Rockdudes MegaDrum attempt (Build log)

[rockdude]

Yes, if a polarized header is not supplied.

I'm out of polarized headers so I guess the pins are to be used then. But I guess it would work just fine to solder the wires right on the button board without pins like I did with the lcd? I wish Synthex had provided pictures on a complete 32 and 24 inputs board soldered and done and the same goes for the keyboard buttons

I'm almost done soldering and connecting all connections, so this baby might be ready for a testride this weekend maybe
Before that I have some question on how, why and where to use jumpers, but I'll save those for later. I really appreciate all help I've received so far! Without the support from you guys I would be a miserable man with a broken board...Now I have hope!!!!

[jman 31]

Yes, if a polarized header is not supplied.

I'm out of polarized headers so I guess the pins are to be used then. But I guess it would work just fine to solder the wires right on the button board without pins like I did with the lcd? I wish Synthex had provided pictures on a complete 32 and 24 inputs board soldered and done and the same goes for the keyboard buttons

I'm almost done soldering and connecting all connections, so this baby might be ready for a testride this weekend maybe
Before that I have some question on how, why and where to use jumpers, but I'll save those for later. I really appreciate all help I've received so far! Without the support from you guys I would be a miserable man with a broken board...Now I have hope!!!!

If there is no header provided, he probably means for it to be soldered directly as you stated. It doesn't really matter as the other end is removable from it's header.

[jman 31]

Actually Rockdude, I got to looking it over, I believe those header pins are to be used for the "pedal polarity" and the "pedal impedance" holes. Those require a jumper, so you will need them there!

[rockdude]

Actually Rockdude, I got to looking it over, I believe those header pins are to be used for the "pedal polarity" and the "pedal impedance" holes. Those require a jumper, so you will need them there!

Thanks for pointing that out jman! I'll place them in the pedal polarity and pedal impendance holes instead. I'll be back later regarding the jumpers. What does a jumper do exactly? I have now clue about those. I've seen a picture of a board having one placed on two of the pins in "Power selection" if I recall correctly. Something tells me that it's there to tell the board to use usb power instead of an external source of power.

[jman 31]

That's correct. You will use the jumpers for "pedal impedance" , "pedal polarity" and power input (as you stated). A jumper simply completes the circuit for a specific point in the circuit depending on what hardware you choose (hi-hat pedal)

Pedal impedance will be something you get into when you decide what pedal you will use. Pedal polarity simply changes the power supply of the pedal from the tip to the ring. This is also something that will be determined by the pedal you choose.

[rockdude]

That's correct. You will use the jumpers for "pedal impedance" , "pedal polarity" and power input (as you stated). A jumper simply completes the circuit for a specific point in the circuit depending on what hardware you choose (hi-hat pedal)

Pedal impedance will be something you get into when you decide what pedal you will use. Pedal polarity simply changes the power supply of the pedal from the tip to the ring. This is also something that will be determined by the pedal you choose.

I'm using a DIY variable A to E hihat. It's based on Beatniks variable hihat (http://derksens.com/E-drums/Beatnik/Var ... roller.htm). I'm using a 50k ohm potentiometer instead of the 100k ohm Beatnik has in his build.
Can I just move the jumpers around and test what's best for my build or can I by mistake ruin something with a bad combination of jumpers in "pedal polarity" and "pedal impedance"?

So if I put the jumper like this, usb will power the board?:


What about "Power supply" on the Synthex board. Should I put a jumper on that too?

When I know everything is working and such, I want to use a on/off button (http://www.electrokit.se/images/minisw.jpg) to switch my MegaDrum on or off. How do I accomplish that?

And one last question
How do I know how to connect the led?

[jman 31]

I'm using a DIY variable A to E hihat. It's based on Beatniks variable hihat (http://derksens.com/E-drums/Beatnik/Var ... roller.htm). I'm using a 50k ohm potentiometer instead of the 100k ohm Beatnik has in his build.
Can I just move the jumpers around and test what's best for my build or can I by mistake ruin something with a bad combination of jumpers in "pedal polarity" and "pedal impedance"?

You really shouldn't hurt anything by moving the jumpers around. I'm not sure how impedance is calculated on the megadrum, but I would assume that it is a low impedance pedal. Pedal polarity will either work or it wont.

So if I put the jumper like this, usb will power the board?:

Yes.

What about "Power supply" on the Synthex board. Should I put a jumper on that too?

No. That is for hooking the alternate power to.

When I know everything is working and such, I want to use a on/off button (http://www.electrokit.se/images/minisw.jpg) to switch my MegaDrum on or off. How do I accomplish that?

I would cut the positive line from the inputs board to the main board and put an in-line switch.

And one last question
How do I know how to connect the led?

One way it will work the other way it won't. The flat side of the LED will go to the "1" and the round side will got toward the "+" You can't hurt it either way. It just won't work if it's in backwards.

[rockdude]

One way it will work the other way it won't. The flat side of the LED will go to the "1" and the round side will got toward the "+" You can't hurt it either way. It just won't work if it's in backwards.

Aaah to easy! I don't know why I think everything will go dynamite if I put it in the wrong way.
Thanks for all the answers.

I might be able to have my board ready for a testrun tonight if my wife falls asleep in front of the tv after the food is eaten and the wine bottle is empty.
It will be a nervous moment when I plug in this MegaDrum. If it works I'll be in heaven...and if it doesn't I'll go:
http://www.uniquedaily.com/andy-samberg ... he-ground/

[jman 31]

Aaah to easy! I don't know why I think everything will go dynamite if I put it in the wrong way.
Thanks for all the answers.

I might be able to have my board ready for a testrun tonight if my wife falls asleep in front of the tv after the food is eaten and the wine bottle is empty.
It will be a nervous moment when I plug in this MegaDrum. If it works I'll be in heaven...and if it doesn't I'll go:
http://www.uniquedaily.com/andy-samberg ... he-ground/

You will be fine man. These are very low voltages that we are working with so the worst that could happen is maybe to fry an IC or pop and electrolitic cap. Even these are not going to dynamite anything.

[rockdude]

Some questions before I try my board tonight:
Is it safe to unplug it before turning off the computer?

Is it ok to for example unplug a cable from one input and inserting it in another input while the board is on? I ask this because I own a Alesis Trigger IO and the manual only recommends operations like that before turning it on.