CEB Press/Manufacturing Instructions/Controller Box/Construction Video Script
The CEB Press Controller Box is an electronic control box that runs the Compressed Earth Brick Press. Assembling the Controller box will require a drill with a twist bit, wire strippers, a flat head screwdriver, a Phillips head screwdriver, a small precision flat head screwdriver, a pen or something to mark with, a soldering iron, a soldering stand, and pliers. It consists of a Control Box, an Arduino Uno microcontroller board, an Arduino Breakout board, a PWM driver board, two screws that will fit through the Arduino board's screw holes, a spool of soldering wire, a paper towel which should be wet for soldering, two 100-ohm resistors, two light emitting diodes (LEDs) and a multimeter.
This video includes the most updated version of the CEB Press prototypes on the Factor E Farm. I will refer to the orientation of the controller box and the boards we will mount within it as the top of the box (where the lid hinges).
The first step is to prepare the controller box by gently bending away all of the wiring to hang out of the box so that the mounting platform is clear.
Next, temporarily and lightly mount the Arduino Breakout board to the Arduino Uno microcontroller board, matching the Breakout board's male pins to the microcontroller's female pins ... they may not mount perfectly at this point, but we just need to have an idea of how big the boards will be to help us place holes in the box's platform for screwing the Arduino board in that will still allow room to later connect wiring on all sides of the larger breakout board. Orient the boards such that the 'tops' of the boards (going by the text orientation) is actually to the left of the box, then place the mounted breakout board in the center so that there is as much space as possible between the sides of the breakout board and the walls of the controller box. Remove the breakout board while keeping the Arduino microcontroller board in the box on the mounting platform without moving it from where it would hold the breakout board centered in the box.
Make sure the box's terminal blocks in the upper left corner of the box are screwed in as tightly as possible.
Carefully mark two of the four mounting holes (either one from the top and either one from the bottom, preferrably in opposite corners) onto the platform; be sure to double check the position of the holes. Remove the Arduino board, and carefully drill holes through those marks. Mount the Arduino microcontroller, line up the screw holes with the holes you just drilled, and screw the board onto the platform. Be careful not to screw the board in too tightly, or the board may bow, bend and crack.
Next, we need to mount the Arduino Breakout board onto the Arduino microcontroller board. However, the USB port and the power jacks on the Arduino Uno microcontroller board prevent snug fitting due to the extraneous wires sticking down from the bottom of the perimeter of the breakout board, so snip the third, fourth and fifth perimeter bottom wire from the left and the third and fourth wires from the right of the bottom of the Breakout board. The short snips of wire may fly in unpredictable trajectories, so keep your eyes protected.
Next, we will connect a red positive voltage wire from the control box to the breakout board. Use the precision screwdriver to unscrew the terminal labelled "VN" at the top of the breakout board, which is the second from the right of that top terminal block. Insert the exposed end of the topmost red wire attached to the terminal block in the upper left of the Controller box, then rescrew the Breakout board's VN terminal screw back down tightly on the wire you just inserted.
Next, we will connect the black wire from the lowest terminal of the lower terminal block in the controller box's upper left to the leftmost "GND" terminal at the bottom of the breakout board using the same technique as before: unscrew the terminal screw on the breakout board with a precision screwdriver, insert the exposed end of the wire, and re-screw the breakout board terminal screw down onto the inserted wire.
Next, we will connect the two orange sensor negative wires to the two "GND" terminals that are the 5th and 6th terminals from the left on the top terminal block on the breakout board by unscrewing the terminal screw on the breakout board, insert the end of the wire into the open terminal, then close the terminal by re-screwing the terminal screw onto the wire.
Next, connect the two blue sensor positive voltage wires to the two "5V" terminals that are the 5th and 6th terminals from the right on the top terminal block of the breakout board by unscrewing the terminal screw on the breakout board, insert the end of the wire into the open terminal, then close the terminal by re-screwing the terminal screw onto the wire.
Next, connect the two white wires with blue stripes to the "A0" and "A1" terminals which are the 7th and 8th terminals from the top on the breakout board's right side by unscrewing the terminal screw on the breakout board, insert the end of the wire into the open terminal, then close the terminal by re-screwing the terminal screw onto the wire. Make a note of which which wire goes to A0 and which wire goes to A1, as they are different sensors.
We now need to solder the light emitting diodes or LEDs and the 100-Ohms resistors, so prepare your soldering equipment and supplies: The soldering iron, which needs to be plugged in to heat up and should be safely mounted on a soldering stand, so that the hot tip will not burn you nor start a fire by being left on a table; you will also need a spool of solder, two LEDs, two 100-Ohms resistors and a pair of pliers. You will also need a wet paper towel.
Soldering irons will easily burn skin, so focus, care and attention is critical for your safety. Fumes can be dangerous, such as the fumes from rosin flux which is at the center of soldering wire that prevents oxidation but is also corrosive, so prevent contact from the fumes with your eyes and avoid breathing it in. With your soldering iron securely on its stand, plug it in to let it heat up. It may take several minutes for the soldering iron to reach soldering temperature.
LEDs have two different wires going in versus going out, distinguishable by the lengths of the wires. The positive wire, which is longer, will be connected to a positive terminal while the other wire is negative and will be the wire we will connect to the 100-Ohms resistor. Using a pair of pliers, bend the tip of the negative wire into a small hook.
