Product Page - http://xiwielectronics.com/products/pushi-kit-modi-system
GitHub Repository - https://github.com/brendan-byrne/Modi
I. Hyrbi Assembly
II. Pushi Assembly
III. Turni Assembly
IV. Slidi Assembly
To assemble this kit you should have introductory knowledge of electronic components and basic soldering skills. You will need a soldering iron, solder, wire strippers, and flush/angle cutters. Solder wick is recommended for correcting mistakes.
YOU CAN DO IT:
If you are worried about your soldering abilities, watch a YouTube “how to solder” video. I recommend this one from Curios Inventor https://youtu.be/IpkkfK937mU
For questions, concerns, or problems related to kits from the Modi Controller series please contact, Brendan Byrne, at firstname.lastname@example.org.
1 - Pushi PCB
2 - 4051 Multiplexer ICs
2 - 16-Pin IC Sockets (not pictured)
2 - 10k Resistor (100k shown)
2 - .1 uF Ceramic Capacitors
16 - Pushbuttons
16 - Pushbutton Caps
1 - Male Straight Pin Header
1 - Male Right Angle Pin Header
1 - Female Straight Pin Header (not pictured)
1 - Female Right Angle Pin Header
6 - 1/2" Hexagonal Standoffs
6 - 4-40 Pan Head Screws
Some images in these instructions use other boards from the Modi series. They reference components found across all boards such as the connectors, integrated circuits, and path selection channels. Do not be alarmed if your board is different from the one shown.
PCB POPULATION I - 4051 ICs
This kit includes IC sockets for the 4051. However, if you plan to build an acrylic enclosure for your Modi controller (instructions coming soon) you will need to solder the chips directly to the PCB. Either way you will be soldering all the pins of each IC. Below are three approaches for getting the chip to sit flush with the PCB.
a. Hold and Tack
Pull some solder out from its coil and let it float in the air. Insert the chip into the PCB correctly and then hold it in place with your non-dominant hand's index finger. Position the soon-to-be-soldered point on the PCB next to your solder. Make sure the solder extends a few millimeters past the joint. Apply the iron and watch the solder curl back and melt into the joint. If you are using loose solder, you can also use helping hands. This is a good way to have it hover in place. See video below.
b. Gravity and Balance
Set the 4051 into the PCB correctly. Flip the board over and let the weight of the board keep the IC in place. You may want to apply pressure to the board on either side of the IC's pivot point so that it doesn't move around too much. First, solder two opposite corners of the chip and the proceed with the remaining pins.
c. Flux Pen Alternative
If you have a flux pen on hand, apply some flux to the joint. Pre-load your iron with solder before applying it. Be sure to clean the board once you've completed assembly. Certain kinds of flux can be corrosive to the PCB.
Tape the IC into its position. Solder a few pins, preferably those not touching the tape itself. Remove the tape. Solder the rest of the pins.
PCB POPULATION II - RESISTOR
Pushi uses two pull-down resistor. The first is positioned directly beneath the button to the left of the bottom 4051. The other can be found at the top of the PCB in line with the first. You will find that the spacing of these holes is off by a little bit. I apologize for this and plan to fix it in the next iteration of the board. Fortunately, it will in no way effect the functionality of the unit.
SAVE BOTH SNIPPED LEADS OF THE RESISTORS!
They will be used later to set the ICs channel.
PCB POPULATION III - CAPACITORS
Capacitors are located to the top right of each 4051 socket. Inset the capacitors, bend the leads, snip, and solder.
PCB POPULATION IV - CHANNEL SELECTION BRIDGES
Next we will solder the channel selection bridges into place. These points allow you to choose what Modi signal path the IC will send potentiometer or button information on. More detailed information on this can be found in the Wiring section of this manual.
On the left side of the PCB you'll find the numbers 1-8 between sets of solder points. Numbers 1-4 indicate what paths the top IC will transmit on and numbers 5-8 represent possible channels for the bottom IC. On the Slidi PCB, numbers 1-8 are for the single IC. These numbers do not affect the code of your microcontroller. They have been placed to assist you in planning your system electronically.
If you plan to use more than one Modi module than DO NOT TO USE THE SAME CHANNEL PATH MORE THAN ONCE. If you have made this mistake, you will receive messages from two banks of controllers. This problem will reveal itself when it comes time to program the device.
