Steve's Junk » Programming

Ugluino, the ugly Arduino powered robot

smackaay — Sun, 01 Jan 2012 10:53:24 +0000

So, even though I’ve built a wide variety of crap over the last few years, all of them with varying utility, I’ve decided to build a quick robot. With oodles of free time and the feeling of having to go back to work on the horizon after what feels like an eternity of holiday (1 week) I quickly grabbed a bunch of stuff I had sitting around and put this guy together with all the grace of a kindergarten macaroni art sculpture.

Ugluino Being Built

Based off of an Arduino Nano, this guy works just fine. I don’t like using Arduinos for the following reasons.

Perceived lack of control of what’s going on inside
Feels like cheating since it’s so easy
Arduino UI is kind of shitty, especially for larger source files.
When dealing with AI routines, making it difficult to use multiple files is a minus

Anyways, i plugged ahead and quickly pounded this out with the following IO

Input – The only one, the Echo pin on the ultrasonic sensor
Output – Trigger on ultrasonic sensor
4 Digital output – for controlling direction on SN754410 Quad half h-bridge driver. These go to two gear motors which are attached directly to wheels
1 PWM out for duty on motors
1 attached servo out of the servo to turn the sensor

The back end of the Ugluino

Most everything worked out swimmingly until I fucked around with some wiring and produced a short. I hooked the robot on to the USB supply on my computer, I noticed after a few second that the power to the unit wasn’t running… hmmm POOF! Well, as it turned out, there was a problem with the wiring to the ultrasonic dealy and it blew what I beleive was a zener diode

I wasn’t able to figure out exactly what it was, I suspect that it is a zener diode that selects between main power and USB since it is on the output of the VReg. I could be wrong. Since I didn’t have any more Arduino Nano’s I simply tried to fix it and soldered a wire across the offending gap. The device seems to work fine…? Anyways, if anyone know what that part was on the Arduino Nano v3.0, I’d like to know ’cause I couldn’t find the 3.0 Schematics and the design has moved those parts around.

Anyways, The robot moves around based on a very simple algorithm.

Stop Moving
Scan from 40Deg Right to 40 Deg Left in 10 deg increments
return appropriate movement from a function that analyses it
execute proper movement (Forward, Backward, Right, Left, Hard Right and Hard Left)
rinse
repeat

It seemed to work reasonably well. I’d like to build a more sturdy version for shits and giggles so that I can play with the algorithms. I’m probably gonna build one with a PIC18F2685 instead of an Arduino. Also, instead of a single sensor, I will use IR proximity sensors to detect low lying objects. Moving the sensor with the Servo make the robot seem more intelligent than it actually is like it’s ‘looking around’. I quite like that.

Anyways, it’s my first post of the year, considering it’s January 1st and 3:52 am as I write this. maybe I should go to bed. Here’s a video of it getting around.

Some neat devices for the hobbyist

smackaay — Fri, 30 Dec 2011 05:55:27 +0000

Ok, well, the year is coming to an end and I’ve seen a number of neat devices out there but here are some that I own. The next year coming up is a going to be an interesting year methinks especially since there’s gonna be some big changes in my life, not to mention the fact that I’ve quit smoking for some time now.

Anyways, here they are:

Arduino NANO

Arduino NANO

This nifty little device is the Arduino NANO. Now, me being me I believe that the arduino’s are something akin to cheating since you don’t need a programmer, it runs right off USB and communicated directly with the computer. The small size of this device and the ease of use make it truly a neat device. Call me lewis ’cause I am starting to like the arduinos. They sell for as little as $14 on EBay (they are probably knockoff but work fine) and are strangely useful for bashing out simple stuff.

Mini PIR Unit

PIR Sensor

This little guy can detect motion (heat difference) up to 5M away. it only draws .15mA and costs only about $4 on Ebay. The interface is simple with two trim pots, one to set the sensitivity and one to set how long the signal stays high when triggered. I bought a whole bunch of these for a project I never finished (A distributed monitoring system) and I might make something cool out of them.

