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In this instructable you I will teach you how to make a PCB breakout breadboard friendly for the Intel Edison Minibreakout with Iron and toner technique.
The concept of the Intel Edison is great, but require skills (some skills are very advanced) to start working with this tiny invention.
The concept of Sparkfun Blocks is great, but lack the access to all the pins of the Edison (else you will require several blocks). The Arduino board is a great way to start with Intel Edison, but is to big and breaks the esscence of the edison, besides that, this board don't have access to all the pins of the Edison.
So, is necesary to build a very expensive PCB (with very small traces and very small connector) to do an advanced prototype of the Intel Edison?
The response is: not, here is where the Minibreakout of the Intel Edison enters to the rescue, but not alone. The mini breakout is not breadboard friendly, but have others adavantages:
- Lipo management (charge and regulators)
- Serial and OTG connections
- Power Up sequence management
BBedison is a series of PCBs that allows you (in conjunction with Edison minibreakout ) prototype in a more friendly way.
The best of all:
- It's cheap: BBEdison base cost 5 USD (Yes 5 USD and you are ready to plug in your Edison in your breadboard)
- It's easy to do it in your home.
I will focus more in create the PCB than design it!, this instructable is long because I break apart several details and steps.
For this instructable you will require:
- 1 Drill Tool
- 1 mm drill head
- Glass Cup
- Ferric Chloride
- Permanent pen marker
- Iron Tip
- Wood table
- Scoth tape
- 1 wood thick table (In the drilling process)
- 1 10x10 Fenolic plate
- 2 lines of signel line of male of pins
- 1 line of doube line of male of pins
- 2 lines of female pins
- Solder Paste
- Tooth Brush
- Cloth or Burlap (for clean)
- 3 Letter Couche sheet paper or equivalent (you can use glossy magazine paper)
- Eagle CADSOFT
- Git knowledge (Github)
Estimating time: 3 hours.
Step 1: Design
The design part is very easy, fortunately, the edison mini breakout have standar breadboard pitch.
The only part that we need to do is trace the pin of the minibreakout to the outside.
I've done this for you (Note: I am using the 30 pin header model, this is why they are four pins with no connection at all).
And clone this repository (The PCB was made with Eagle Cadsoft, go and download if you don't have eagle), if you don't have git you can grab the files from here: .sch and .brd (right click, save as in the same folder).
I skipped the design part, the reason is because in youtube you can found thousands of videos of how to made a design with Eagle, the other reason is the design of this board is very easy.
Step 2: PCB 1: Printing & Scale Verify
This is a very (really very) crucial moment when you build home made PCBs.
- Clone the repository, or grab the .sch and .brd (right click, save as both in the same folder)
- Add the path of the cloned repository (or the folder), go to Control Panel->Options->Directories.
- Add the repository dir to the projects textbox, don't forget the " ; " to separate dirs.
- With the project opened, wee need filling the polygon (this is used to avoid excessive and unnecesary exposed copper), for this, go to Ratsnest option in the PCB window of the schematic.
We need to setup the correct scale of our printer, the scale change with the printer, if you change the printer you will need set again the scale, this is an iterative step (take from 6 to 8 iterations).
- Go to PCB windows in eagle.
- Go to File->Print
- Select scale at: 1 (our starting point)
- Check the scale (with a caliper or a line of pins), until the scale have a aceptable error.
- Choice a new scale (vey subjetive step).
- Go to 4 (print again)
Save the scale in a file (trust me), verify that you have check the "black" checkbox in the print window, put a Couche sheet and print.
We can tolerate some error (in later steps you will see some tricks that I use to compensate this error).
Note: I removed all the unnecessary layers in PCB window, this file is basically ready to print when you download it.
Step 3: PCB 2: Transfering the Toner
This is a very tricky step, first, cut a small part of phenolic plate (if is possible, with the same size as the printed circuit), you can use iron sheet scissors, but be careful you can easily damage the plate.
Clean very well from grease or other imperfections, (I highly suggest very fine paper sanding and wash with soap).
Use adhesive tape to fix the paper with toner to the phenolic plate, the toner needs to be face to face with the copper of the phenolic plate, try to adjust as tight as possible.
Borrow your iron, plug and set the temperature in the middle of the power (we don't need all the power), with the hot iron, pressure with force the iron vs the phenolic plate with the paper (lean in a wood table), start with equal pressure in the plate, and with the tip hot the outside parts.
If all is ok, you will see the parts where the toner melted and glue in the copper, to remove the excessive paper simple drop the plate in water, wait 5 minutes and drag the paper with you fingers. (Note: different paper take more time in water or requiere more force to remove the excessive paper).
