Thursday, October 9, 2014

anibit.com is down

[UPDATE: we're back in business!]


Should Anibit ever go down again, https://twitter.com/AnibitTech is probably the best way for emergency communications. Alternatively, you may send an email to: anibit.technology[at]gmail[dot]com, but note that that is not a primary address I use, some of the spam bait anibit public email addresses alias to that to let gmail's superb spam hammer sort out the cruft.


--P

Wednesday, October 8, 2014

I jumped from a plane last week....

....figuratively speaking, of course. (I'm not crazy! Well maybe a little)

Last week, I ended my employment at my "day job", to work full time on Anibit.com and building a consulting business. It's very exciting, and I'll admit, a little scary. I'm going to be adding a lot of services to Anibit.com (and I'll add a "hire me" sidebar pane to this blog soon).

It's been a dream of mine to run my own company for a long time. I'm not getting any younger, and I plan to die with no regret for something I never got around to. The timing for me personally is as close to perfect as it gets, which is to say not really perfect, but pretty good.

I've also always wanted to do pod-casting and video production. I've started a daily podcast, but I'm in "practice mode" right now, because I need to work on my "radio voice"(I say 'um' in between every other sentence). I've also played around with producing some screencast tutorials, also not ready for prime time. I'm also now in "fail fast" mode on  Kickstarter project that I've been cultivating for 6 months in what little free time I had. I'll go public with those details soon.

Wish me luck in these exciting times, expect to see more frequent updates here, and on Anibit's website. And if you have any Windows desktop, Android, or AVR/ARM cotrex applications you would like developed, give me a shout at anibit.technology[at symbol]gmail[dot symbol]com

--P




Monday, September 29, 2014

Protip: max safe AVR clock speeds at 3.3 volts.

One thing I love about AVR chips is how electrically hardy they are compared to most ARM devices. Most can run at 5 volts, and source tens of milliamps. Most also run well at 3.3 volts, which is especially good when interfacing with an ARM.

One thing to watch out for is that the maximum stable clock speed for an AVR is reduced when running at lower voltages. ATtiny85s cannot run reliably at the internal pll'ed clock speed of 16MHz, when powered at 3.3 volts. I've cried myself to sleep over this, so I offer this cautionary tale. Read your datasheets!

--P

Tuesday, September 23, 2014

Domain woes.

I'm having some issues with my new domain for this blog, so I've temporarily reverted it to the old bytecruft.blogspot.com domain. Atom feeds may or may not be working and please disregard any wierd redirect warnings ove rthe next few days while I work it out.

--P

Working remotely on a Raspberry Pi

I've been trying to do some real work on a Raspberry Pi and it's cramped my style a little bit to cannibalize a monitor and slap an extra keyboard an mouse on my desk.

Working in Raspian Wheezy, you have a lot of Debian Linux at your disposal, so I thought, "I'll just ssh in" That works great, from either a Linux VM, or using Putty on Windows. I needed to run graphical applications and spawn terminals at will, so I really wanted full desktop experience.

X11, the base graphic interface run by virtually all Unix-like operating systems, supports a feature known as display redirection. I used this back in the 90's when I tried to make use of a boat anchor DECstation from my Slackware Linux box. It still pretty much works the same way it did 20 years ago. Before I get too far into how it works, I'm just going to stop and and mention that if all you want is to remotely run graphical programs on your Rasberry Pi, stop right there!  There is a much easier way! X11's server-client model is very powerful and flexible, and is unique in a class of technologies that has stood the test of time, but it's not very "get'er done" user friendly.

Linux machines support Microsoft's "Remote Desktop" protocol with two programs: xrdp and rdesktop.

xrdp is the "Remote Server". This runs on the machine that your want to remotely log into. Note that is this backward from X11, where the "server" is the machine with the physical display, and the client is the (remote) application that generates contents to display.

To install xrdp on your Pi (if using Raspian or other Debian Linux derivative), type:

sudo apt-get update

then

sudo apt-get install xrdp

You're pal apt will download, setup, and launch the xrdp deamon to start listing for connection requests. If you're parnoid, reboot your Pi to make sure.

Tuesday, August 26, 2014

RAM disks and page files.

I've run across some bad information on the Internet more than a few times lately, and it prompted me to try to counter this misinformation about optimizing workstation computers with gobs of RAM.

The tl;dr version is: leave your RAM alone, let the operating system manage it. Teams of people smarter than you and I have figured this problem out.

