Russ15 megadrum build

[Russ15]

This is my first attempt at soldering, pcb making, buying electrical components, etc... but here is my take so far on my build. I am attempting to make this very beginner oriented like how I began.. including tips, products, and anything else I can help others with.

Main board design: Synthex v 2.5 All-in-one board with Input jacks v 1.8

After doing tons of research time here on the forum I decided to jump in and try my luck at making the pcb required for this. This pcb design can be found here viewtopic.php?f=3&t=198

There are a few different methods of transferring the images in link above, however I used to toner transfer method described here http://www.youtube.com/watch?v=urv6jArKp6M
I did not have access to a laser printer so I printed the PCB 2.5 bottom viewtopic.php?p=4223#p4223 and PCB inputs 1.8 viewtopic.php?f=3&t=462 multiple times on an inkjet printer, cut them out, and attached them to sheets of printer paper with clear tape. I also did not have the right kind of paper for the transfer onto the copper so I went to Kinkos and bought a few sheets of their photo/magazine paper ($.70 each) You can then just make a photocopy of your sheet with the taped pcb images onto the photo paper and you are all set (at Kinkos or on any machine that has toner). If given the option to darken the image (use more toner) try to get the maximum to enhance the amount of toner transferred onto your photo paper. This will help when transferring it to your copper.

Next step was to iron the image onto the copper board. I bought a 4x6 piece of copper http://www.allelectronics.com/make-a-st ... ARD/1.html like this and picked up a used iron at a thrift store for five bucks. I didn't want to use my iron as it was brand new and wasn't sure if it would ruin it or have any other repercussions.
I cut out the image I wanted to use from the photo paper and taped the sides to the front with tape so the paper would hopefully not shift during ironing. Pick a surface that you can put lots of weight on.. I used a wood workbench so there would be no give.
Next i put the iron over the paper and copper board and put all my weight on it for around thirty seconds. After this time I used the tip and sides of the iron, while applying a good amount of force, to get every area on the paper where toner was present. I did this for 5 minutes total and until I could see the image transparently through the paper.
After this I threw the entire thing in a bowl with water for 10 minutes (careful it's hot!). I then went back and peeled off the major layers of paper until there was a sort of film of paper still there and let it sit another 10 minutes. I then went back and rubbed my fingers over the copper and used an old toothbrush to get as much paper off as possible (This took a while and I was pretty thorough).
At this point you want to check to see that the image looks exactly like the original... no lines that didn't connect all the way or if anything is missing. You can use a sharpie to connect broken lines and such, but you can see how small the lines are and how accurate you have to be. I failed on my first attempt and had to do it again, but got it the second time. Got it? Now on to etching.

For the etching bit I used muriatic acid and hydrogen peroxide. 2 parts hydrogen peroxide (8 oz) to 1 part muriatic acid (4 oz). The original video I watched on this is located here ( just the etching bit) http://www.youtube.com/watch?v=VtmWaxzgoK8. I found this be thorough and pretty straightforward from the video. Wear gloves and protective equipment and make sure you are using a plastic container as muriatic acid will eat right through metal.

When this was through and everything looked good I used ammonia (nail polish remover)....... lacquer thinner actually works best....... and q-tips to remove the remaining toner to reveal the copper. Here is an example of how it should look after viewtopic.php?f=3&t=542 Done!

Drilling:
Next step for me was drilling holes in the pcb. I didn't own a drill press which would make life easy, so I borrowed a hand dremel from a friend This one to be exact http://www.amazon.com/Dremel-3956-02-Mu ... roduct_top. As you can see it has an extension to a smaller pencil type drilling device which helped tremendously.
I bought the drill bits from harbor freight http://www.harborfreight.com/20-piece-s ... 44924.html I used the 0.8 mm bit for everything but header holes which i used the 1.0 mm bit. I used two rubber tipped clamps to hold the pcb in place and a 3/4" piece of mdf wood as a backing. Key is to take your time and go straight up and down. I was far from perfect on many holes but as long as you don't completely destroy the pad I think you are in good shape.

Buying components:
I used the list that gastric and Synthex put together located here: viewtopic.php?p=3960#p3960

Disregard the pot 10k trimmer... newest firmware allows to adjust brightness. Instead you will need an extra 100nf capacitor, 10k resistor, and 1k resistor... more on this here viewtopic.php?p=19252#p19252

Disregard ATMEGA664-20PU this you have to get from Dmitri... contact him via pm to find out how or get in on a group buy on the forum for a discounted rate.

Disregard the DB25 Male to construct the ISP cable (not needed since you are getting the Atmega from Dmitri already programmed) and the 4 220 resistors needed with that.

Everything else is fair game! I got most of my components from a local electronics surplus store in town and the rest will be ordered from mouser.com

Checking your board:
Ah yes probably the most time consuming part of the build... checking all your traces for continuity. Before populating the board with the components I had I went and checked every single line and pad on my board. I didn't think this would be a big deal but soon learned that what looked like a perfect board to the naked eye had many traces touching each other!!! At least five (before soldering). I count this as part of the build because I feel it is essential.
HUGE thanks to Jman31 for this... it will show you where each pad and line is connected to so you can test them with a multimeter to make sure they check out and aren't touching any other lines viewtopic.php?p=6326#p6326. I blew up the picture he has here and checked each trace and pad off as I went and made sure they were not involved with any other trace or pad. If you know nothing of multimeters here is a good video start on how to use it and where to get one http://www.youtube.com/watch?v=bF3OyQ3HwfU

If lines were touching each other I simply took a utility knife and cut the copper out that was touching the other line or pad so only that line gave me continuity and not across multiple lines. This is really impossible to see with the naked eye and only a multimeter can tell you if copper is touching another trace. This takes some serious time and trial and error, but it will prevent the headaches after soldering and help you know what to look for if something goes wrong.

