My $50 Robot

[walkercreations]

I know many of you are saying, "Oh no!, not another one of these!" But I just had to share what I'm doing and the progress I'm making on my go at the $50 Robot.

I had put together the initial MCU about a year ago but was going through a very rough relationship breakup at the time and needless to say I made some mistakes on the MCU. I only recently have settled back into my own place and was able to get the MCU out again and look at what I had. As I previously posted, I found some mistakes as well as some missed connections. Most folks suggested I just rebuild the whole thing but something about that just didn't sit right with me for some reason. My thinking was that if its messed up, then whats the loss of trying to fix it? Its a mess, right? So that's what I did. I went back through the schematic step by step and checked everything and corrected what was wrong or missed. I continuity checked it all and everything checks out a-ok. Now all I have to do is apply power and smoke test it. Below are pictures of the MCU. For anyone interested or may have questions, I will try to continuously update this thread. Maybe by this being here will help any beginner that might be interested in making one of these.

A few of the tricks I learned along the way thanks to the help of many users here at the forum:

• Insert a drop of superglue or hotglue where you are going to place a part and then put the part there. It holds it in place when you turn the board over as well as gives you time to visualize everything BEFORE you solder it up.
• When you are following the build and start the MCU, decide which schematic you are going to follow and just use that one. I made the mistake of starting with Admin's Dot Schematic and then switched to Webbot's pdf version and that was where I introduced my first mistakes. I wound up using Webbot's because for me it was easier to follow and made more sense.
• Most importantly, take your time. Rome wasn't built in a day. Relax, slow down, enjoy the experience. Its easier to catch mistakes if you catch them shortly after you make them than if you rush getting it together, then try to find out later what you did wrong

[walkercreations]

I finally worked out how I was going to supply power to my MCU. I am waiting for a Screw Terminal to arrive for the main battery hook up and I will be running a Switchable BEC to the Sensor side for power. Below are two pictures of my smoke test. The system has been hooked up for over an hour and no signs of problems. First picture is showing voltage going to the Sensor side. The multimeter is reading 4.98V. The reason it is reading low is because I didn't have the test hook completely latched to the terminal. All pins down that row have a voltage of 5.00V plus. The small board sitting on top of the test probes is my BEC. The main battery is a 11.1V LiPo 2100 mAh. Second picture is showing voltage going to the Servo side. I have the BEC setup for 6V output and the multimeter is reading 6.06V. Today I hope to get the Chassis finished and the Servo's modified for continuous rotation. Hopefully I can post more pictures tonight or tomorrow.

[walkercreations]

Today I finally got the chassis semi finished. Next step is to mount the MCU on top and then modify the servos for continuous rotation. Below are some pictures of the chassis.











The main wheels are Dubro High Bounce R/C Aircraft wheels and the nose wheel is a caster off an old desk chair that someone was throwing out. The chassis deck is cut out of HDPE.

[VegaObscura]

I love your servo mounts.  Did you make those yourself?

[Kelpy]

Looking good so far 
What servos are you using?

[walkercreations]

The servo mounts I got from Servo City and the Servos are HS 311's.

[Conscripted]

Very nice looking robot you have in the making there. I can't wait to see some finished pictures.

Conscripted

[Soeren]

Hi,

I know many of you are saying, "Oh no!, not another one of these!" But I just had to share what I'm doing and the progress I'm making on my go at the $50 Robot.

Oh no!, not another one of these! 
Please share only cropped pictures - this page is ridiculously heavy, since you filled it with 2MB piccies (and it doesn't show them very large anyway).

[walkercreations]

Not sure what you mean by "cropped" I have them coded in my posting to be reduced from their normal size. Could you explain further? I can always remove them if they are a problem.

[rbtying]

He means that you should a) cut them down or b) resize them in an image editor, so that its actual resolution (and thus file size) will be smaller.  For images displayed at < 1024x768, there's no reason for them to be more than a few hundred kilobytes - two megabytes is much too high a resolution for a web photo.  I will admit, they do look nice that way though =).

[Soeren]

Hi,

[...] two megabytes is much too high a resolution for a web photo.  I will admit, they do look nice that way though =).

Photos doesn't have to be large to look nice.
Here's an example

Original in 4288x2848 pixels (~5MB)

Looks messy due to the auto-cropping of the forum.

Reduced to 600x399 pix (~50kB)

Looks much better, and its size is just 1% of the original!

And further down to 400x266 (~40kB)

As you can see, a wee bit of editing of light and contrast makes this one stand out so much better, even if it's the smallest.

Just measured the larger ones - forum crops to 500 pixels in width, so anything above that is actually detracting from the quality of the photo, as the crop routine is pretty simple (compared to what a photo editor can accomplish).

-> walkercreations
If you're having difficulties with cropping, I can send you a drag and drop program to auto-crop either single photos or entire directories to a common size.

[walkercreations]

I would be interested in the program you are talking about. All I use right now is my Digital Camera and Windows Camera/Scanner Wizard to get the pictures on my hard drive.

[Soeren]

Hi,

I would be interested in the program you are talking about. All I use right now is my Digital Camera and Windows Camera/Scanner Wizard to get the pictures on my hard drive.

Luckily, the program contains the link.
The ingenious thing about this small program is that you just rename it to change the output width.
It doesn't produce as good results as manual editing of course, but it's quick and the quality is not all that bad. Personally, I only use it for producing photos for the web and mostly for when I have loads of already edited photos that just need to be the same size (width), but if you're satisfied with the output, it makes light work of resizing.
It makes the file name of the cropped photo by adding the width to the file name, so the original pic don't get deleted.

I renamed the program to "PhotoResize500.exe" and dragged the original 5MB photo onto it for this (500x332 pix, 18.5kB):

I assume this should be the max size needed here.

(I use the term "to crop" in a loose sense here, as cropping is actually when you cut away some to get a more "close up" photo, but I usually do both cropping and resizing in one session).

[walkercreations]

Thank's for the link to that program. Unfortunately now my posting has been polluted by all the other posts that have nothing to do with my robot or even the $50 robot in general.  Too bad we can't lock threads and control the posts like some other forums.

[Soeren]

Uh oh, just discovered that the newest version, according to the web is more agressive
"Files in the destination folders are always overwritten unless they have the readonly flag set."

[Soeren]

Hi,

Unfortunately now my posting has been polluted by all the other posts that have nothing to do with my robot or even the $50 robot in general.

Polluted seems to me a bit strong word to use here. I thought of removing my posts, but they may be helpful to others (and that's the whole point of a forum, not posting blogs), so perhaps we can get admin to slice it up somehow.

  Too bad we can't lock threads and control the posts like some other forums.

Perhaps you should have inquired for a tutorial log-in instead - a forum is by nature a quite dynamic place and despite what somebody thinks, nobody owns or should own a tread.

[walkercreations]

I agree 100% with you. By polluted I meant they don't really pertain to the robot. I very much appreciate yours and everyone else's input. You are right in that perhaps I should ask for a log in for the other part of the site.

[walkercreations]

Here is a video I made about programming the $50 Robot MCU for the first time. Hopefully someone will find it useful in some way.

Programming the $50 Robot for the first time