2.4Ghz Transceiver

2.4GHZ transciever

This little guy seems to work really well. Based off the nRF24L01 chip, this transceiver will draw about 15mA at continuous load. If you’re using it intermittently, it’ll run at about 2mA. Alos, it was really hard to get an image of the pinout for this device since the seller kept saying they’d give it to me and never did. Here’s an image of the pinout.

transceiver pinout ripped from somewhere I don't remember (sorry)

You can get these devices for about $4-5 each. A real steal.

CP2102 USB to Serial out

CP2102 USB to IO

These guys are useful because you can plug a test device directly on to the usb port and not need a max232 or equivalent. It features a 3.3 and 5v port and works like a damn. Concievably you could use this with an intermediary to provide the SPI interface to the 2.4GHz Transceiver and use it to provide communication to other transceivers to the computer.

UltraSonic Transducer

Ultrasonic Transducer

This is the ultrasonic transducer. I was playing with it last night and it works really well. It measures anywhere from about 1 inch to 16 feet or so. Simply provide a short 10 to 100 us pulse to ‘trig’ and measure how long the ‘echo’ pin remains high. the ‘echo’ pin will go high after a delay once the trigger pin has been pulsed. I was able to get pretty good accuracy once I calibrated it and with some averaging routines I was abble to get resolutions of about .01″. Surely it wasn’t THAT accurate but it was close. These again were only like $6 each. It should be said, that with full measuring duty this device draws about 15mA.

Anyways, that’s what I’ve been playing with. Hopefully other people may purchase these little trinkets and have fun. EBay sure is an awesome place for the hobbyist like myself for weird knick-knacks!

Stuff I’m playing with

smackaay — Sat, 24 Sep 2011 22:18:06 +0000

Well, since I posted a bit of stuff yesterday I’m gonna post a couple of other things I’ve been playing with. Since I finally have a day off. may as well.

The FPS I’m making

I don’t know what I’m gonna call it, I don’t even like FPS’s anymore. I dunno. Anyways, heres a screenshot

FPS a la' Steve

Nothing spectacular.

Arduino and ChipKit

Like I mentioned yesterday, I’ve been playin with both the Arduino and ChipKit. Frankly, I need to get over my personal bias over these arduino based things. The way I feel about them is that it’s like cheating, where very little learning is required to make some sort of result.

I am however wrong. With the progress of technology we use technologies that are based off of previous technologies. Even using MCU’s would technically be cheating by my reckoning since we should be using a CPU and related chips. Then even deeper we should be using nothing but transistors in order to not cheat. So, by that reason, I am wrong. Using an arduino and premade shields shouldn’t reduce the feeling of accomplishment at all. Now that we don’t have to worry as much about hardware, application becomes top dog.

Anyways, Here are the Arduino and ChipKit

ChipKit and Arduino

Now, as it might seem, the chipkit is quite a bit more advanced. It uses the same arduino software for compilation. It is also substantially faster. There was a comparison done, here on hackaday. It is a really neat device despite the fact that the software isn’t optimized.

The only problem though, as I have already mentioned is the voltage difference. So, it can be said that many shields would not be compatible with the chipkit. They do have similar layouts though.

ChipKit and Arduino from the top

A problem I did have with the chipkit was that the software wouldn’t write to the chip. apparently I had to download and burn the new bootloader to the MCU that was on board. lucky thing I have a pickit3 and was able to burn it, otherwise it would’ve been a brick. I think it’s odd that they didn’t test for that (apparently it was a certain batch of pic32 mcus that had a problem)

Something I do like about the chipkit is the extra IO and the fact that it uses a miniB plug rather than a massive printer usb plug.

Wireless units

At 4$ shipped per piece, these are wireless units. they have a variable frequency selectable by software and have a range of about 100m. I was going to make some of the centerpieces with them but since people take them home, it’d be pointless.

Wireless modules

Well, I’ll keep on truckin’

Happy 2011! uuh, I guess a bit late though.

smackaay — Thu, 03 Mar 2011 18:10:02 +0000

It’s been well over two months since I last posted. Frankly, not a lot has happened in the meantime anyways. Work is going well and life is pretty good. That said, I’ve begun to regain my inspiration for electronics again and I’ve been going hog wild building stuff in the evenings. Just some stuff to touch on I guess…

My Lab

Well, again I have a secluded labratory in the shop I work at. It consists of 2 desks, two shelves and all of my equipment. It’s nice to hang around and listen to music and stuff while having access to all of the manufacturing facilities I could ask for!