Visualizing Path Selection
The image below is an example of a Modi system composed of three interconnected modules. The five colors indicate signal paths. The elongated grey ovals in the selection area indicate channel selection bridges. This unit supports 5 4051 multiplexers for a total of 40 readings. Take note that no path has been used more than once.
Making A Path Selection
Remember the leads you saved from the resistor? Bend those leads into the shape seen below. These do not have to be perfect. They will be inserted into the numbered slots. Use this image as a rough gauge for shaping the wire.
Insert the leads into the path you'd like to send on. CREATE ONLY ONE BRIDGE SELECTION FOR EACH ROW. In the example below, the top multiplexer will send its signal on Path 2 and the bottom will send on Path 6. Each of these paths is associated with a pin of the connector that we will be adding next. If this is your first Modi module, it is recommended that you use channels 1 and 5.
PCB POPULATION V - TOP CONNECTORS
You will have to decide whether you want to use the male straight or right angle pin header. Both sets are included in the kit.
Choose this option if you want to plug your Modi PCB directly into a breadboard. Works best for whatever module is at the top of your system or if you plan to use one Modi board.
b. Right Angle
Choose this option if your module will be daisy-chained and located beneath another module. Keep in mind that you can still connect a Modi unit with right angle pin header to a breadboard (see image below). If you have female pin header of your own or you don't plan to use the female pin header that came with the kit, you can plug them directly into the breadboard. Take note that not all breadboards are alike. Test to make sure right angle female connectors will fit into your board before deciding this method. They have a habit of popping out on some breadboards.
This is a good example of how integrating your controller into a breadboard allows you to build interfaces on the fly to suit your evolving needs. Here, I am utilizing the breadboard to visualize MIDI input messages using a few LEDs. Hyrbi board shown here.
c. Wired Connectors or Straight Female Pin Header
If you are planning to create an enclosure for your system, consider mounting your microcontroller underneath the Modi PCBs. In this case, using a wire connection will be the best approach. It also works well for directly connecting to an Arduino. Alternatively, use the straight female pin header positioned on the face of the PCB. This will allow you to use jumper cables to connect your microcontroller.
SOLDERING PIN HEADER
Regardless of what pin header type you use, you will still need to solder it in place. The connectors that come with the kit must be broken into sets to match the PCB. First, we will snip the male pin header. Create sections of 5, 4, and 4. The best tool to make these sections is the flush cutter. Do your best to cut without destroying any pins.
In this photo, I plan to solder the 5V pin into place. My index finger does not touch this pin. DO NOT TOUCH THE PIN YOU ARE SOLDERING! YOU WILL BURN YOURSELF!
Make sure the pin header goes in straight and flush with the board. The holes allow for some wiggle room, so after you've soldered one pin, it won't be too difficult to heat that joint back up and readjust the header. Applying pressure with your index finger pushes the pin header into a straight position.
PCB POPULATION VI - BOTTOM CONNECTORS
If you intend to use only one module, then you can skip this portion of assembly. Otherwise, this is the key component in linking Modi boards together.
When you cut female pin header you must take into consideration that one pin will be destroyed. Center your flush cutters on the sacrificial pin. Snip the right angle female pin header into sections of 5, 4, and 4 pin sets.
In this image I am cutting to create a section of 5 pins. Note that my flush cutters are located directly upon the 6th pin from the right, which will be destroyed.
Solder the female connectors into place. Try to keep them flush. The hold and tack solder trick described above comes in handy here.
I am about to solder Pin A into position. My solder is floating using some helping hands. All I need to do is apply the the soldering iron.
PCB POPULATION VII - BUTTONS
Place the buttons into the PCB. Flip the board over and solder their pins in place. Take a moment to check your board against the images below. Now is the time to fix mistakes if you see any.
If everything looks good, then add the button caps. Take a moment to consider the underside of the caps. They can fit 1 of 4 ways. If you think you're applying a too much pressure, you most likely are.
STANDOFFS + SCREWS
This is the easiest and final part of assembling your Modi kit. Take one screw and place it through any of the mounting hole slots of the PCB. Hold the screw in place using one of your hands. With the other, grab a plastic standoff. Rotate the standoff clockwise to quickly screw it firmly into place. Repeat this process for the other positions.
Next Section: Wiring