DIY Arduino SD/Real Time Clock Expansion Shield

Forum 2005-2010 (read only) General Exhibition
1

Hi,

Because I want to log some data for my motion sensor, so I made a SD/RTC expansion shield for my arduino.

First, I want to thank sirmorris, sheepdogsoftware and other friends in this forum who gave me advices.

In this shield, I use a 74LVC245 as level shifter to transform 5V signal to 3V signal, and a DS1302 chip for Real Time Clock.

This shield uses arduino PIN 4(CLK), 5(DATA), 6(CS) for RTC and SPI PIN 10, 11, 12, 13 for SD module.

following is the schematic and PCB for this shield:


You may download the EAGLE schematic and board file for this shiled from here:
http://wells.osall.com/files/download.php?id=3924

This shield can be made with single layer PCB. The SD slot and 74LVC245 should be soldered on the top of PCB, and the DS1302, crystal and CR2032 can be soldered on the back of PCB.




for the code to use this shield, you may referrence following URL:

DS1302 RTC: sheepdog software Reading RTC in nuElectronics Data Logger Shield for Arduino - ar3ne1rtc
SD module: SDFAT Library Google Code Archive - Long-term storage for Google Code Project Hosting.

Hope this shield is useful to you.

Thanks~~~ :sunglasses:

BR,
Wells

2

Nicely done.

If only this was around before I ordered a couple of Seeedino Stalkers which have an RTC and microSD onboard.

Thanks for sharing.
Mark

3

Awesome etching :). What process did you do to get the protective layer?this by far best diy pcb I've seen!

4

@chris mitchell,

What process did you do to get the protective layer?

I use UV solder resist ink to make the protective layer. It's like oil and if use UV light to expose, it will change from liquid to solid.

First, I printed solder pads of this PCB on a transparent plastic paper (this transparent paper is often used for projector). This printed paper will be used to screen the UV expose for the oil on the pads.

Then I put some UV solder resist oil on PCB, about 1 - 2 ml.
Then put the printed transparent paper on the PCB and the oil (the oil is between PCB and plastic paper), and use a credit card to scrape the plastic paper to spread and smooth the oil.

After that, align the printed plastic paper with the pads on PCB.

I did not have a UV light, so I put the PCB with oil and plastic paper under the sun light to expose ;D. In sunny days, after about 10 minutes, tear off the plastic paper, you may find the oil become a solid layer, and after clear the oil on the pads (oil on the pads will not be exposed because the printing ink on the transparent paper screened the UV light) the PCB protective layer has been created sucessfully. :sunglasses:

-- sorry for my poor english.... :-[

BR,
Wells.

5

I use uv light, transparency paper, copper clad, negative film resist that's laminated on the copper. Long process. But I like yours. Where'd you get the supplies?