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03.05-14.18 Independent Study, Journal – Spring Break
03.05.17 Robot Specs
Today I started going through the parts and testing them. Of course, things are not right.
I didn’t consider that using a motor driver shield would only leave me 5 pins on the Uno. I am aware that I don’t precisely need the shield. However, I feel like it will be easier and more flexible if I upgrade the robot.
DC 12V 6800mAh Super Rechargeable Lithium-ion Battery Portable Pack US Plug
Type: HBJ 12680
Size: 92x60x28 mm, 12V/2800mAh
Output: 12.6 – 10.8 VDC 6800mAh
3-6V DC Motors
AND 12 Volt Motors
SainSmart L293D Motor Drive Shield For Arduino Duemilanove Mega UNO R3 AVR ATMEL
Instructable Link: Control Your Motors with L293D and Arduinohttp://www.instructables.com/id/Control-your-motors-with-L293D-and-Arduino/
Used my cheap acrylic robot platform to make an obstacle avoidance robot and a line follower. It worked. Then the motor burned out on one side and it died. It was very sad.
Tried to rebuild the dead robot but I could not. Went back to the modular design
E-mail from Gene about the LED strips. He says I need a driver but I already have it figured out. I THINK.
Practiced coding “follow me” but I am not sure if it is working. It is kind of buggy. I think I need a servo motor so the robot can track its target better,
Read more about switches. Designed a power system. I don’t feel good about that system.
Hope and I went thrifting. I got a bunch of toys to take apart. I found several nice motors and wheels.
Also, shopped and found new way to join layers
Taking apart the toys was fun and I feel like I learned a lot from it.
Completely revised my robot design. It was imprecise and I was afraid it would not work.
I also designed a prototyping board to go with the robot. I ordered parts to make it. I find that its annoying to have bread boards everywhere. My new system will have them attached and permanently powered. I will also have a voltage regulator so I can select voltage when I want to test parts without worrying so much about damaging them. It will also have an Arduino port so I don’t have to deal with that stupid, stuff cord that it comes with. It is always knocking things over. I may put a built-in LED tester into the top.
I designed a second part for the robot. It will eventually have a disk-like head that holds a servo so it can track things.
I am ready to cut the robot but I have a magnificent headache. I have vomited twice. I need to stop working.
Stayed at the IMRC until 12:30 cutting out robot.
Soldered Arduino mega shield and ruined it.
Ruined usb cord port
Way way too tired, should have gone to bed
I had to redo all my test settings, over and over and over… I wish you could tell the laser exactly how deep to cut, but alas, I do not believe you can. I think you need the CnC for that.
I really don’t need the breadboard mounts. I do need better spacers for the bottom layer.
Went back to the IMRC and put it together!
Stained wood and constructed the robot. I found a BUNCH of errors. I ended up having to drill holes. The support system Hope and I came up with didn’t work so I went back to the plan to use spacers but I cut them out of wood.
Had to go buy stain and more screws. AGAIN.
Worked on power supply system again. E mailed gene for help on how to do the charger. The DC charger only has one port for both charging and powering. Gene said I could use a switch to designate which it is doing without unplugging.
I have worked on the robots every day of spring break. I have had several test robots. Most failed. Some worked but did little of interest due to limited parts. I finally have the first robot that is fully constructed.
The hardest part of all of this has been getting all the components to fit together. That took a very long time. I had to learn a lot and I had to wait on parts over and over… Amazon is my friend.
The plan we made called for two robots. I intended for them to be identical but I feel like that is a waste of resources. My plan is for the second robot to be an “off spring” of the first.
This robot is entirely focused on prototyping. During the learning process, I realized that this was going to be a long journey. I am not going to get bored and forget about it. I will be doing this for a while. I feel the best thing I can do is to create a strong foundation in technology and skills. That is what this robot is trying to do. I designed a system which is expandable and adaptable so that I can use it to design other systems (off spring) and ultimately create my robot army…. I mean ecosystem….
The current robot should have the following features:
It is expandable by stacking new layers and adding additional power sources. The chassis can also be changed without changing the internal layers.
It is adaptable because the components are all screwed down into a grid instead of mounted permanently and the control board uses a screw shield so that parts do not need to be soldered.
The robot behaviors are limited to light and movement. It has space for LEDs in the undercarriage and the surrounding walls (which are not currently attached). I intended to leave space for the addition of sound but I am not sure if I did since I chose not to spend too much time figuring out how to add speakers to the robot. There were too many things to know and I didn’t feel it was something I had time to figure out. If you have input about this, I may be able to incorporate a space for them in the next iteration. I think it is important that I do it eventually.
