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Forum Index : Microcontroller and PC projects : sd reader no sd card
| Author | Message | ||||
stanleyella Guru  Joined: 25/06/2022 Location: United KingdomPosts: 2127 |
Really sorry to ask but I converted a sd card adapter to a breadboard reader and read sd card but then said "sd card removed" so bought 2 sd card readers , for arduino but logic is 3.3V, 2 for £4.80 but drive "b:" then files says no sd card. Wiring ok. tried swapping miso/miso.. says moso on reader. dunno if I contact seller as they may be fine. using vga usb 005b. PicoMiteVGA MMBasic USB Edition 5.09.00b5 OPTION SERIAL CONSOLE COM2,GP8,GP9 OPTION AUTORUN ON OPTION COLOURCODE ON OPTION KEYBOARD US OPTION CPUSPEED (KHz) 252000 OPTION SDCARD GP13, GP10, GP11, GP12  |
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| matherp Guru Joined: 11/12/2012 Location: United KingdomPosts: 9112 |
I'm afraid those "arduino" sdcard boards never work. You want a board with no components or just a capacitor across the power lines. Edited 2024-03-14 03:44 by matherp |
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| okwatts Regular Member  Joined: 27/09/2022 Location: CanadaPosts: 59 |
Not wanting to dismiss Peter's observation I did get this to work when I was attempting to get Mixtel90's little SD daughterboard working with the 2040Zero. I do remember some issue with these due to the different chips used to voltage translate on the module but I don't have the reference at hand. I would try a freshly formatted fat32 card (in a PC) and see if you get a different result. If you get the message that the SD Card is removed when extracting the card from the reader then at least the card is being recognized by the Pico/MMBasic. Some cards tend to be fussier than others. I found Lexar 633x cards (Which I have a number of) to be most difficult. |
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| stanleyella Guru Joined: 25/06/2022 Location: United KingdomPosts: 2127 |
B*****ks! thanks for the heads up, wasted nuff time. ebay recommendations for one that works from experience please. stan |
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| stanleyella Guru Joined: 25/06/2022 Location: United KingdomPosts: 2127 |
I tried 2 sd cards. one 2 wav files the other a bmp. they read with the soldered sd card adaptor for a minute then said sd card removed. on the forum "they are iffy". all the ili displays I own have sd card readers that work. actually thinking I never use sd cards so why bother and use the pins for summat else. I tried adding a 10uf to the sd card adapter supply but still got sd card removed. even a squirt of wd40 to clean same:)  Edited 2024-03-14 05:13 by stanleyella |
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| okwatts Regular Member Joined: 27/09/2022 Location: CanadaPosts: 59 |
Hi Just for reference I found the discussion saved as a pdf from a different forum that discusses the issue I noted with these adaptors. 6502spiadaptorissues.pdf |
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| stanleyella Guru Joined: 25/06/2022 Location: United KingdomPosts: 2127 |
interesting about mosi hi and cs after short time etc. totally baffled now. wire up a duff lcd just the sd card and use..no |
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TassyJim Guru Joined: 07/08/2011 Location: AustraliaPosts: 6098 |
search ebay for "sd card breakout" I ended up with a page of suitable boards with NO extra chips, just as Peter suggested.  Jim VK7JH MMedit MMBasic Help |
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Mixtel90 Guru Joined: 05/10/2019 Location: United KingdomPosts: 6785 |
This sort works fine. It has pullups and supply capacitors. I've used it several times. Otherwise, use one that has *no* chips on it, and preferably no resistors unless you know how they are wired. Mick Zilog Inside! nascom.info for Nascom & Gemini Preliminary MMBasic docs & my PCB designs |
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| okwatts Regular Member Joined: 27/09/2022 Location: CanadaPosts: 59 |
Just another followup I looked through my supplies and found an adapter with the other (T125A) chip and tried it with the same results. It appears that I have a card (Sandisk Ultra) that seems to be able to be read by either of the adapters. My lexars are read fine in the the PicoVGA v 1.0 from matherp and the daughter card by Mixtel90 but not in these adapters on the Pico. The takeaway for me is that these adapters are not reliable for all cards. I have not tried these modules in all other situations But I believe I used these with a Teensy a few years ago. |
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| Mixtel90 Guru Joined: 05/10/2019 Location: United KingdomPosts: 6785 |
The problem with the modules (designed for 5V Arduinos) that have chips on them is that they are designed for 5V systems. All SD cards are 3V3, so there is a LDO regulator on board. Unfortunately these have a minimum input voltage of around 3V5 at best (usually higher) and often nothing comes out of them (or it's a low voltage) when powered from 3V3. Additionally there are often level shifters, which shift the 3V3 signals from the SD card up to 5V. This makes a mess of the idea of powering the module from 5V and connecting the signals directly to a Pico. If you are *really* lucky you might find a module that will let 3V3 through the regulator (albeit unregulated) and with level shifters that work properly. In those cases the module might work, but results could be marginal if you swap SD cards. It's far easier to get the right SD card module in the first place. :) Mick Zilog Inside! nascom.info for Nascom & Gemini Preliminary MMBasic docs & my PCB designs |
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| stanleyella Guru Joined: 25/06/2022 Location: United KingdomPosts: 2127 |
I'll try that one if still available. Thanks. |
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| stanleyella Guru Joined: 25/06/2022 Location: United KingdomPosts: 2127 |
arrived today and works vga usb . thanks Mik |
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| stanleyella Guru Joined: 25/06/2022 Location: United KingdomPosts: 2127 |
it's small. messed up the board with arduino sd reader, tracks cut and wiring then unsolder it all but this was ok but wiring not neat, worked first time though and so cheap I got 2.  |
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