Instructions - VMC-1
!!! PRE RELEASE DRAFT Hardware!!!
This is a
preliminary manual. It
is based on prototypes only.
Requirements of the final hardware may cause changes in the described
I will not
explain soldering. This kit is not
really difficult to solder, but I do not recommend it as a first
project. The order of the soldering is important. Some parts will hide
the solder points for other parts. If you mount the parts in the wrong
order, you will lock out yourself from finishing the module. Also
I strongly recommend to obey the mounting instructions for the sockets
and potentiometers with the help of the frontpanel.
Requirements and tools:
- a clean work bench with good illumination
- soldering iron 25W-30W; if possible a soldering station with
- tin-solder; the PCBs are lead free. Of course lead free tin
nice for the environment, but mixed lead/tin-solder is much easier to
handle, and it is still allowed to non professionals (at least in the
- electronic side cutter or microshear like the "Knipex Electronic
- midsized combination pliers
- midsized side cutting pliers
- screw driver with 3mm blade
Not necessary but helpful:
- a 2cm strip of clear adhesive tape (used for mounting the LED)
- a "helping hand" pcb holder
- a bending jig made from a strip board pcb:
I use a small piece of strip board pcb as bending jig. It is cut into
sections with two, three, and four holes between the parts legs.
All parts on the pcbs a designed for this standard grid.
Basically we will solder parts in the order of their heigth. As
mentioned above some parts will hide the solder points for other parts.
So keep the following order:
- First the rear side.
- resistors and diodes
- sockets for the arduino (see remarks in the detail section)
- voltage regulator
- pinhead rows
- power socket (optional)
- Then the front side.
- momentary switches (see remarks in the detail section)
- 3,5mm sockets(see remarks in the detail section)
- display (see remarks in the detail section)
- potentiometers (see remarks in the detail section)
- Then mount the frontpanel
- LED (see remarks in the detail section)
Details REAR SIDE
The resistors may come in two different physical sizes (0.3W and 0.6W).
The wattage does not matter for the functionality (with one
exception!). It is
simply a question, which size was available while buying. I prefer the
larger 0.6W types, but sometimes only the smaller ones are available.
10 Ohm or wire jumper:
This resistor controls the brightness of the display backlight; so it
has influence on the power consumption of the module.
If you don't have
to care for the power requirements then, simply use a wire instead of
this resistor. You may use a wire that you have cut from some other
resistor. The display backlight will be pleasing bright.
This resistor MUST be of the 0.6W type!
These 100 Ohm resistors are optional; if you do not want to use them, then replace them by jumper wires. Those resistors are used to separate the
incoming ground from the local ground. I found that to be very helpful
to suppress groundloop caused hum. My software for the VMC-1 takes
those resistors in account. If you transfer other software, like
software that was written for the MIDI-Shield, then you have to adopt
it to the slightly different minimal voltage.
These should be soldered before
the 47k resistors!
These should be soldered before
the 47k resistors!
These should be soldered after
the 100R and the 470k resistors
The diodes are a little difficult to distinguish. The devices name is
printed on both of them but if your eyes are like mine, then you will
need a magnifier.
Diodes have to be placed in the the right orientation. There is a black
ring around the glass body. It must point in the same direction as the
black mark is on the pcb diagram.
you will find written
on the glass body
Click on the image to enlarge.
You will finde a "5V1" written on the glass body
Click on the image to enlarge.
The black ring on the glass body must point to the right.
The Trimmer comes with legs for upright mounting. You have to bend the
legs 90 degrees to mount the trimmer horizontally:
Socket rows for Arduino
The sockets must be placed really vertically. They tend to fall over to
either one or the other side. You can urge them to stand really upright
with a simple trick: while soldering insert the 2x8-pinheaders across
the sockets and remove the pin headers afterwards.
I advise against using the Arduino itself for this task!
Keep the orientation of the
in mind. On of the three transistors at the sockets
"looks" into a different direction!
I recommend to solder the center pin of the transistor first, and then
the outer pins.
There are two capacitors. One round electrolytic capacitor of 10uF/25V (short "elco") and one rectangular foil capacitor 10nF/16V. Obey the orientation of the elco
Depending of the body style of the elco its legs must get bent:
Also the outer dimensions may be so large, that it is not possible to
connect the USB cable, if the capacitor is soldered in vertically. In
this case I recommend to mount the electrolytic capacitor in a lying
The white(or light grey) strip on the electrolytic capacitor must point to arduino
The foil cap may come either with narrow legs or wide legs. The pcb is
designed for both variations. If your kit contains the variation with
the narrow legs the cap has to be placed at the most right possible
The ON-position (required for the regular operating mode) is pointing
The pcb is prepared for a power socket. Using this you may run the
VMC-1 as a standalone device with an external 9V-DC wall wart. I found
that I never use this powersocket on the pcb, but usually I use a
separate power socket in the housing of the device. So I do not deliver
the socket anymore. Instead the following picture shows where to solder
the plus and the minus lead coming from the external power socket.
If you want to use the socket on the PCB: it is a "Lumberg NEB21R".
If you want to use an external socket I recommend the "Lumberg 1614 19"
That's it for the rear side!
Details FRONT SIDE
For the momentary switches there are two possible positions in relation
to the front panel: sunk-in or slightly raised.
You may be used to the raised position from other modules. The sunk-in
position avoids unwanted actuation and is equally in handling (to my
If you want the raised position then seat the switch only on the pcb,
without pressing the contacts through the pcb. Then solder the contacts
on the front side
on the pcb
(same side as the switch is placed).
If you want the sunk-in position then seat the switch on the pcb and
press it through the pcb. Then solder the contacts from the pcbs rear side
Place the sockets on the pcb and solder only one pin of each socket:
Mounting the potentiometer on the pcb is the most tricky part of this
First you have to bend the rear support for 90 degrees:
Then place the potentiometer on the pcb. You will see that the metall
bottom of the potentiometer is very close to the pins of the socket row
for the arduino.
Now cut the corresponding pins with the micro shear or the side cutter
Finally solder the middle pin of the potentiometer. Do NOT solder the
pins or the mechanical clamps.
There are four black spacer blocks. Mount them to the pcb of the
display with the M2.5x4 screws (the picture shows only two of them):
Now place the single row pin header in the VMC-1 pcb and place the
display on the pinheader. Fasten the lower end spacers on the VMC-1
pcb. Don't worry: There are really only two holes for it in the pcb! It
is not a mistake. Now the pin header should sit rectangular in the LCD
Solder the pin header to the display pcb.
Then turn the complete module to the other side and solder the pin head
to the pcb
LED and Final Positioning
- Put the LED in place but don't solder it yet. The longer wire must be placed in the lower hole.
- Place the frontpanel on the pcb and fix the potentiometers and the
sockets temporarily with their nuts.
- Position the LED in its hole in the front panel and bend its wires slighty aside
- Turn the module on its face
- Solder the LED wires
- Solder the remaining pins of the sockets and the potentiometers.
Press the knobs on the switches and the potentiometers
Seat the arduino in its socket.
Connect the Arduino Nano with a USB cable to a USB powersupply or your
computer. => The display should be lit, but assumingly you will not
see anything. Now turn the multiturn trimmer clock wise. It may take
ten or more turns until a row of 16 dark rectangles appears:
Now turn the trimmer back (= counter clock wise) until the rectangles
start to fade out:
This is a course setting. You may correct this setting after you have
loaded software on the Arduino
That's it. You are done.
Now read the VMC-1 owners manual how to transfer the desired software
to the module.