The Problem:


The advice is basically that emulating a hard-drive/ssd with system RAM will speed up your system, and that moving your paging file to the RAM Disk can improve system performance. That is just wrong. Why does this idea never seem to die the death it deserves? I think there is a lot of misunderstanding of what a page file is. There seems to be this idea that the reason a PC is running slow is because it's spending too much time writing to the paging file. 

How paging files work.


All modern desktop operating systems support the idea of a paging file. In short, a page file is the operating system's way allowing programs to ask for more RAM than what actually exists. In the old days, when RAM was used up, the operating system simply returned an error when a program asked for more memory. The purpose of a page file is not to speed up a computer, it is to allow your drivers and applications to have access to more memory than is actually available on the system. Indirectly, a paging scheme can make available more RAM for other uses, which does lead to high performance. 

Mental experiment: a femto computer:

Monday, August 18, 2014

New Domain

I'm trying out Google's new Domain service. It seems Blogger is a little paranoid and throws up a ton of "redirect" warnings. I'm hoping that The Goog figures out that both services are their own, and it's the same person linking this blog to www.bytecruft.com. Either that, or I've got something horribly configured.

I swear by Oden, I shall return to this blog in full strength.

In the mean time, enjoy the fruits of my recent tinkering with Javascript. I'm certain that I probably made a lot of js faux pas, but hey, it's Javascript, the business casual programming language. I want to build a lot of "nano" tools or interactive demos, and using the browser is the best way to get the widest reach. Once I get a little more of a command of it, I think I'll switch to something like TypeScript or Dart.

I'm pretty sure that you'll run into issues if you use anything but the latest browsers, I didn't do any testing of old browsers, and probably will always target the latest stable browsers.

I wrote a calculator tool for determining the target address for an AVR microcontroller relative jump instruction. The motivation was personal, I've spent a lot of time recently staring at hex dumps from AtTiny devices, I wrote a bootloader (more on that in a future post), and debugging it involved memory dumps of a lot of dynamically generated rjmp instructions. (AtTiny device do not have hardware support for bootloaders, so you have to fake it in software). I got tired of calculating it by hand, so I wrote a spreadsheet, and thought, "If I could write it in a web app, it would be there forever, and I'd always have access to it".

Check it out at:

https://anibit.com/webtools/small/rjmp_calculator/

--P



Friday, May 16, 2014

List of Software for Makers

I've wanted to make a list of software list this forever, for this blog. I ended up creating one on the Anibit Wiki, since I'm on a drive to jumpstart it with some quality content.

--P

Thursday, May 8, 2014

FMUL

As the French like to say Crikeys! It's been a long time since I posted. I thought once Anibit.com went live, I've be able to post to ByteCruft mroe often. That was the plan, at least.

I've been pretty much head-down, working on things related to Anibit. I think some more of it will be public soon.

So the title of this post, is my Public Service Announcement about ATtinys. FMUL is Atmel's assembly instruction for "unsigned fractional multiply". Before you make grandiose plans that hinge on doing fast math in hardware, make sure your CPU supports it. Most, if not all, ATtinys do not support hardware multiplication.


--P

Thursday, March 13, 2014

Updates.

Whew. I've been spending alot of time on my "Sister site". I thought I would have had more time to blog about Fun StuffTM by now. There is so much work behind the scenes that you need to do to launch a site like I want to do. I enjoy it, the supporting work, but it's all still more of the means to an end, I'm enjoying the journey, but I'm looking forward to the destination.

I have to say one stark lesson I've already learned is "Just because you've built it, doesn't mean they'll come". I have very little traffic to my site, and website traffic generation ranks substantially below marketing in requisite business development activities as far as my interests go. I know there are thousands or tens of thousands of people out there that would be interested in the site, but how do I connect with them? Part of building a catalog of existing parts was to attract a regular audience/demographic interested in hobby electronics. That, and other content I have planned (in the next phase, starting soon) would make Anibit bookmark/Feedly-subscription-worthy site.

But I get the feeling, given metrics to date, that there's more needed that just throwing content up and hoping for people to find it. Yet, I don't know what that thing is. My traffic to Anibit so far is dismal, especially if you cull the traffic generated by my personal Social Networking friends(lot of my hits cluster in places I or my family have lived). I supposed I should keep it in perspective (starting a business requires a healthy does of that). Self-bootstrapping with cash on hand like I am doing requires a lot of patience, and the experiences I've had while doing it so far have almost all been rewarding and overwhelmingly positive.

--P

Tuesday, February 25, 2014

Smart Reflow Oven

I generally don't just post links on Bytecruft, but this is beautiful.

