DIY PCB Fabrication

I was impressed by bjkayani's instructable Beeduino ,the tutorial is well detailed and also Thomas Fischl's USBASP.I decided to make both these circuits on one board.Not by soldering a perfboard or on breadboard but on our very own built PCB!! Yes we can make it at home!! I will show two ways of etching PCBs and also tell which one would be better. Enjoy!!

Step 1: How It Works??

1. The atmega 8 converts the usb to serial,part of usbasp.
2. Usbasp can be of two types 6-pin or 10-pin nothing different!
3. Here an external simple MCU circuit has been made.
4. Most arduinos operate at 5v of usb but using a voltage regulator i.e 7805 we regulate any voltage upto 12 volts.
5. We had used 16 Mhz crystal oscillator,internally the IC contains 8 Mhz clock but needs external one for faster processing.
6. The push-button changes from 5V to 0V (or vice-versa) only when it is being pressed down, which is for a few milliseconds usually.

This is a little introduction of what we are making.

Step 2: Things We Need

For PCB etching :-

• Ferric chloride/HCl and hydrogen peroxide (Ferric chloride from school lab and HCl from hardware store,Hydrogen peroxide from medicine store)
• Single-sided copper clad board
• Photo laser sheets
• Electric Iron
• Laser Printer
• Rotary tool with needle like usually 0.8 mm drill bit
• Plastic container
• Cutter
• Gloves
• Mask
• Safety for eyes

General tools :-

• Soldering iron
• Nipper

Misc. :-

• USB cable from B-type to Ordinary
• Acetone

Step 3: Printing Circuit

Here are some eagle and express pcb files.Print them on Glossy paper side and cut out the printed portion.The MCU circuit itself was desined by bjkayani.I used the same.Here is the cirucit of USBASP as well as MCU. Here is a video complete video of pcb etching tutorial by Make.

Step 4: Sanding

Using scrubber or sand paper rub the whole copper clad board to remove any oxidization or stains.

Step 5: Printing

Set the iron to maximum heat and then place the sheet on glossy paper and iron the sheet smoothly for about 15 minutes,then you will get proper print.In the picture this one is failed print,if this happens scrub it again using scrubber or sand paper.Try again!!Cut off the extra copper clad board.If you are using ferric chloride as etchant then no need to retry the toner transferring,shade the left lines using permanent marker.

Step 6: Safety!!

Safety is must while doing etching HCl and ferric chloride both can stain anything that comes in its way and also choose a well ventilated place for etching the PCB.

Step 7: For HCl

If you choose HCl and hydrogen peroxide then it would be safe to apply a coating over the print like that of marker or polish.Dip it into 50-50 solution of hydrogen peroxide and HCl the solution would turn green the green salt is copper chloride which can be used again for etching PCb by dissolving it in HCl !! It would take about 1 hour if you are using HCl with 30% concentration.

Step 8: Ferric Chloride

Ferric chloride is better choice because it etches faster and more perfectly than the previous method.Take about 40 grams of ferric chloride and dissolve it in about 100 ml water.The solution must appear brown without board and when we dip it appears somewhat yellowish in color.Not a chemical reaction only reflection of copper!! Dip in it for about 15-20 minutes till the full PCB etches!!

Step 9: Congratulations!!

Take out the copper clad board from the solution and then wash it under water and pour some acetone on board removing the toner,you would see a beautifully etched PCB.

Step 10: Drilling

Use a needle like drill bit between 0.8 mm to 1.2 mm and you would require 3 mm drill for drilling the holes for dc jack and dc ports as well as voltage regulator.Drill carefully a small mistake can break lines of your hand-crafted PCB.

Step 11: Start Soldering

Switch on your soldering iron and solder all the components as directed in schematics and PCB layouts.First of all solder resistors and then other components.

Step 12: Soldering Tips

Don't apply too much solder all little quantity enough to make the pin and line in contact would be enough!!

Step 13: Soldering Other Components

Bend the voltage regulator IC and also check the stability of every component.Check again if any component is left to be soldered.

Step 14: Done Soldering!!

Cut off extra pins of components and insert the ICs now and it is the time to test our device!!