Populating the board:
Simply follow the top picture, mind polarity (circle pads are negative, square pads are positive), don't forget the jumper wires.
viewtopic.php?f=3&t=198

A populated board: http://www.italentshare.com/forum/viewt ... 4ee27f#p88

Soldering:
I bought this station here http://www.amazon.com/Elenco-Soldering- ... B0002KW4AC and is plenty for this project.
The solder is .032" 60/40 rosin core from radio shack: http://www.radioshack.com/product/index ... Id=2062719
Also got some desoldering wick for any mistakes: http://www.frys.com/product/4833170;jse ... IN_RSLT_PG
Lastly I picked up a "third hand" tool similar to this one. It really helps when soldering and the magnifying glass really helps when looking at traces http://www.amazon.com/Soldering-Third-H ... B0030UUVR4

Watch this video before starting and for tips: http://www.youtube.com/watch?v=I_NU2ruzyc4 .
I also bought a practice soldering kit to test my skills before taking on solder the components on the megadrum board. http://www.allelectronics.com/make-a-st ... KIT/1.html
I would recommend doing this as any mistakes you will take out on something that really doesn't matter and you will learn the technique and what heat works best with your iron.

Programming PIC
Well after everything was soldered in it was time to program my PIC. I used PIC18F2550, which I would recommend. To start off you will need to use a computer with a serial port built in. You can use a pci card, but those are pretty expensive and in my case, this would be its only use. You will need a serial cable as well. For me I needed a female to male cable like this http://www.homanndesigns.com/store/inde ... age&pID=26.
After all these things are in place, hook up your ICSP cable up to the correct headers to program the PIC. For the rest of this section I refer you here http://www.megadrum.info/content/programming-mcus. Keep in mind if the WinPic says Error programming failed, this might not be the case and the only way is to check for proper voltage readings...viewtopic.php?p=10476#p10476.

Tips:
Make sure your board whether it be a jacks board (synthex) or digital board (dmitiri) is hooked up to usb power when doing this.
After you program the PIC, unplug you ICSP cable and just use usb power to see if your computer finds megadrum.

Loading Firmware
If your computer now detects megadrum it's time to load firmware. First download MDUpdate here viewtopic.php?p=14818#p14818. Next get the latest firmware here viewtopic.php?p=13066#p13066. Lastly watch this video here to complete the process. http://www.youtube.com/watch?v=Y8M3KIRuPWQ

That's it... well at least as much as I know for now haha! Next step would be configuring everything which can be found here http://www.megadrum.info/content/megadrum-configuration

Cheers!

[kupooglop]

i am curious. why did you use synthex pcb design when dmitri has an up to date 56 input all in one pcb that supports the external eeprom?

http://www.megadrum.info/forums/viewtopic.php?f=3&t=1623

i am unable to rationalize using a pcb design that has a history of being associated with problems related to it being outdated and no longer supported?

http://www.megadrum.info/forums/viewtopic.php?f=3&t=1595&hilit=synthex+pcb+problems

again, just curious. no ill will towards you, synthex, his design or the people that use it.

[Russ15]

Honestly when I started looking into building a megadrum I looked at my needs for a kit ( I have played drums for 17 years and have moved into a place where I cannot have an acoustic set so I know how big and what I need for my kit) and I only needed a 32 input module.

Secondly I had no idea this pcb even existed. The only documented, tested, and all-in-one diy pcb I could find when I started looking in this forum was the Synthex v2.5 kit for the 32 input module I needed. I tried to contact Synthex before I began to get pricing on an all in one kit, but it seems he is MIA so I decided to give what I had gathered on my time in the forum a try.

I wish I had known about this design before I started, but so far this has been a great project and yes it has taken some good dedication to get things right thus far but I am hopeful things will work out in the end.

By the way what is the purpose of the eeprom in the new design posted?

[kupooglop]

that is what i was thinking. a lot of new forum members are not aware of dmitri's updated pcb schematics when they start building their megadrums.

To the best of my knowledge the eeprom was added to give extra storage room for multiple drummaps and configurations.

either route chosen requires the dedication you mentioned. as long as you keep working at it, i'm sure you will get good results.

[Russ15]

Update 8/20/2011 - Finished soldering the board minus the headers for the 18F2550 programming cable... picking up a 47k resistor to attach to pins 3 and 6 tomorrow and will solder on.
Also finished ICSP cable for programming the 18F2550

[Russ15]

Finished the main board and input jacks.
Pictures are of wires connected to pins 4,5,24,and 25 of Atmega for rotary encoders, 47k resistor hooked up between pin 3 and 6 of the PIC ICSP headers, and input jacks.
Almost done just need to wire up things, program PIC, and eventually get my Atmega from Dmitri. (I'm in a group buy right now, just need 2 more people!)

[Russ15]

Finished all the wiring that needed soldering and the lcd...almost done!

[timekeeper]

Very nice job!

[Russ15]

Finished making the input jack back panel. Went to a dollar storage and bought a plastic storage container with moderately thick plastic and cut out a section that is equal to the original metal piece (you can see it in the photo above). Drilled out the holes and it was as simple as that! Once everything is done I want to do some labeling for all the inputs.

Thanks timekeeper!

[Russ15]

Project finally completed! Big thanks to all who helped me out during the build.... timekeeper, Jman31, and especially Dmitri. Big credit to Synthex for the design and for all those who posted up their documentation on this project. I look forward to building my set now! Here's a link (viewtopic.php?p=19825#p19825) to the megadrum gallery showing the finished product! Thanks again for a great product Dmitri!