This is a reflow oven controller:

http://hackaday.com/2014/02/22/smart-reflow-oven-is-over-engineered/

My oven controller is coming along, in between doing a lot of behind the scenes work on Anibit.com.

--P

Monday, February 3, 2014

Reflow oven

I started a new project recently, a reflow oven. This time, I've started with the physical build, and the software side of it will lag behind. I've laser cut the case I designed in OpenSCAD, and I couldn't be more pleased with the results.

The case with the "human interface" components - a touch screen LCD a 1 watt speaker.

I have some projects in R&D for Anibit, and I'm going to need to whip up some PCB's. I need a reflow oven, and I'm going to recycle an old toaster-over. I was inspired by this project, which was in turn based on osPID. The touch-screen was something I've had lying around, waiting for a project. 

Sunday, January 19, 2014

Introducing Anibit

I started this blog in part to document my hobby work, and hopefully provide ideas or inspiration to others.

A lot of work that I've done lately has been on something I wasn't ready to blog about... until now.

I'm starting a new website, devoted to hobby electronics and programming, and hope for it to become more than just a website, I'd like to use it to be a more substantial presence, and a greater contributor to the community, by publishing code, tutorials, and designs, as well as hosting forums and of course, I'd love to make my hobby, self funding, so it will feature a store, where I'll sell my original products, as well as resell other product of interest to the makers and programmers out there.

Without further delay:

Anibit Technology:
https://anibit.com

Like on Facebook:
https://www.facebook.com/anibittechnology

Or, if you're more of a pluser:
https://plus.google.com/+Anibit/posts

I plan to release most, if not all, of the code for the work I do on Github at:
https://github.com/anibit



Sunday, December 22, 2013

Traffic Light

[Editor's note. This is a post that I started almost 3 years ago, I'm making an effort to purge or polish some of the unfinished or unworthy posts on Bytecruft]

This is a traffic light I made for my kids. It's got a ATtiny 13 driving the leds. It also features a "soft" on-off circuit   driven by a tactile momentary push button.

I know, another AVR LED based project. They're so easy. I swear, I work on more than LEDS and with chips other than AVR's. It's just that the AVR ones tend to get 100% finished. Part of my hopes for this blog is to provide motivation to finish a couple of the unfinished projects I have. Actually, looking back, it's not so much a problem of motivation, but time. I usually "multithread" my projects, work on several at once, to keep form getting burned out or over-obsessed with one. Sometimes, before I know it, a project hasn't been touched in a couple months.

This is a project I did for my kids, it was another one of those "in between" projects, where my goal was to make a small project that would be lightweight after working on something big.

Present-day action shot, I finally replaced the 3+ year old batteries
during the teardown/photo shoot for this.

The real neat trick with this project, in my opinion, was the power management.

Sunday, December 1, 2013

Eggbot hack

I was preparing today for an upcoming Eggbot demonstration, when I noticed a lot of play in the pen arm.


This wooden piece had a lot of play because it had
loosened from the bushing it was glued to.

Monday, November 18, 2013

Not Dead Yet.

I slept funny recently, and apparently cut off circulation to this ByteCruft.

It's not dead, I've been occupied with family, and several projects I'm not ready to reveal yet (which make it hard to blog about).

In the mean time, enjoy this nerd humor:

--P

Thursday, September 12, 2013

Complexity. Ambition. Progress.

What is the inclination many of us have to take on more than we can handle?

I have a really cool project I've been working on, that I'm not quite ready to reveal. It's turned out to be more ambitious that I originally thought, although I am making decent progress and achieving some things I doubted would be possible.

Is it that we overestimate our abilities, our speed, or that we have an inherent desire to avoid underachieving by aiming too low? My gut says.... well never mind what my gut says, it's always hungry, and rarely expresses anything appropriate for mixed company. My head says that we're simply just poor estimators, and there's probably tons of blogs and expert on the web that agree. What has really consumed a lot of the time on this project, were some of the mundane things that I didn't really consider, such as spending a week tracking down errors due improper CPU registers.

It seems that as some of my home hobby projects get more ambitious, and by definition more cool, I'm spending longer and long in between completed projects, with more time spent in the "this is going to be magical one day" phase. I definitely think after my current project I need a few short and sweet ones, to get that gratification of having achieved magic.

--P

Wednesday, September 4, 2013

Really short sanity check list for vexing AVR anomalies.

I've been chasing down some bizarre behavior on an Atmega 1284 for the better part of a week.

I'm posting this so that I can print it out and tape it to my forehead for future reference.