Here’s a picture of my lab as I was setting it up.

The new lab as of 2011, this is an early picture. there is more equipment, parts and shelves now

It’s a real treat here and I’ve been sitting up here for many hours on my projects lately. Yay!

A veroboard planner PDF

Not really a project per say, however, somebody might want it. It’s for printed pcbs from PCBIran which have a ground loop on the outside and sets of rows and columns. Somebody may find it useful. I dunno.

BOARD PLANNER 01

The Shop

The shop I’m at is investing in new technology (IE. CNC mill and CNC Ram EDM) and I figured it’d be neat to take an overview picture. Sure is crowded though. The mill, as was stated earlier, is a Haas VF-5 with a 40 taper and the Machine is a large CHMER EDM, more on that thing later in the post

The shop I work at is growing, but not in floor space.

It’s actually much tidier now, this is when we were installing the EDM.

Rotary Table and CHMER EDM

I am developing a rotary table interface for the CHMER Ram EDM. The fools at CHMER decided that the machine requires NO extra M-codes for interfacing to external hardware… WHY!!!??!?

So now I have to monitor the outrush current of the pump, turn it on and off a prescribed number of times and then the rotary table can index. I’m still kind of in shock that nobody has ever presented CHMER with this problem. Weird!

The TI Launchpad

I have just ordered the TI launchpad for $4.60 or whatever it cost. TI is attempting to break into the hobbyist market something fierce. unfortunately, after looking at the development tools available, they are all way overpriced.

While they do provide a code-size limited version, which is useful for most things, I think people like to have unfettered access to their chips and what kind they use from a particular vendor. When the development tools that allow this are in the $500 range, that’s simply too much.

Perhaps there will be some good 3rd party support like Atmel and Microchip has and they can really take their MCU’s to the next level. It’d be very cool.

The Rest

Well, there is probably still more to say after such a long hiatus but I can’t think of it now. I do have some other ideas banging around in my head like a new design of the coolant refractometer which won’t foul. A robot that is machined beautifully and function on sonar. And a new coolant nozzle design that will kick Spider Cool’s ass from here to main street (I’m actually pretty stoked about this one).

The new Haas Mill Features

smackaay — Wed, 22 Dec 2010 17:36:20 +0000

The company I work for has recently purchased a Haas VF-5 40 taper machine to augment the capabilities of the shop. Seeing as they didn’t have one before, this will greatly improve the capabilities of the shop.

The item of interest to me is the fact that it’s brand new and Haas has made a number of changes to their CNC mill line. Aside from their new higher contrast 2-tone paint job and sharper featured shrouding, here are some interesting changes that they’ve made. This may not be new to some people but if you haven’t used a haas made in the last 4 years or so, this may be of interest.

The Control

The new haas control

Nothing amazing about this control aside from the fact that the screen has a lot more info packed on the screen. Selecting one of the screen buttons toggles between the panels rather than actually displaying a different screen. None of the buttons have changed their functionality otherwise. I do find the screen switchovers to be a bit laggy and difficult to read at a distance but it is otherwise OK. Also Probong has a much more integrated setup than in previous versions whereby you can offset tooling from the tooling screen.

The Jog Pendant

The Haas Jog Pendant now has an LCD screen and greater functionality

Like the image says, the pendant now has an LCD screen. It also features two sets of dials and a toggle lever for axis slelection rather than the rotary switch allowing you to use it without looking too much at the labels.

The larger dial on the face is an analog dial that allows jogging at various speeds and goes about a quater turn left and right that springs back. the smaller one serves the original purpose of increment jogging. Increments are chosen on the screen rather than on a dial.

Also, things like current program, offsets, and various other minutia can be displayed.

The Screen on the Haas Pendant

There are is a problem though. That being the noticable lag from the pulse encoder to motion occuring on the machine. Often times when you want to move there is a considerable time difference from when you turn either the analog wheel or the pulse encoder. Also when you use the pulse encoder at a high rate, it skips many of the ticks or gets “jumpy”. the motion is not smooth.

Overall though the functionality is greatly enhanced.

The rest of the machine

Here are some of the other changes I’ve noticed.

