Hardware description: SD interface (self made)

If you don't want to spend money (and support RadioClone project ;)), you can try to build SD card interface. Unfortunately I can not guarantee that it will always work. Sometimes you need to use other resistors values​, or adding additional pull-up resistors to achieve the desired effect.

Parts List

  • micro SD card adapter
  • strip header - angular (90 deg)
  • LD33V - voltage regulator 3.3V (low drop)
  • 3 x 3V3 zener diode
  • 2 x 10K ohm resistor
  • 3 x 1K ohm resistor
  • 2 x 100n F capacitor
  • universal PCB at least 10 x 10 pads (or better 10 rows)
  • 30 cm network cable (4 pair)
  • 30 cm telephone cable

Schema

At the beginning I must point out, that this scheme strictly experimental. I built three of them, but only 2 works .. I suppose it did not meet the specifications of the voltage and some resistors need to be replaced for larger / smaller.

Board

I used an universal PCB. Black lines indicate GND (ground), orange Vcc 3.3V (power supply)


SD Slot

I used the SD adapter for micro SD. I made the conversion by soldering angular strip header (90 degrees).


Elements Soldering

Next I placed flowing elements
  • 3 x 3V3 zener diode
  • 2 x 10K resistors
  • 1 x 100n F capacitors
like on picture, then solder it (see second picture how). All connection are lined up.


soldering


Soldering SD slot

Place SD slot and rest of the components (like on the picture)



soldering


Wires

Please use that same colours for the cables (further description will then be compatible with your board). Wires of such colors is available from cable and telephone cable.


soldering


Installation

Wire naming schema:



Wiring diagram of transmitters motherboard



Module after installation


Last edited on 02/21/2012 18:40:28
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