• Hardware

    ATTiny85 PWM from Timer/Counter1

      I’ve been tinkering with the ATTiny chip a bit lately, and I wanted to hook up of my stepper motors to it. This chip has 2 timers, and a few pins that can output PWM signals. I had OC1B on PB4/pin3 free, and the Timer/Counter1 module looked a bit better than the Timer/Counter0 module for the relatively-long pulse needed to control the stepper motor. First thing to figure out is what I wanted the PWM signal to look like. Stepper motors care more about the pulse length than the frequency. My motor accepted 700-1500us as the control range, so I decided to go with a 4000us period (250Hz). The…

  • Hardware

    Small Run Fab Services

    For quite a while I’ve been just using protoboards, or trying toner transfer to make pcbs, with limited success. A hackaday article (Why are you still making PCB’s?) turned me on to low cost, prototyping pcb runs. Cutting my own boards via toner transfer had lots of drawbacks: I’d botch my transfer (as seen above), and have to clean the board and start over again. Chemicals are no fun either. Drilling is tedious. I never really got to the point where I’d say it was easy to do a one-sided board. I would always route one-sided boards, as I never got good enough to want to try a 2 layer…

  • Hardware,  Open Source

    SVG Hardware Drawer Labels

    I recently made a set of SVG labels for my hardware small parts bin in Inkscape for the common Akro-Mills 10164 small parts organizer. Its sized to print the labels the correct size on a 11″x8.5″ sheet of paper (results may vary, so make sure to resize for whatever drawer and printer you have) I thought I’d share them here in SVG format, which should make it pretty easy for you to download and customize. (Eg, you could change the resistor color codes to your set of resistors, change the values, etc). If you do sink a lot of effort into adapting the file, please share-back (open source!) via the…

  • Hardware,  Reviews

    Saleae Logic 8 Review

    Over the break, I got to play a bit with the Saleae Logic 8 logic analyzer. Its the mid-range model from Saleae, and it works with Ubuntu. I wrote about the predecessor to the Logic 8 a while back, before Linux support was around. I finally got to do a bit of tinkering with the new device, under Ubuntu Vivid. The device itself came packaged only in the carrying case that is provided. Inside the zippered carrying case was the Logic 8 itself, 2 4×2 headers with 6-inch leads, 16 logic probes, a micro-usb cable, a postcard directing you to the support site, and a poster of Buzz Aldrin in…

  • Hardware,  mir,  Ubuntu

    Mir Device Showcase!

    Here’s a video of Mir powering a few different GPUs: Nexus 10 (ARM Mali T-604 GPU) Nexus 4 (Qualcomm Adreno 320 GPU) Nexus 7 (2012) (Nvidia Tegra 3) Galaxy Nexus (PowerVR) This is a pretty big milestone, as we’re now in a position where Mir works well with 4 big Android gpu vendors. Enjoy! The only disclaimer on the video is that some of the code hasn’t trickled to the images yet, and the tablet support is still a work in progress. Onwards and upwards!

  • Hardware,  Random

    Why we Make

    This is a great talk about the fundamentally human aspect of making. Our race’s advantage in the universe isn’t the sharpest claws or thickest skin, its the ability to make, bend, and discover. This video is an cool little anecdote from Adam Savage of mythbusters of how he embraced his inner maker: People make things in all different sorts of ways, from a 4 year old making arts and crafts to a professional engineer building the Space Station (or a world class operating system 🙂 ). Its fundamental to being human, so get out there and create!

  • Hardware,  Random

    Legos and Turing machines

    Jeroen and Davy over at legoturingmachine made a pretty cool little turing machine to honor Turing‘s centennial birthday. I thought I’d repost! Check out the video: LEGO Turing Machine from ecalpemos on Vimeo. Pretty cool way to honor the theoretical basis for all modern computing!

  • Coding,  Hardware,  Random

    Android ARM inline assembly

    If you happen to want to write some inline assembly in Android, its just about as easy as you’d expect! See the code snippet below for a simple example of how to add two numbers in assembly on ARM. Download code with Android makefile [code lang=”c”] include "stdio.h" static inline int add(int a, int b) { int sum; __asm__ __volatile ("add %[c][/c], %[a], %[b]" : [c][/c] "=r" (sum) /* one output */ : [a] "r" (a), [b] "r" (b) /* two inputs */ : /*code does not clobber*/ ); return sum; } int main(int argc, char ** argv) { printf("sum is %in", add(4,222)); return 0; } [/code] If you run…

  • Coding,  Hardware,  Open Source

    Installing the blob on your Pandaboard for Android

    The Pandaboard by Texas Instruments is a pretty good, mostly open source little development board with one teensy problem…. the blobbbbbbbbb (illustrated by Hermes Conrad to the left…) If you’ve followed this blog post from last week, you have an image that was built from source, and is identical to the images that linaro produces. However, you still have to go and install the binary drivers provided by TI to get things like graphics acceleration working. I’ve been using a script by vishalbhoj from linaro here. Pretty much, if you read it, it just has a download location, and then conveinently installs the download to the proper partition on the…

  • Coding,  Hardware,  Open Source

    Building Linaro Android (12.04 or daily) for Pandaboard

    I recently came into possession of a TI pandaboard for ARM development. Its a pretty cool little package, but if you want to build from source, you run into all sorts of old outdated wiki’s from Linaro that have you chasing your tail trying to build the android tree from source. Here’s how you do it as of May 2012 You have to get a ARM cross-compile toolchain and an android source tree that are in sync with each other. This is the tricky part, because its not exactly well tagged on the internet which version of the toolchain will work with what version of the source tree! When I…