Step 15: Checking

It is always a good idea to check everything before powering it on. I would suggest checking the continuity of each trace using a multimeter.

Step 16: Done!!

Thanks for seeing my instructable!! This is a very cheap and homemade solution for those costly arduinos. I have 2-3 Arduino but I love this one as it has been made by me! I hope you like it!! You can ask if you have any questions!!

Please vote if you like this!!

Thank you!!

Bye!!

Comments

[diy_bloke]

Your circuit doesnt look like there is an atmega328 in it, but then suddenly it appears on your PCB.
Seems a bit overkill to use these two chips for one arduino.
No need for any bootloader?

[grassmt]

I know it's fun to build your own, but you can buy the Uno

<$5, Nano <$3, and Pro mini <$2. What is your time worth?

[Gursimran Singh 425]

Ya but here I have to face shipping charges with import duties!! :-)

[geekrex]

UNO costs around 350 rupees you dont need to think of duty and secondly using two mega is not a good idea.

[geekrex]

those are not uno

[_Boltz_]

i got mine for 150 INRs from chandni chowk , i bought 3 from there.. :D

[grassmt]

If you order from AliExpress the shipping is usually free. What would the import duty be on a $2.00 item? I'm fortunate that they don't worry about the little items that come in from China. It's not worth their time/effort to keep track of them. What country do live in?
I made my own stripped down board for Arduino, but then the prices of the Arduino dropped. So, I don't bother building them. Question: If something is shipped to you that is a gift/free, what is the import duty on it?

[Gursimran Singh 425]

I'll try but last time when I received my arduino kit I had to pay 20$ while receiving even after I paid import duties because the package was from china!! For liitle things I had even paid more than the product costs,safety glasses,arduino due etc.In india I pay these if anything arrives from other countries!! It was just an idea to make own production version arduino,I still use arduino uno r3 for my projects!! I am working on a project that has a whole circuit assembled in two parts.I can use these circuits not the programmer inly MCU.:-)

[IanB40]

If you don't like using acids and etchants, building it on perf board using wire-wrapping tool and wire would be an alternative. I used to build prototype circuits this way, when I worked in an electronics factory. You might have to solder some connections if the tags are too short for the number of turns used for a wire wrap joint. DIL sockets are available with pins suitable for wire-wrapping, or pairs of SIL connectors, suitably cut to length could be used. Cheap Arduino boards from China would probably be cheaper, but building one yourself, even if on breadboard, will definitely improve your understanding of the circuit.

tags are too short

[Gursimran Singh 425]

Right!! Good approach!! Ya i'll try it in its v2.0

[Duxtal]

hey, very great project ,very intersting :D | 1 problem ,how to open the .pcb file ?

[kedwa30]

Great 'ible! I was just wondering if anyone has ever tried making this as compact as possible by not using a board at all and what it would look like. Also, do you know about the ESP?

[rjawale]

It is possible to make the board more compact by using SMD devices. But sometimes the SMD packages are difficult to solder by hand.
ESP8266 is already compact but it is difficult to solder pins. You can make your custom adapter for ESP.

Check my ible on SMD soldering
https://www.instructables.com/id/SMD-Soldering-SOIC...

Also check my other instructables and do vote for the IoT based one if you like it.

[RobertH230]

18 steps to make a light light up?

[rpotts2]

@RobertH230, 18 steps to create an AVR circuit that doesn't require a dragon or ISP. Dude, it's a good circuit.

[Gursimran Singh 425]

Thank you!! Glad you liked it !! :-)

[daniels351]

Looks like a very fun project that I may do in the distant future, but for all my control projects I would rather just buy a bunch of $2 mini atmega328 Chinese clones and 1 $3 programmer on ebay and use them instead.

However, this would be a fun project just to do by itself, except the pcb etching, being a mechanical engineer I would rather design and build a small pcb cnc with cd drives than use caustic chemicals (a pcb cnc is my next project after I finish my laser etcher and my aluminum/wood cnc).

[Gursimran Singh 425]

Glad you liked it!! :-)

[BernyM1]

Impressive. Thanks.

[Gursimran Singh 425]

:-)