You will get the transfered toner, but if you see with careful, you will see some parts where the toner drift and have contact with other traces, we need to fix this before the etching!.
If the circuit/toner don't have good look, you can remove with acetone and start again.
Step 4: PCB 3: Fixing Minor Details Before Etching
A common problem with Iron and toner technique is the fact that the toner melt and drift, so errors in the traces are very common.
To fix this problems we need a Razor, a pernament pen (with thin tip) and a little part of phenolic plate.
First of all, we need to know if our permanent pen works! (for some reason all permanent pens don't work as expected), so grab a piece of phenolic plate (junk) draw some lines and drop in the Ferric Chloride (see more of the Ferric Chloride in the next step).
If the pen pass the test we can move to our phenolic plate with toner, take the Razor and separate the crossed traces, if you damage to much the trace you can use the permanent pen to restore the damage.
Step 5: Etching the PCB
This is a very straightforward step, grab you Ferric Chloride solution, merge 2/3 of Water and 1/3 of Ferric Chloride.
Drop the phenolic plate in the mixture, I recommend use a crystal container, you can accelerate the etching if you have some heat source.
Clean the PCB of the Ferric Chloride with abundant water.
You can reuse the Ferric Chloride for your next PCB design, save it.
Note: be careful with the Ferric Chloride, don't expose directly in the skin or clothes.
Step 6: Drilling and Testing the Scale
This is the most cardiac step (is here where you see if your scale was really correct).
Before drill I prefer use a nail to make a little hole (this is like a guide for the broach).
Grab your mototool, hand drill, mini drill (name it in the way you like more), mine is a mini drill steren proskit 34, with a 1 mm broach, avoid use 1/32 inch is to small, avoid use 3/64 inch is a little big (with this broach is easy take apart the copper of the pad).
My broach is a Dremmel 1 mm, put the broach in your tool, grab a thick table of wood (for lean the drill process) an here we go! (don't worry, the hole that we made with the nail in the PCB is here for help us to drilling), for the moment only drill one line of the outside pads.
After drilling, grab a line of pins, cut 30 and (breath deeply) try to insert in the PCB.
If you can insert your pins line of 30 you can celebrate, we are reached the most critical part!.
If you see close to my photo of the pins and the PCB you will see two things:
- I pushed all pins in the way they only are in a one part of the plastic bracket
- The pins bends when you push to the bottom (due to the little scale missmatch)
We can use a line of header female pins to try to correct the bend (more of this in the step of soldering).
Finish the drill of the rest of the PCB.
Step 7: Remove the Toner and Tin the Exposed Copper
Take the acetone and good piece of burlab or cloth.
Wet the burlap with the acetone and wash away the toner (I highly recommend wash directly the PCB with the acetone and use the burlap to dry the PCB).
Grab and heat your Iron tip, solder and solder paste, take the solder paste and spread along the PCB.
Take your hot iron tip, touch a little of solder with the tip and try to spread the solder in the copper (repeat until all copper is covered).
Step 8: Prepare and Solder the Pins
We need cut the female headers, after cut, grab your drill and a cut disc and shape the rough parts.
To solder we need to ensure that our pins are in line (remeber that the pins can be bend due to the missmatch of the scale).
Grap a line of female header lines and put in the pins, this will ensure that the pins are in line, don't put the female headers to the bottom, remember we need solder the pads, displace the female header a little (ensure that the iron tip don't touch the plastic of the headers).
Solder with the iron tip (be carefull with your movements).
Apply the same method for the other pins.
To solder the female headers we need to keep in their place meanwhile we apply solder in the other side, grab a double line of male pins, align and insert the feamale pins in the male pins, put in the PCB and continue soldering.
Step 9: Clean the Solder Paste
Now we are ready to clean the residue solder paste, again, grab the acetone, take a burlap and a toothbrush.
Wet the burlap an put a generous amount of acetone in the purlap, drag along the PCB the burlap and use the toothbrush for the small or difficult parts.
Step 10: Solder the Pins to the Intel Edison
Take a double line header pin, cut two of 14 width, put in the female headers of the PCB, and check (really check) that the pins don't touch the metalic shield of the Intel Edison (push away with some tweezers).
Proceed to solder the pins to the breakout of the Intel Edison and finally, make a continuity test to ensure that the pins don't have a short circuit.
Step 11: Test All, We Did It!!!!!
Now, you can plug your Intel Edison in the breadboard, let's test something.
Go to the Sparkfun web site and follow this two Guides (Install Ubilinux and libmraa):
The hard part is find the correct pins in the breakout (I'm working on this).
After install and run you can see the above GIF.
What is next?
The next objective is drive a Drone Brushless Motor, stay tunned to the following accounts and this instructable!!!!
Thanks for your attention and happy wiring!!!!!
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