#avr Logs

Dec 19 2019

12:00 AM day__ is now known as day
07:54 AM juri_: has anyone here tried emulating an SD device with an AVR?
09:16 AM rue_mohr: SD!
09:18 AM rue_mohr: polprog, if you use white or blue leds, 10k will be fine
09:18 AM rue_mohr: you dont use back to back for polarity unsensitivity eh?
09:21 AM Fuchikoma: SD device? Like SD memory cards?
09:21 AM rue_mohr: yea, Its a bit fast for avrs I think
09:23 AM polprog: rue_mohr: hmm, i gould
09:23 AM polprog: could*
09:27 AM Fuchikoma: Isn't speed negotiation part of the protocol? You can maybe pretend to be an older card that operates at lower speeds
09:31 AM Fuchikoma: Apparently the "default" is 25MHz, and the ATxMega has versions up to 32MHz
09:31 AM Fuchikoma: So not impossible. Maybe not the best idea, but not impossible.
09:39 AM polprog: sd cards with avrs are pretty popular
09:39 AM polprog: they have SPI
09:40 AM polprog: you can run them as slow as you want
09:41 AM rue_mohr: but who is clocking
09:44 AM nuxil_ is now known as nuxil
09:57 AM juri_: right. this would be a raspberry pi clocking... so probably no dice.
10:17 AM Fuchikoma: I wonder if SD cards support clock stretching
10:21 AM skz81: SD Cards operate at two speed modes. The default mode clock speed is 0 -25MHz. A high speed mode is available at clock speed of 0 -50MHz.
10:21 AM skz81: https://www.cactus-tech.com/wp-content/uploads/2019/03/An-Introduction-To-SD-Card-Interface.pdf
10:22 AM Fuchikoma: Yeah and I thought the card itself was responsible for telling the host what speeds it was capable of
10:22 AM Fuchikoma: There has to be some way to negotiate that, or to slow down the communitations if there's a problem
10:51 AM aborazmeh_ is now known as aborazmeh
06:25 PM nuxil: Fuchikoma, perhaphs take a look at existing projects that already has sd card support? perhaps marlin. that firmware for 3d printers.
11:13 PM dan3wik is now known as dan2wik
11:58 PM day__ is now known as day