Quieter Spindle
Different Coolant arrangement
Different design on the programmable coolant
Larger casting
Side window locks
an additional set of shelves on the side with a light
Power saving settings
Different Shrouding and duo-tone paint.
Removal of coolant tray around table
Shrouding around chip spigot
Raised handlebars for moving coolant tray

There are probably more changes than are what is listed here. Here are some pictures of the machine

Long time no post. Machining and trying to get back on my feet.

smackaay — Mon, 08 Feb 2010 07:57:19 +0000

Well, it has been some time since I posted, about a month and a half or so. There have a been a number of events that have occurred in that time that have both beneficial yet disappointing. I’m not really sure where things are going right now but I hope they get better.

Anyways, on to some things I’ve been working on.

Machining
While I am a decent machinist, it is a job that I vowed to myself I would never do again. Lo and behold, I am machining again in order to get some funds and to simply make it through the months in terms of rent and bills. Some of my previous stuff has left me bone dry in terms of money. Realistically, I should thank my lucky stars that I have a skill I can fall back on that pays well and is relatively easy, most others are not so lucky.

Luckily, the shop I’m working at is pretty decent, though I’m not the machinist I once was and my machining style doesn’t really match the pace and style of the jobber shop I’m working at. Hopefully I either get better soon or find something more along the lines of what I’ve become good at.

Stamping machine with the Haas mill
This is a little project that I came up with after thinking about dot-peen machines. Basically the idea is to take a Haas mill and allow full control of its machinery to turn it in to a makeshift dot-peen marking machine.
This feat is accomplished through the serial port with a pass-through interpreter box connected to a computer.

Here is how it is all achieved.

First Step: Computer -

This is where the points and fonts are generated and created. All of the end points are sent out from the computer at a lower baud rate than the mill uses. This allows for longer cable length on the RS-232. Of course I could use USB or RS-485 but RS-232 is more common an interface. A sample output might be:

MOVE X.455 Y1. (Basically a rapid move)
STMP X.461 Y1. (Stamp here)
STMP X.467 Y1. (Stamp here)
HOME (Go back home)

The communication is full duplex between the pass-through and computer so that the pass-through can request more data.

Second Step: Pass Through -

Despite its name, it does not actually pass data through. It interprets the data and controls the stamping head. It will interpret the data and send the machine the appropriate G-codes to perform the commands. The pass through will communicate with the machine at 115200bps whereas the computer <-> passthrough is about 9600bps. a sample output might look like this (based on the above text):

G00 X.455 Y1.;
G01 X.461 Y1. F200.; (move to stamp position)
DPRNT [S]; (Is at position, passthrough will stamp)
G01 X.467 Y1. F200.; (move to stamp position)
DPRNT [S]; (Is at position, passthrough will stamp)
G28 G91 Z0;
G28 G91 Y0;

Third Step: Stamping head -

Not really a step so much as device to peen the surface of the part. Here is a picture of an earlier design I made for a stamping head.

I don’t know if I’ll ever do this one. Macros need to be enabled in order for this to work so a lot of machines won’t be able to take advantage of it. Also, my time is limited.

Programming a CAM system

Since the shop I’m at has no CAM system for the guys on the floor and I don’t want to use a cracked copy of say, Gibbs or MasterCAM. I’m writing my own. The going is slow but I am slowly developing a little 2.5D cam system. The math function are working and the object creation is starting to come on line. Now for an interface. I am thinking of migrating over the VB.NET for this program since it does have a lot of nice object handling functions and it is a little easier than creating a user interface from scratch.

Anyways, That’s what I’ve been up to for the last while. Hopefully I get a car soon so that I don’t have to walk in this anymore.

This was taken on my walk home the other day.

Grams to Krebs conversion formulae

smackaay — Tue, 10 Nov 2009 21:02:39 +0000

After many a day scratching my head as to why I can’t get my viscometer to calibrate correctly, even assuming logarithmic and quadratic relationships, I find out why I have been having so many problems.

Krebs units are in not very linear!

I have found an old chart with lots of grams to krebs conversions on it and after painstakingly transcribing them, I have come up with the following graph.

Grams to Krebs (grams on horizontal axis, krebs vertical)

As you can see, there are a number of points of inflection along this graph. Here are some images of the various best fit scenarios regarding this set of points. These points encompass the KU values 40.1 to 141, just for reference.

