Search found 5 matches

by kricon
Wed Oct 31, 2018 4:56 am
Forum: Hardware
Topic: SD Card pullup resistors, atmega 644 programmer, few questions
Replies: 15
Views: 8891

Re: SD Card pullup resistors, atmega 644 programmer, few questions

The ESP8266 and the SPI Ram are fairly easy to add to an E/Uzebox. I did it on a prebuilt official E/Uzebox PCB from Hartmut with some jumpers. I'm making my own PCB (maybe stupid idea without testing it on protoboard first), and wanna know if there is any disadvantages if I just add SPI-RAM and ES...
by kricon
Tue Oct 30, 2018 4:25 am
Forum: Hardware
Topic: SD Card pullup resistors, atmega 644 programmer, few questions
Replies: 15
Views: 8891

Re: SD Card pullup resistors, atmega 644 programmer, few questions

I didn't remove the resistors, since it looks like they're just used for level conversion (5v -> 3v3). And yeah, adding the pull-up resistor to MISO fixed the issue with the new bootloader. I was busy on an trip away from home and life things get in way so left the project 'in a drawer' for a while...
by kricon
Wed Sep 26, 2018 7:30 am
Forum: Hardware
Topic: SD Card pullup resistors, atmega 644 programmer, few questions
Replies: 15
Views: 8891

Re: SD Card pullup resistors, atmega 644 programmer, few questions

I was rethinking about those resistors and would play safe and remove them to be identical to the standard circuit and not conflict with the 644 own pull-ups etc. Can I ask you, when you'll have some spare time, to do testing with 10k miso, mosi, sck and sd_ce pullup resistors (if possible, with uz...
by kricon
Tue Sep 25, 2018 4:24 pm
Forum: Hardware
Topic: SD Card pullup resistors, atmega 644 programmer, few questions
Replies: 15
Views: 8891

Re: SD Card pullup resistors, atmega 644 programmer, few questions

Hi! I am not an electronic expert, hope someone comes along who can provide some better answer. However I think those pull-ups shouldn't have any adverse effect, so you can keep them, but you should most likely get rid of the 3.3V regulator, as there is (should be) one already on the Uzebox PCB, an...
by kricon
Mon Sep 24, 2018 5:31 am
Forum: Hardware
Topic: SD Card pullup resistors, atmega 644 programmer, few questions
Replies: 15
Views: 8891

SD Card pullup resistors, atmega 644 programmer, few questions

I was following (e)uzebox project for few years and I finally managed to get all the required parts so now Im ready to start making my homebrew euzebox, and I have few questions (with more to come along building, for sure). Just now soldering, and I have LC Technology SD card socket module with inte...