The robot’s behaviors will include: obstacle avoidance, line following (because it is easy and I have the sensors already), random “search” movement, light seeking and object detection/following. The last behavior is both the most important to me and the most difficult. I hope I can make it work.
- Replace motor mounts. They are problematic. I worry that they are not well aligned and will cause problems in the long term. They are also blocking some of my LED holes.
- Code the basic behaviors, excluding object detection.
- Code object detection which requires incorporation of servo motor to swivel the sensor around.
- Redesign chassis to create enclosure, add functionality and revise errors in the first design.
- Write “user guide” for robot
- Build Offspring Robots
I don’t think I will get all these goals done by the end of the semester but I should be able to at least get the first 3 done.
Thanks for the progress report. I like the modular system design you’re creating. As far as sound goes, you could go with Piezo’s which are high pitched, but take very little power and are wafer thin. The motors themselves will likely make some interesting sound as well.
As far as object detection goes, I’d look at Infrared sensors. I used to work with IR range finding sensors like this:
They’re easy to detect distance and velocity. Tracking is a different story. For that you might want to use light sensors that detect certain light patterns on other robots, etc.
Also, do you have time to meet this Wednesday at noon? We should meet in person and I’m happy to come to you to see your current work.
I tried to mount the wheels. They came without any kind of hardware and nothing I could find at the hardware store fits. I was going to try and cut out a piece with the laser but Wade and Sean said to just use pressure to tighten the bolts, it did not hold.
Wrote up Design revisions
Bottom Layer of Chassis
The motor mount is in the way of the LEDs. I also don’t have enough screws for the mounting system. And I need tiny screws to mount the circuit boards. That could be an issue because I couldn’t even find those screws.
Recessing the washers is a good idea. I should make sure to do that in the redesign, especially if I make an acrylic version since acrylic is slippery.
I picked those skinny black square batteries because they were cheap but they are such an odd size, if I change to a different kind, they won’t fit well. I just ordered 2 extras just in case. That should make things work out fine.
The batteries are 79mm x 79mm and 8mm high
Layer 1 is 3cm high
Battery + platform + battery = 8mm (+2 Spacer) + 6mm + 8mm = 24mm
The motor mount is an issue. It looks messy, but that wouldn’t be enough to change it by itself. The bigger issue is that I feel like the wheel alignment is not precise. I doubt it will be an issue in the short term, but in the long term it will stress the frame. I think I should also make it easier to change the motors. I really need one of those adjustable clamps. I looked at Lowes and they said they only had small ones. I just checked their web site and it looks like we were searching for the wrong thing. They do have them. However, Amazon has some with keys instead of screws. I think that will be easier so I ordered those.
Clamp measurements: 2.5 x 0.5 x 2.5 inches
I really don’t think I need these. I think my original plan works fine. I can just use screw shafts to support the wood. The problem was that I could not find spacers but I solved that buy cutting them out of wood. The bonus is that they look cool and will still look cool if I ever make the design in acrylic.
I can delete the original alignment posts but I think I will keep the location of the screw shafts for now. I could adjust them in the future but I will wait until I am ready to do a total recut of the whole robot.
I love this but it cost a ton to cut it on the laser. I am also concerned that I can’t screw into it well. I may need to revise it to bigger holes. I am going to have to use it a while and see how it works.
The Arduino needs a much bigger cord hole. I thought I measured correctly but I guess not. I had to cut it with a dull rotozip blade. It looks shitty but it’s the best I could do. I might be able to clean it up with a small dremel attachment. In the next iteration, I’ll make that hole better.
The screw posts block my hinge but that can be adjusted. I’ll have to trim the board for now but in the next iteration I’ll just adjust the spacing of the screw posts.
I think this works well but I feel like I should have hinged it on both sides so I can access the second layer completely without unscrewing. I think I can still make it work with permeant power supply. I might put one of my voltage controllers in the front of that layer. I want to use the same power supply as the motors, but I need to be sure I can do that.
Material: electrical components
Converter Type: DC-DC
Input voltage: 5 ~ 23V (better voltage 20V)
Output voltage: 0V ~ 16.5V (continuously adjustable)
For peak current: 3A
Motherboard Size: approx. 50 x 30 x 12 mm (L x W x H)
Display Module: STN LCD
LCD Size: approx. 37.5 x 17.0 mm (L x W)
LCD Accuracy: 1%
Conversion efficiency: 95%
Load regulation (I): <= 0.8%
Voltage regulation (U): <= 0.8%
Idea: I think the final version should have light up walls and maybe even a display screen somewhere. That would be cool.
Tried in vain to mount the damn wheels. It didn’t work and I don’t feel like explaining. Frustrated.