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04.05.17 Independent Study, Journal 10
The robot is up and running with a power supply and working motors. I have attempted to upload code but my computer will not read my Arduino. I am working on this.
Note: My computer is having problems that are taking up time. I have had to stop and repair it several times this week. It is going to the shop Monday to see if I can find out what is wrong. If it is not fixable, I will buy another one this week.
04.09.17 Saturday, Update from the Week
I did not post the past few days. I was pretty occupied. I temporarily fixed my computer. Then I worked on code and circuits, mostly circuits. A lot of it was for the LEDs in the Frame for my studio project, but the skill set was directly related to this project to. There was a lot of overlap.
Circuits – I worked on using a 555 Timer to control on RGB strip. There is a ton of information on how to do this. These are just 3 randomly chosen examples.
I thought this was a good idea because I could control my LED strips without an Arduino. Since my Studio project will eventually require several different frames, I thought this could be more cost effective. It is also smaller and I may need the space it safes for some of the frames. I need to be able to control the 3 colors of the strip as well as the overall brightness. Unfortunately, I had no success at all. I understand the theory but I don’t understand how to follow the schematics so I just keep messing up.
Breadboard and Connections – I have discovered that sometimes my designs fail simply because my connections are bad. It explains why things work in test programs but not in the real world. I started planning all this a while ago, but the more I work the more I wish I could stop what I am doing and do this instead, but I am not going to because this is just a matter of convenience, not learning. I have notes written down about how to do it but I am too slow with things like illustrator to take the time to actually build it now. Eventually I am going to build a control box with mounted breadboards, a pair of voltage controllers and a place to mount the Arduino. I will permanently wire the voltage regulators to two power strips so that I don’t have to worry about the power supply coming loose from the board (as has happened several times). I will also put some kind of mounting system beside the breadboards to attach the bigger pieces I need to test like the shields and sensors. I am thinking of using some kind of system to exchange prewired switches and such. We will see how that goes. I will include a mini breadboard as a “pin cushion” to stick wires and components while I am working. I am also trying to use DuPont connectors as often as possible. The cheap jumper wires slip out of place too much. I found that Big transistors are problematic on the breadboard. The long pins seem to get shifted out of place. I stuck one to a DuPont connector and that seems to have helped. I could solder better connectors to the tips but it might make It harder to attach the transistors to an actual PCB board later. I don’t have enough transistors to waste on that. The DuPont connectors are removable so it works for now. I also looked into some different mounts for the ICs. They get bent up too easily. I know none of this is important to either art or my learning process, but it is important to my sanity.
Robot Code – I am still working out the “follow me” code for the robot. The consensus of the dozens of sources I have read is that it is both easy and difficult, making it happen is one thing, making it work consistently is another. I am thinking I might need to use color identification instead of plain distance sensing. I will update this more later
E-mail from Gene on 04.09.17:
Sorry for the delay in reply. I was travelling Tuesday through Friday early morning and am just getting caught up on an avalanche of emails.
You diagram looks great. Don’t attempt to charge and power at the same time as I think you’ll see some issues. Make sure to use a DC switch. Here’s an article that goes over the difference between AC & DC switches: http://www.mouser.com/blog/which-switch-who-cares-if-its-ac-or-dc and another great article on switches: http://www.electronicshub.org/switches/
Based on your design, I’d look for a Double Throw, Double Throw (DPDT) DC switch that can handle whatever amps / load you’re trying to push from your batteries.
If you want to isolate your circuit even further, you could also put a diode inline between the battery switch and your robot components, so that it serves as a one-way gate blocking any voltage that might leak through if your switch malfunctions. Just make sure to get one that can handle the load. Here’s more info on that as well: http://www.mobileinformationlabs.com/how%20to%20guides/diodes/howto-diodes_intro.htm
Also, in regard to your most recent email about wire connectors. Here are some that I’ve used in the past:
and these which can slide together to create long rows and used on breadboards / PCB’s:
The response was not overwhelmingly helpful.
I had previously sent him a picture of a zif socket and asked about that and I asked him about other connectors for shift registers but he sent me info about screw terminals instead. He also gave me some links on switches and DC/AC power but since I was doing that back on April 1, it was kind of too-little too-late. Its good information but not really what I need right now.
I am still struggling with how to figure out amps and voltages. It isn’t the math. I understand the formula. I am just not sure when to use it. What I need is a giant book of word problems. “If you have A & B how much of C do you need.” If I could distill it down to those kinds of questions to learn, I think then I would be able to apply it to my actual work.
I sent this reply to him asking more questions to try and get clarification.
