Testing

I hear ya: "Sure, when I get my monome working I'll become a world famous musician with groupies all around the world and enough cash-money to shake a large stick at - but when will I ever get to do the bad-ass cool sh!t like testing my PCB board???"  Right now!! "AWESOME!"

To test that the LEDs are all ok, I made a really simple light circuit.  I have 3 volts going through a resistor (50 Ohms (green black black) at least if using 3 volts - I used 1k Ohms (brown black red) so the LED brightness wouldn't mess up the pictures), then the positive wire (on the right) connects to one of the other LED legs & you get red, green or blue.

To test the board that was just soldered, just bring the negative line (the line that the LED cathode was in) to the LED grounds on the PCB board.  These are marked LED-GND1 through to LED-GND4 on the underside - I didn't have to solder these in place, they worked ok for me just held there.

Now bring the positive line to the contact marked RED1 and row 1 should all light up red!  Keep testing for the other colours and on the other rows too.

 

Any rows or LEDs not lighting up?  Make sure the cathode is in the right place and the solder joints are making decent contact.

Next you can test the diodes & switches.  There are tiny little holes you can do this test from but I found it easier when I snipped all the diode legs, put the button pad on and put the board upside-down.

Using your multimeter set to 2000 Ohms resistance (or the diode tester if you have a model with the diode symbol on it (looks like ->| an arrow against a line)), connect red to SWITCH4 and black to SWT-GND4.  You should initially get a 1 readout (meaning no current is getting through).  If you push down (so the button is being pressed) the readout should change (mine went to 700ish) meaning when the button makes contact current passed through.

Repeat this for all the other buttons by moving the red to SWITCH3 and testing the button second down from the left and so on.  When you get to the bottom, move the black to the next ground SWT-GND3 and move the red back up to SWITCH4.

Is the whole thing broken?  Does nothing work?  About to throw it all away and set fire to my blog?  WAIT!!!  All is not lost, you've made your first instrument, the pluckome, possibly inspired by this rainbow episode.  Just pluck on any legs you haven't clipped yet - now go and impress your friends!!

Soldering

This might seem over-the-top basic to a lot of electronics-able people out there but it took a little working out for me because I'm an eejit so just in case it's helpful to others, here's the solder job.

I usually like to dry fit everything first then do the soldering in one go.  There's a few ways the RGB LED can go into the PCB, the right way is facing up (doesn't make sense to illuminate the inside of your monome - although it would be more minimal) and with the cathode or ground of the RGB LED connected to ground.  The picture below shows how they should go in.  The longest leg goes into the second hole over if the board's oriented so you can read the text the right way up.  On the underside the longest leg should go back to GND (ground) the circuit is highlighted in the picture on the right.

Definitely not like this:

You need a small bit of force to push the LED in place (you need a lot more if you do it the wrong way).  There are little ridges on the LED legs which will sort of slide into place when it's in properly.  The LEDs shouldn't fall out if you turn the board over.  You can put the button-pads over the LEDs and push each of them to make sure none of the LEDs are sticking up too much.

The diodes then go in on the underside of the board (the opposite side to the LEDs) so the top side of the board is nice and flush for the button pad.  I bent the diode first (see the pic), slid it in then bent the legs to hold it in place.  It's really important to ensure they are orientated the correct way (the stripe has to match the stripe on the PCB).

Next the solder - the PCB holes are tiny and really close so it's difficult to get the solder to connect to just one of the little buggers.  If you're totally new to soldering, it'd make sense to practice on a cheaper project first.  A really precise soldering iron helps and one that's temperature controlled would be really handy as well.  I found a de-solder pump really good for fixing mistakes.

Some basic tips:

• Apply heat to the part you're soldering, not the solder itself -  otherwise you end up trying to drip the solder in place
• Don't apply too much solder - it should connect all around the hole with a little raised area sticking to the leg
• Use a damp sponge to clean the iron tip when it gets clogged
• Don't leave the iron on too long - the solder will boil and spit

I never really knew what the difference between a cheap soldering iron and a temperature controlled one was, I just presumed it was a pro thing until I saw a bit of solder boil on contact with the iron and spit everywhere.  A sensible reaction would be to close your eyes or look away, I, however, widened my eyes in surprise.

So if you have a temperature controlled soldering iron or you don't have inappropriate reactions to dangerous scenarios - read on!  Otherwise, I feel your pain.

If you're confident enough in your work, snip all the legs - if not give it a quick test first (next post).  Personally I find it easier to fix something if the legs aren't snipped.

Shopping 0.1

I've called this 0.1 because I'm sure there'll be a ton more trips to the electronics shop before I'm done.  As I'm by no means an expert, I started out with a list form Julien Bayle's site - but couldn't get some of the components at the links he suggested, so found other sources (I'm in Ireland by the way):

• 1 Arduino board 1 x $34.95 from Sparkfun (Julien's supplier link only deliver to France unfortunately)
• 4 Sparkfun breakout PCB 4 x $9.95 from Sparkfun
• 4 Sparkfun buttons pads 4 x $9.95 from Sparkfun
• 4 Sparkfun buttons bezel 4 x $9.95 from Sparkfun (I didn't bother with the bezels myself)
• 64 RGB LEDs common cathode 64 x $1.95 from Sparkfun
• 64 Diodes Small Signal (1N4148) 64 x $0.15 from Sparkfun
• 1 MAX7221 (LED Driver) 1 x FREE!! free samples from Maxim-IC
• 1 74HC164 (8-Bit Serial-In, Parallel-Out Shift Register) 1 x €1.60 from CPC (Farnell had a minimum order limit)
• 1 74HC165 (8-Bit Parallel-In, Serial-Out Shift Register) 1 x €1.64 from CPC

If anyone reading this has found better sources post them & I'll update the list - thanks!

You'll also need some basic soldering stuff (easy enough to pick up in any electronics place):

• Soldering iron
• Solder
• Multimeter
• Breadboard
• De-solder pump
• Variable power supply
• Resistors - a variety pack will do for now
• Jump wires

Monome Clone

Hi, I'm a total electronics amateur but I thought I'd give making a monome clone a bash.  I have always wanted to get back into playing music, but didn't know where to start...  It would cost millions to get my music collection on vinyl and start mixing, I tried out a few free mp3 mixers and didn't like them much.  A friend showed me Reason and it's fantastic so far, but I was on the lookout for a physical device that would make making music easy and fun... then I saw the monome...

I've wanted a monome ever since I saw Daedelus play, but the guys that make them are inundated with orders.  They're not cheap but 100s of them sell out within 24 hours of being available!! They're not even taking any more orders.  So, part in desperation and part in persuasion from my Dad, I decided to try to make a clone.  Besides, it should be fun (if I don't solder my fingers together or something like that).

The monome (pronounced mon-ohm) is a really cool, minimal, grid of back-lit buttons which can be hooked up with software to play samples & make music.  I think it's best shown off with a little demo (I think this might even be Daedelus himself) - it's best at about 1:11 in:

There are a good few others out there making clones too so I'm not doing anything original.  They're posting all their progress too, but as I'm a total amateur I can't guess some of the steps they skip.  I figure I can have a go at following their instructions and post my progress step-by-step here and it might help others like me.