system integration

Assignment

• Design and document the system integration for your final project

Added Unexpected Bonus

Downloaded and Used KRITA:

I wanted to be able to use pictures and make a diagram using this pencil tool taht I got. CoPilot suggetsed I use Krita. I double checked with claude since claude knows what I already have. Claude confirmed Krita was a great choice. It seems easier to use at first go than GIMP. I probably should have done a tutorial. It's on the list for after Fab.. on the when time list. I'd love to say that I learned to use I, but I really just limped along usinga ton of layers. That said, my wiring diagram below is done with Krita.

The Individual Work

My asset files are here.

Regulator Lessons

Let's start with - plugging things in is a bit scary for me. I don't have much experience or training with electrity and wiring. So when it comes to plugging anything up.. I really want to have guidance.

In open time, the instructors were helpful with resources for understanding regulators.

This resource provided by Ricardo Marques explains about noise suggesting that a capacitor is put between the voltage source and the regulator.

The voltage regulator works best and will be most efficient when a clean DC signal is fed into it. We don't want any ac noise (ripple) imposed on the DC line voltage. The capacitor, in essence, acts as a bypass capacitor. It shorts the AC signal of the voltage signal (which is noise on the voltage signal) to ground and only the DC portion of the signal goes into the regulator.

Ricardo Marques provided this graphic from teh resource, which suggests a second capacitor after the regulator.

The second capacitor, the 0.1uF ceramic capacitor, is hooked up after the voltage regulator. This capacitor is there again to filter out any noise or high-frequency (ac) signals that may be on the DC voltage line. ...in other applications, such as when outputting voltage to power a logic chip, which needs a precise voltage fed into it in order to give the correct logic output, it is crucial. 

I am wondering if my modules already have some of these capacitors on them.

I was really aiming to understand the physical wiring... show me point A to Point B.. where are these wires connecting? Does it matter if they branch out in a Y before, or meet at the edge of the regulator? Is there best practice.

Rico Kanthatham offer the picture below to help with some wiring and practical knowledge.

Miriam - AKA Ye Eun Miriam Choi shared these two regulators. I was happy to see some more examples of regulator modules.

Adrián Torres provided a picture of a simple surface mount regulator - maybe like the ones he uses on his boards.

I need to do more research to understand, when we use the small SMD adn when to use the module. Since I am a chicken newbie.. I am going to stick with the modules for now since they seem to have the capicitors and other things to make the regulator safe adn work efficiently.

When I got back to the lab, Mr. Dubick aka Tom ordered me a regulator with a big screen on it and potentiometer for adjusting voltage, and some connection clips that allowed me to experiment with the regulators and get comfortable with wiring.

I found the data sheets.

DataSheets: - LM 2596 - big one with screen - MP1584 - small 5V only, no potentiometer

I wired up a regulator using the 12V that I had and the splitters that Tom provided. We discussed making a board with traces for the final use, but using these clips and mocking up the voltages that I was trying to get. He gave me both a voltage amplifier and a I had bought some smaller voltage regulators from Amazon.

I pluged these in and adjusted the voltage down to ~5V using a small screw on the corner of the blue potentiometer. At first, I thought it was broken, but I found a resource (or I may have asked claude - I cant remember _ if I just googled my issue or used my Claude app) that mentioned that sometimes you have to really turn it , maybe even 10-15 times, before the potentiometer will kick in on the first run. It was much less sensitive than the potentiometers that I am used to with the motor drivers.

After getting comfortable with the adjustable big screen regulator, I changed to the small 5V output only regulator that I am planning to use in my project.

Then I hooked up the 2 Amp 9V power supply and confirmed that it didnt matter what the power supply was. As long as it was in range, then it would put out the voltage as adjusted.

After working with the regulator claude and I designed a layout for a splitter regulator board.

Then I designed it in KiCAD and printed it on the Genmitsu. It was the first time I had ever done drill holes on the Genmitsu. I am proud to say that I am getting faster and more confident about milling PCB boards on the Genmitsu at home and the carvera at school, just need to do it a few times successfully to cement the process into the brain.

In order to make this baord, I had to import footprints and create my own footprints in KiCAD. I started using terminal blocks for strain relief and crimped wires with ferrules. However, in the end, the ferrules that I had purchases were too big for the terminal blocks. The lab is ordering some new ones that I will try next week. My motor wires are very small, so we are going to try 26 AWG ferrules. 22 was the smallest in the kit I have.

I had to decide how I was going to mount the terminal blocks. If they were on the top - how would I solder them? On my original board, i put the terminal block on teh backside of the board so the prongs came through the board and I could solder them to the copper on the top. On these boards, because of how I want to mount them, I need to be able to solder on the back. So I made vias and put rivets in them.

I learned to use the Rivet Punch and place the rivets into the board and then line up the punch with the correct die to flatten the rivet to the board. The wrong die was originally in the punch so it pushed the rivet to one side instead of flattening it.

On the back side, the board cracked a bit after punching the rivet, but it was functionally fine.

After getting all the rivets in, I am able to put my regulator splitter board together. I plan to mount this on the underside of the board holder connected to the power jack.

More resources on the DRV8825

I thought I was burning through motor drivers.. and maybe I was.. or maybe I have bad eyesight and I was using a cheap screw driver that came with one pack of the motor drivers. I put on a new one.. changed to a high quality screw driver that I could see what seated into the potentiometer, and now readings are changing. I was able to set my potentiometer up a bit higher closer to 0.3 and then it was able to move the center pill divider and move forward.

In open time, they provided me with more resources for the DRV8825. Here is a link to those resources.

Other Stepper Motors I could use

Another stepper motor that I could have used as suggested in open time was the hobby motor 28BYJ-48. I have played with this one before with the arduino. Here are some resources for that motor. However, on further research, the torque on these motors is the same as my Nema8. I am going to stick with my nema8 and learn how to maximize the torque that I get from it.

Wiring Diagram

I decided that I wanted to lay everything out and make a clear wiring diagram so that I could figure out what kind of wire management I needed and how I would be mounting my board into my physical system. I looked for an open source program that was easy to work in with JPG files. I found Krita.

I used this diagram to lay out everything I would need to fit inside the body of the machine so I could work on how I would route all the wires. I did some modifications to the CAD model of the body to route the LED wires and then started to model how I would mount the board.

My original board would fit, but I hadn't considered how I was going to mount it, so I milled a new improved smaller board.

Then for mounting, I decided to use a springing tension mount using a metal strap. My walls are tapered slightly, so this will help hold the strap in place, but make it easy to take in and out as I figure out the exacts of how everything works together.

I am waiting for 3 straps to come back from the office to make the actual strap, but I mocked it up with paper board. The idea is that the big board sits on top with its terminal facing down to the power board with is mounted with spacers off the bottom. I am hoping to use one screw through both boards, but we will see. If not I will use spacers on both sides, to be able to attach both boards to the strap.

System Flow

I made a flow chart of how the programming weaves into the physical dispenser.