When trying to determine the root cause of strange behavior in your code, you have to sometimes use a process of elimination. Sometimes, it's best to check the easiest possibilities first, regardless of how likely you may think any given cause is. My code was behaving in pseudo consistent ways, something would fail, repeatedly. I would add code to try and catch the error before thing went haywire. I was convinced I had a memory overwrite, or a stack overflow. As soon as I would add the code to catch a problem. It would start working, or stepping though the code would give a different result than running full speed.

Here is a list of things to check while your scratching your head: (In this order)


  1. Fuses. (This turned out to be my problem). I had my fuses set for an external RC oscillator, instead of a crystal. Fuses are so easy to check, it should be the first thing you do. Scrutinize each setting, read the datasheet for each one.
  2. Proper capacitors on the external crystal.
  3. Breadboard noise. I rebuilt my breadboard, it started working better, but not perfect, so I'd assumed it was noise and a memory clobber causing the issues.
  4. Proper JTAG connection. (JTAG seems more sensitive to noise than SPI/debug wire debugging). To eliminate this as a possible cause, program the flash with the "device programming tool" in AVR Studio, using the generate hex file, and use the verify feature. Write some diagnostic code to print to a serial port, then disconnect the JTAG. If your problems go away, it may have been the tool.
  5. Memory stomp. These are pretty common, and can be hard to pinpoint, in pointer arithmetic-heavy code. Stack overflows are particularly nasty and difficult to detect, set breakpoints at your "deepest" code paths, and look at the SP register in the debugger. Comment/stub out large local variables, and eliminate recursion.
  6. Compiler bugs

The last one is actually pretty rare, but it does happen. Odds are you will have found the problem before oyu get to that stage.

--P

Friday, August 23, 2013

Android on the cheap.

Never buy an ubercheap Android device. Android is awesome when done right, but since anyone and their grandma can make one, sometimes that draws you in with their low low prices. I got a $60 4" tablet as a music player on a whim, and I've spent the past two days hoping it would magically decide to all of the sudden not suck. The same goes for phones. It's better to get a phone that was last years' high end phone and/or refurbished than to get a newly released brand new budget level device. I took an in house census recently, and realized our household has 17 Android powered devices, from Cupcake to Jellybean.(Probably half of those get regular use weekly, some are now more sentimental than useful, some are even probably sitting at the bottom of our kids' toybox).  I've modded, rooted, flashed, re-flashed, and re-flashed again custom ROMs, took a stab at compiling kernels, and even published an App, I've come to reluctantly realize I might be a slight subject matter "expert" on the topic of Android devices.

Since most new devices ship with Ice Cream Sandwhich  or higher these days, a great thing to watch out for as far as performance is RAM size. Android 4.X+ just seems to want 1 gig of RAM or more. I've seen ICS and Jellybean on half meg devices but they are almost always janky, while occasionally giving illusions of usefulness. That doesn't stop me from trying a new ROM for some of my aging devices when a I notice a new one on XDA.


I'm sending my latest acquisition back to Grandma... and I'm replacing it with a "major brand" refurb last-year's model. It did cost a bit more than $60, but it has a ton more features too, but the feature I like the best is that it actually works.


--P


Thursday, August 1, 2013

Zaethira Update.

I've made a lot of progress in the past few weeks on my Robot. It had remained dormant for a few months, but I decided to take some time for a context switch to one of my favorite projects. I've got probably 80% of the physical structure built. And the software is probably about 50% done. And the software side of things has made leaps and bounds.

Here's an updated color-coded architecture diagram. I've decided to drop the speaker output feature, mainly because I'm not sure what I'd do with it, but I may resurrect the idea.

Compare to my original chart here

I've got the Pawn scripting working pretty well, I've got some of my low level functionality exposed as Pawn API's, and I've adapted the Chibi/OS shell to treat Pawn bytecode files as "executables" that I can optionally launch in a background thread.

I could probably fill 20 pages with all the developments, but I'm not going to, I just spared myself enough time for a brief post.

Here's a video showing a script running that tries to navigate a square. The compass and and encoder readings are queried in the script to detect 90 degree turns and half meter movements. The compass code is probably beta level, and I'd call the encoder tracking alpha level, so that's why the square is somewhat off. Eventually, I'll have more elaborate geo-spatial reckoning, so that I'll simply command the robot to "go to coordinate x,y, and it will figure out how to get the from the current position(avoiding obstacles too of course). I hope this comes out, Blogger doesn't seem to have an easy way to preview video before publishing a post.

video


I can also control it manually via IR remote controller from a cheap IR helo.


Fun times.

--P