Linear (0.0813637)*x+(64.5289)

Quadratic (-0.0000813007)*x^2+(0.173302)*x+(46.274)

Cubic (1.01193e-7)*x^3+(-0.000252971)*x^2+(0.253045)*x+(37.7895)

Quartic (-2.3958e-10)*x^4+(6.42986e-7)*x^3+(-0.000653817)*x^2+(0.359922)*x+(30.3868)

Quintic (1.93677e-13)*x^5+(-7.87171e-10)*x^4+(1.20087e-6)*x^3+(-0.0008998)*x^2+(0.403747)*x+(28.1763)

As you can see, a quartic relationship is quite passable though I still added a quintic relationship. It may be possible to make a simpler equation based on these values but I thought it prudent to stick to what I know.

You can see the dataset here. GramsvsKrebs.txt

Be warned, I may have made mistakes or the chart may have been wrong, Do your own research if you want to be certain of your results. Hopefully this is of help to somebody.

Working on new viscometer head

smackaay — Tue, 06 Oct 2009 18:40:50 +0000

Well, I’ve been designing some new stuff since having a little wind of inspiration. This head weighs in at about 700g and provisions have been made to allow an attachment to a handle and therefore a hand-held version could be made. Here are some images.

Line Drawing

Fully Assembled visc head

Viscometer head opened

Viscometer head from the back

I’m going to use these design concepts on the next in-process version. I’m going to design the external case for the electrical portion and for possible battery storage. Since the motor only draws 100ma at 24v or 200ma with a 12v motor, a hand held version is definitely possible. This version will use a PIC16F767 for control and using a smaller LCD display to display info.
Now, on to developing some other devices. I’ve wasted far too much time in the last many months, time to get busy.

Getting closer to final completion

smackaay — Wed, 23 Sep 2009 02:11:19 +0000

A long road behind and still some ahead, here are some pic of the viscometer in its state of completion.

stormer viscometer with cover looking in

viscometer from the back

viscometer standing up

viscometer laying down

stormer viscometer with cover

Now to implement the ModBUS protocol and finish up this project.

In-Process Stormer Viscometer – Damn near complete

smackaay — Tue, 25 Aug 2009 01:27:49 +0000

The viscometer is nearing full completion! YAY! To mark this occasion to mark the end of a long two years, I am placing a small gallery of the almost finished product. The only thing missing is the outside cover which consists of a 4″ od aluminum tube. Also, the springs I’ve ordered have also not arrived as yet, however, for now, the elastics will suffice. Here are some of the features and facts:

Can be used in-lab or in-process
Selectable RPM with a tight tolerance on RPM +/-0.5RPM
User calibration routines. This allows the end user to calibrate with 3 fluids of known viscosity
16 key keypad, used for calibration and settings, also for running special tests
Can be used as a laboratory gel-timer
Can be used for custom tests besides stormer viscometry
Low power consumption <100ma or <2.4W
RS-485 Serial output
Control electronics have complete galvanic isolation
24VDC supply required
repeatability (requires further testing) +/- 1.5%
Modbus protocol (not yet implemented)

Programming, Drafting, Designing and whatever else…

smackaay — Sat, 25 Jul 2009 22:38:56 +0000

Well, it’s been a busy few weeks since I left the business training program. Thankfully I have some work lined up and things may go well for the short-term. For the last while I was working on the design for a plastic enclosure for a customer. Everything went quite well and the customer is an absolute joy to work for/with. Based on a board and taking cues from other ideas, I drafted a simple enclosure for a device. Here are some pictures of the enclosure.

Worked out well…

Also, I am now continuing my foray into the automation stormer viscometer as well as my auditory camera level. Things should go quite well if I bust my ass…

Chaos game, a little program.

smackaay — Fri, 22 May 2009 04:09:09 +0000

Was bored for a little while today so I made a quick program in Freebasic to produce a Sierpinski Triangle and a some sort of pentagonal fractal. This little program uses the chaos game method to produce it.

seirpinski triangle

seirpinski at 5

I think the result is kind of interesting, I’ll post the crummy little program.
choppy.bas
Nothing special with this, just the result of boredom. You could change the radius and the ox and oy variables to look deeper into the triangle/pentagon.