't specifically change the address byte order. I'm not sure how it crept in here - probably while experimenting for a board with the '595 chips wired in reverse.

mkeller0815 commented 10 years ago

My first prototype had the shift registers wired in reverse order. I've changed this in the first schematic and later in the code. I can't say how this old part of the code came back into the firmware. Thanks for correcting.

pda commented 10 years ago

No worries - thanks for the merges, and for the initial code!