http://openschemes.com/2011/06/06/h...ner-chapter-1-homebrew-usb-card-readerwriter/
i need a pcb design based on this so i can get it manufactured for my use
i need a pcb design based on this so i can get it manufactured for my use
- Thread starter werejag
- Start date
Want To Buy
https://github.com/wifiber/Xyron-Card-Reader
I whipped this up just now, check it over and see if I made any mistakes. I noticed in my KiCad footprints, that none of the included SD card footprints have a pin 13. Also, in the referenced link, there is a schematic where I believe the pin numbering might be wrong on the SD card. It seems to skip over pin 13 and has a pin 14.
So I was good up to pin 12, then I hit discrepancies in Kicad and the referenced schematic with pins 13 and 14.
If you need any changes let me know and I will see what I can do
I whipped this up just now, check it over and see if I made any mistakes. I noticed in my KiCad footprints, that none of the included SD card footprints have a pin 13. Also, in the referenced link, there is a schematic where I believe the pin numbering might be wrong on the SD card. It seems to skip over pin 13 and has a pin 14.
So I was good up to pin 12, then I hit discrepancies in Kicad and the referenced schematic with pins 13 and 14.
If you need any changes let me know and I will see what I can do
1. The voltage issue is really not resolved at all - It just taps the power from the Teensy which is probably 5v. I can put a little voltage reg IC that will go 5-> 3.3 to fix this issue. Wasn't sure if there was a way to run the Teensy on 3.3v and solve it that way.
2. That was the first time using that full sized SD card footprint, but I believe I got the SD opening on the edge of the PCB.
3. I can swap out JP1 for a pin header rather than solder pad.
2. That was the first time using that full sized SD card footprint, but I believe I got the SD opening on the edge of the PCB.
3. I can swap out JP1 for a pin header rather than solder pad.
I have a few options for SD card footprints in the default KiCad library, I am using part: TE-2041021
https://www.te.com/usa-en/product-2041021-1.html
Some others I could choose:
Kyocera: 145638009211859+, 145638009511859+, 145638109211859+, 145638109511859+
I choose the TE part since it had pins 1-12 at least clearly shown, those kyocera parts seemed to be missing pins.
I added a 3.3V regulator and changed the J1 jumper to a pin header style. Also, moved the gerbers to a proper folder.
https://github.com/wifiber/Xyron-Card-Reader/blob/master/sdInterface.pdf
https://github.com/wifiber/Xyron-Card-Reader/blob/master/sdInterface.png
PS - I am choosing not to pour a ground plane on this board as that connects to the 4 corner pads (pin 12) to the ground pins on the SD card (pins 3, 6). I figure if you need to isolate the 4 corner pads (pin 12) from ground, you could easily break a trace or two - if there is a ground pour, you'd have a much harder time isolating the corner pads if needed.
https://www.te.com/usa-en/product-2041021-1.html
Some others I could choose:
Kyocera: 145638009211859+, 145638009511859+, 145638109211859+, 145638109511859+
I choose the TE part since it had pins 1-12 at least clearly shown, those kyocera parts seemed to be missing pins.
I added a 3.3V regulator and changed the J1 jumper to a pin header style. Also, moved the gerbers to a proper folder.
https://github.com/wifiber/Xyron-Card-Reader/blob/master/sdInterface.pdf
https://github.com/wifiber/Xyron-Card-Reader/blob/master/sdInterface.png
PS - I am choosing not to pour a ground plane on this board as that connects to the 4 corner pads (pin 12) to the ground pins on the SD card (pins 3, 6). I figure if you need to isolate the 4 corner pads (pin 12) from ground, you could easily break a trace or two - if there is a ground pour, you'd have a much harder time isolating the corner pads if needed.
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https://www.mouser.com/_/?Keyword=2041021&FS=True
Mouser shows lots in stock of all the different dash versions, so I think the SD card slot is good, no? It is the larger standard SD slot, so I wonder if most the larger SD slots are NRD (not recommended for new designs) since its the older size/style.
You're right on the orientation, I will flip it 180 degree. Mounting holes should be no prob.
Mouser shows lots in stock of all the different dash versions, so I think the SD card slot is good, no? It is the larger standard SD slot, so I wonder if most the larger SD slots are NRD (not recommended for new designs) since its the older size/style.
You're right on the orientation, I will flip it 180 degree. Mounting holes should be no prob.