Make another hook in one of the two wires of the 100-Ohms resistor, and hook the LED and resistor wires together by those hooks. Use the pair of pliers to mash the hooks together; this will help make the process of soldering these two components together much easier.
Before we begin actual soldering, it is important to note that the soldering process will cause the LED and resistor wires to become quite hot. They will become too hot to touch, so do not handle the wires directly during nor after the soldering process; instead, use a pair of pliers. Also, electronic components can incur damage from too much heat, so you will need to solder as quickly as possible to avoid letting too much heat build up which may damage the components, especially the LED. Keeping a grip on the LED wire, on the joint side with the resistor, will help alleviate both problems as the pliers have much more mass and are more resistant to overheating, and will actually absorb some of the heat spreading along the wire and prevent damage to the LED.
Clean oxides from the surface of the soldering iron by wiping it against the wet paper towel.
Now it is time to set up to solder these two resistor/LED pairs. Set up your solder spool so that the end of the solder wire is bent up, so we can easily access it hands-free. "Tin" the soldering iron by touching the tip of the iron to the end of the soldering wire, just enough to get a small bead of molten solder at the tip of the soldering iron. This will help improve the transfer of heat from the soldering iron to the wires, where we will want them ... when we solder, we will not be touching the soldering iron to the soldering wire directly, but touching it to the wires, causing them to heat up so their joint can be touched to the soldering wire, melt the solder and absorb it in a bead. Touching the soldering iron to the soldering wire during the actual soldering process would draw the bead onto the iron instead of the wires where we want it.
Remember that the actual soldering process must go quickly, as prolonged heating of the wires with the soldering gun can damage the LED; also remember the wires will be too hot to handle with your fingers directly, so handle them only with the pliers. Do so now by gripping the LED joined with the resistor using the pliers on the LED side of the wire, and carefully grip the plugged-in soldering iron with your other hand. Heat the joint we made between the resistor and LED wires by touching the hot soldering iron near the joint, and quickly touching the joint, not the soldering iron, to the soldering wire. If the wires are hot enough, the solder will melt readily and draw up into the joint. Quickly remove the iron from the wire and replace the iron on its stand, and set down the resistor/LED to allow the solder to cool. The soldered joint should have a silvery luster, which indicates a good solder.
Repeat this process on the second resistor/LED pair, then clean the tip of the soldering iron by wiping it on the wet towel and then unplug your soldering iron to let it cool. Warning: It may take several minutes before the soldering iron cools to the point the tip would be safe to touch, so let it sit for awhile on the soldering stand.
Give the wires and their solder some time to cool before we handle them for the next step. After they have cooled, test the conductivity between the wires with a multimeter; they should have zero or almost zero resistance.
Plug the LED end of the two soldered LED/resistor pairs into terminal blocks 12 and 13 which are the two lowermost terminals of the breakout board's right terminal block by unscrewing the terminal screw on the breakout board, insert the end of the wire into the open terminal, then close the terminal by re-screwing the terminal screw onto the wire.
Connect the resistor end of the wires to the 4th and 5th terminals from the left of the breakout board's bottom terminal block by unscrewing the terminal screw on the breakout board, insert the end of the wire into the open terminal, then close the terminal by re-screwing the terminal screw onto the wire.
Mount the PWM board onto the breakout board. The PWM board will be orientated such that the six terminal blocks, the lowest of which will be pointed down instead of to the side as the others are, will be on the right hand side.
Take a piece of red 18-gauge wire long enough to reach from the rightmost terminal of the upper terminal block on the breakout board to the two down-facing terminal blocks on the bottom of the PWM board, strip a quarter inch off both ends of the wire, and connect the wire from the rightmost terminal of the upper terminal block on the breakout board to the downward-facing right terminal of the lowermost terminal pair of the PWM board by unscrewing the terminal screws on the breakout and PWM boards, inserting the ends of the wire into the open terminals, then closing the terminals by re-screwing the terminal screw onto the wire. It may be helpful to bend the stripped ends of the wire to bend them more tightly and orient the wire more directly between the two terminals.
Take a piece of black 18-gauge wire long enough to reach from the 3rd from the left terminal of the lower terminal block on the breakout board to the two down-facing terminal blocks on the bottom of the PWM board, strip a quarter inch off both ends of the wire, and connect the wire from the 3rd from the left terminal of the lower terminal block on the breakout board to the downward-facing left terminal of the lowermost terminal pair of the PWM board by unscrewing the terminal screws on the breakout and PWM boards, inserting the ends of the wire into the open terminals, then closing the terminals by re-screwing the terminal screw onto the wire. It may be helpful to bend the stripped ends of the wire to bend them more tightly and orient the wire more directly between the two terminals.
There should be 6 numbered pairs of black wires. Strip 1/4" from the ends of each wire, and install them into the lower terminals of each of the terminal pairs of the PWM driver board's terminal block, starting with 5 at the top, 4 in the next one down, 3 on the one below that, 2 in the one below that, and 1 in the lowest pair (just above the horizontal pair on the bottom). It may be necessary to trim off a few strands of the ends of the wires to get them to fit in the PWM driver's terminal blocks, but do not cut any more than are necessary as that reduces the amount of current that can be transferred between the PWM driver and the cables.
This completes the assembly of the CEB Controller Box.