PiTagErrUs

The latest version of NOOBS was downloaded from Raspberrypi.org and copied to two 4Gb microSD cards. Spare Raspberry Pi Zeros were connected to a television, keyboard, and mouse. It was a typical installation which was made easier since the Raspberry Pi Zeros from the taggers wasn't necessary. The beauty of standard hardware was that it wasn't critical to use the exact computers during the install.


USB hubs and cables were run to each Arduino and Raspberry Pi Zero. Each hub had a spot for a keyboard/mouse so it could be accessed in order to start the game or any other game added in the future. The HDMI port was kept open for the same reason. It would be possible to launch games from a serial terminal but that will have to wait for a future iteration.

Programming was written to the Arduinos. This was not a significant task but finding suitable data cables that could pass through the opening was much harder. Many of the micro USB cables in my stock are only power, not data. Some cables were ordered specifically for this project but they were inadvertently power-only cables.


Adding the program to the Raspberry Pi Zeros should have been an easy task but the wrong OS was downloaded for the computers and I didn't want to learn the finer points of running all the necessary commands through a command prompt. An updated GUI OS will have to be put onto the memory cards.

A second tagger was assembled. A pre-wire butt stock and pre-wired forward array were added and all the wires were stripped. Wires to the reload button and trigger were connected and stripped. Everything was run to another control board with an unprogrammed Arduino. This tagger was wired with all the standard color wires.


Sensor modules were added to the sides of the tagger. The holes had to be drilled out since the available screws were too large. This broke one of the traces so that had to be repaired with some scrap wire. The next revision of the sensor boards should accommodate larger screws and the next time these boards are used, the correctly sized screws should be available.


A short video was taken with a probe camera as it was pulled through the inside of the tagger. This doesn't prove anything or serve any purpose other than it was kind of neat to see inside the tagger while it was assembled. The video is approximately forty-one seconds long.


The assembled taggers were placed together for a quick photograph. With two taggers, it will be possible to conduct an actual game with real equipment.  The newly assembled tagger is near the top of the picture.

A standard color code card was made in Google Sheets. This was a simple reference sheet to record which color wire went to each terminal. It was revised from the first edition which didn't have enough spaces for every wire and some other shortcomings. The picture shown below is the most standard arrangement of colors I can make but it will not be used on every tagger.


One tagger was fully wired to the control board. Once the Arduino receives programming and a Raspberry Pi with programming is added, the tagger will be ready for functional testing.

Power was run to the first LED of the string but only the digital signal was transferred around the middle of the barrel. 5V and GND wires were soldered to the other end of the LED strip. This was done as a way to keep the voltage drop to a minimum by feeding power from the back end as well.


The far end power wires were removed since running more wires through the butt stock seemed illogical. Power wires were added around the barrel after all. A wire color code sheet was made for one tagger which contained many of the parts which were not assembled in the standard fashion and "NOT STANDARD" was written across the top as a reminder. The poor arrangement of the color code card and some other shortcomings were also obvious when dealing with such a mismatched tagger.


The most haphazard forward array was placed in this tagger. Many of the wires were run together and all the ground wires were tied together to minimize the number of wires running from one end of the tagger to the control board. Unfortunately, this cannot work since the transistor controlled devices, like the IR emitter, flashlight LEDs, laser and red LED all rely on switching the ground side.

Wires attached to the light rings were too short in most of the cases. This was an error in judgment on my part from moving through the project too fast. The previous wires also had no consideration for color coding, another lapse in judgment.

New wires were cut, this time they were measured against the tagger pipe to ensure they would be long enough. Enough wire was cut so that each tagger could have the same color coding.


Old wires from the light rings were removed with a hot soldering iron. The new wires were attached according to the color code. Light rings only have one terminal for 5V and GND so two wires were attached at each of those terminals. To do this, wires were held next to one another with the copper ends exposed, and they were tinned together so copper bridged between them. Then, the paired wires were soldered to the light ring terminal and there was enough solder present to make a good joint.

Four Raspberry Pi 0s were selected along with four brass spacers. The spacers were meant to add some distance between the PCB holder and the computer. This allows solder joints and other things to pass under it without putting pressure on the board.


Before the computers could be mounted, control boards were attached the PCB holders. These were previously populated with components and Arduinos. Each control board had to be strapped in place with a long zip tie which went through the top of the PCB holder. The Raspberry Pi will be covering this area so the zip tie had to be installed before the computer.


The Raspberry Pis were installed with #4 (3mm) screws which passed through the computer mounting holes, spacers and into the designated holes modeled into the PCB holder. The clearance provided by the spacers was more than enough for the zip tie underneath. The space should also aid in keeping the computer cool since it is open on all sides.

The trigger switch was installed and while wires were being connected, it became apparent that the trigger and controller board would not fit together inside the pipe. Bummer.


Parts from the short tagger were moved to a regular-sized tagger. A different switch plate was used since the new tagger was drilled with a small hole. The print was snug so the switch had to be twisted into place. Perhaps the goal should have been to make the adapter as a threaded nut instead of a plate which could be glued. A screwdriver was used to try to press the switch into place but it was not effective.


The evening was spent creating a wrench (spanner) which could properly install the switch by twisting it. The majority of the device is a long handle with grips while the bottom should surround the switch snugly and allow it to be turned from outside the pipe.


A print of the switch wrench was printed. It was printed on it side so the printer filament strands would reach from the handle to the tool. For a good explanation, watch this video by Christoph Laimer.

A wire from the sensor board was soldered to the output pin for infrared signals. A sensor board was mounted to the tagger with two #2 (M1.5) screws at opposite corners. Each screw hole into the tagger was given a pilot hole. A third hole was drilled for the sensor wire to reach the inside of the tagger.


The board did not sit nicely against the round pipe. Tightening the screws drove the component leads into the pipe but it seemed sturdy. Since the light strips sat high off the pipe, it was difficult to attach them with the adhesive. Perhaps the next model of sensor board should have solder pads which can attach directly to the strips. It would also be possible to model a piece which would act as an adapter for the sensor board and pipe and even provide a ramp for the LED strips.


Wire color codes were recorded for one tagger and the same will need to be done with subsequent taggers. This was necessary since none of them were assembled at the same time or with the same wire color coding. If they had all been assembled at the same time, it would be more logical to have a single color code which spanned across all the taggers.


Sensor boards and light strips were attached to the shortest tagger. This one was assembled as a test to find out what worked well and what worked poorly since the short tagger was the least important. Its size also makes it the most difficult to assemble which would be important to know for future builds.

Six light rings were attached to six butt stocks with twelve small (#2, M1.5) screws from a hardware store. The hole pattern in the light ring wasn't the same across all the rings since they came from different manufacturers so, in some cases, one of the holes had to be drilled into the plastic butt stock.


Short lengths of light strips were cut with five LEDs on each piece. Angled header pins were soldered to the light strips. Half of the strips were given pins on their output side and the other half were given pins on their input side. At a glance, they appeared identical, so a marker was used to differentiate between the two. It was also possible to read the "DO" or "DI" on the strip to tell the difference.

In order to get the header pins into the mounting holes, the pins had to pierce through a layer of adhesive tape on the backside.



Ten sensor modules, which were already assembled, were given light strips on either side so the sensor could fit between them for power. The adhesive on the back of the light strips was kept in place, even during the soldering phase.