One body building up with 3.5 inch HDD for file server

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Edited by ebiharasho at 2014-10-22 12:50

I built up a server of one body with bananapi and 3.5inch HDD.
This is based on two transparent acrylic panels, 180x125x3mm.
They are binded by metal spacers.
I like combination of transparent panel and shining metal.
This works with single 12V power supply.
DC/DC converter using LM2676S-5.0 generates 5V DC from 12V.
12V power to HDD is stopped while 5V DC line is under 4V.
NJM2903 comparator detects voltage and 2SJ681 controls on/off.
Great job! I like it!

Edited by dylan at 2014-10-22 22:47

I  like it very much,  the BananaPi board which system run on?

Raspbian and samba run on this.
I selected Raspbian because I am familiar with RaspberryPi.

Which throughput values in MBytes/sec to/from the SATA HDD do you achieve locally and through the network? Just curious since Raspbian should not be optimized for ARMv7 architecture but only ARMv6 and therefore not be able to perform at maximum speeds especially when used as a server...

I did test.

Load task
   write 52files, total 20.6GB from win7 PC to samba server.

  BananaPi (ether=1G, HDD_IF=SATA) 14min
  BananaPi (ether=100M, HDD_IF=SATA) 32min
  BananaPi (ether=1G, HDD_IF=USB2) 13min
  RaspberryPi (ether=100M, HDD_IF=USB2) 39min
  N2820 NUC ubuntu (ether=1G, HDD_IF=USB3) 9min

According to this result, bottle neck is not CPU and OS
optimization but ether speed, in the world of ARM small CPU card.
Intel CPU is in another world.

Unfortunately this series of tests is rather worthless Thx anyway

Great job , can you post here schema to your board ?

I'm sorry for long interval.
Here is schematic of the circuit shown above.
22uH inductor :  LHLC10NB-220K Taiyo yuden
Diode : HRF503A HITACHI, old stock
NJM2903 : compatible with LM2903

12V switch control can be simplified as follow.

I use 12V switch because I guess 12V circuit of HDD is controlled
by 5V circuit and so it is not good that 12V power only is supplied.
but it may be negligible.
By the way, I made another power supply circuit with PCB.
MP8715 is used because of newer design product.
Advantage of MP8715 and PCB make it compact.

This circuit is same as one of second schematic except MP8715 is
used to generate 5V. MP8715 circuit is same as manufacturer's
recomendation. 4.7uH inductor is used.
I tested that one bananapiand one HDD work with this power supply.

Edited by ebiharasho at Jan 15, 2016 10:52

Happy new year and how have you been.
I have proceeded a project to extend previous work to multi stage structure with SATA port multiplier
so I report it here. Three HDDs are attached and work.


The handle attached at top is sold for door but fits with this application.
Rebuild work is need to use SATA port multiplier. I refered these web pages. ... multiplier-support/
I followed the instruction shown there and got proper result.
Here is a screen shot of gparted on Xfce4.
Three HDDs, sda,sdb,sdc are identified and shown in Devices item.


The power supply is made by this circuit.

This circuit is shown as designed and used by me.
Use this information with user's own responsibility if one uses.
Thermal design is one of importand issue.Two points are considered.
One is thermal via and another is heat spread enhance by desoldering braid.
Templature of devices on the board is felt near human body during operation.


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