E-mail from me:
I read the articles on DC/AC before. I understand how they are different, at least the theory of the currents. I also understand that they are used for different things and why. The thing that frustrates me is that I ordered switches that have not turned out to be what I thought I ordered.
I am also still struggling with how to figure out amps and voltages. It isn’t the math. I understand the formula. I am just not sure when to use it. What I need is a giant book of word problems. “If you have A & B how much of C do you need.” If I could distill it down to those kinds of questions to learn, I think then I would be able to apply it to my actual work.I have an electronics book that is helping somewhat. I am sure I will eventually figure it out.
I had a PDF on switches but the one you sent is better. It’s easier to follow. I made myself some flash cards on different switches and posted them around the house so that I will remember the vocabulary and visuals better. It all makes ore sense after applying it.
The advice about diodes is good. I recently received a mixed set of them so I can experiment with them. I was reading up on them last night because I finally got all the parts to attempt to make a controller for my LEDs using a 555 timer. I was completely and totally unsuccessful. I read lots of tutorials and I thought I understood how it worked. I think I do understand the theory, but I can’t follow the circuit diagrams. I think I just don’t understand how the schematics work. I guess I’ll add a lesson on that to those word problems. I don’t know if I should pursue it right now or not. I don’t have a lot of time left. I thought it might be a better way to control the LED strips in my frame system, but I think I am going to have to stick with the Arduino. I need to control each color and total brightness with 4 potentiometers. I already designed and built the frame to accommodate that.
I have the screw connectors you referenced. I got those early on when you told me to. I am not sure the barrier terminals will be helpful. I don’t think I understand the purpose. It looks like it would be more trouble rather than less. Connecting wires to screws is kind of a pain. Do I misunderstand?
I was actually asking specifically about the connectors I sent pictures of. I looked them up because when I am making breadboard circuits it is very easy to damage the ICs. They stick in much more securely than other components and the pins get bent up when you pull them out. I thought I’d look for some kind of connector that made it easier to get them on and off.
I hate it when I find that something has not worked because the connections were bad rather than the design. I just recently discovered that it happens fairly often. It explains why something works on 123 Circuits but not on a real breadboard. I read some advice columns about it and made some changes of my own. I soldered better connections to some of the problem parts and switched to Dupont connectors for the wires. I seem to be figuring out when to be alert for it. I really want to make myself a better system if I am going to keep doing this. It will be my next step as soon as the robot is functional.
Thanks for the advice.
04.10.17 Robot Code
I worked on the code for hours yesterday. I messed up a bunch. I ended up just using someone else’s code and adapting it. It still did not work. Then I discovered that the robot isn’t getting enough power to the motors for some reason. I set things up on the little acrylic robot. It looks crappy but this morning I managed to get it working. All it does is avoid obstacles. It does not even have a regular random movement function. I will work on that today.
I sent Gene and E-mail telling him about the problem but he did not respond. I tried to ask him at school but he was super busy.
04.11.17 Gene Responds to E mail from 04.01.17
I hear ya.. It takes a while to get your head wrapped around electricity and circuitry, particularly to feel confident in your decision making. I’ve attached two images that I always fall back on when I want to help folks understand electricity. It’s the pipe analogy and helps get your head wrapped around voltage, amperage, resistance & wattage. These, volt / amp / watts / ohm calculators can also come in handy: http://www.rapidtables.com/calc/electric/watt-volt-amp-calculator.htm That’s where I like simulators like 123D Circuits and LTSpice as they let you test things out and learn the rules without blowing stuff up.
The screw connectors / barrier terminals solder onto a board and then you slip a wire in and tighten it down, similar to how the screw shields work. Keep in mind that some perf boards have different component gaps then bread boards which might be causing your terminal issues. Yes, connectors are key. Once you find some you like, you end up sticking with them, but it depends on how much space you have.
Keep fighting the fight! You’ll get there…
Then he sent me a bunch of documents. Some helped. Some did not. Overall, it did not really do me a lot of good. I feel like I just can’t communicate with Gene effectively. I tried asking direct questions in E mail. I tried talking in person. E-mail takes so long that by the time I get an answer, it is out dated. Plus, most of the answers are not really helpful anyway. When I talk to him in person, I feel like he is always in a hurry and always frustrated with me for taking too long to get to the point (which is true). Then when he does explain things, he gets mad if I interrupt to ask a question but I don’t know what else I can do. If I don’t understand what he is saying, I need to get him to stop and back up. It isn’t as if I am stupid. I just don’t know everything. Sometimes I need to ask and it just annoys him.