Long ago, before the days of LEDs. LCDs and vacuum fluroescent displays there was briefly a display technology known as the Nixie tube. A backronym standing for (N)umeric (I)ndicator e(X)perimental, these glow discharge tubes (think fluoresent signs) could display numbers. The former Soviet Union produced and used these quite a bit in things like calculators and scientific equipment.
I recently read about Nathan Griffith’s Nematoduino, a full brain simulation (all 302 neurons!) of a nematode on Arduino, with great fascination. I thought it was soooooo cool and immediately wanted one of my own. The source code was released, but unfortunately no hardware diagrams came along with the code. I read through the code and determined that H-bridges were needed — I did not have these on-hand. I did, however, have an Adafruit Motor Shield. I decided to adapt Nematoduino for my hardware and I was successful with very little effort.
It was actually very easy to adapt. The author is setting motor speed using 8 bit resolution, the same as an Adafruit Motor Shield would. I changed his motor commands slightly to signal the motor shield in terms of speed and direction. I made some minor pin selection changes, making pin 13 the indicator pin for the ping sensor. I also disabled the stop/start push-button switch out of convenience but this easily re-enabled.
I was then able to load up my sketch and enjoy my nematode!
My circuit diagram from Fritzing:
The sketch for my build can be obtained here.
I recently built a new home audio system and decided it would be fun to experiment with vinyl given how trendy it has become. I should have known right from the get-go that I would I would wind up going a little too far, in typical audiophile fashion.
I had purchased an Orbit turn-table from U-Turn Audio was quickly having all too much fun. I equipped mine with the acryllic platter and Ortofon 2M Red cartridge. I opted not to get their Pluto pre-amp as my Parasound amp includes a phono stage. This was great for getting started but left something to be desired, as with many built-in phono stages.
After some research, I came upon the Muffsy Hi-Fi Phono Pre-Amp and Power Supply kits. I’m pretty handy with a soldering iron and so this looked like a lot of fun. I purchased the phono pre-amp and power supply and it was shipped in no-time. I already had some OPA2134 op-amps on hand (the upgrade option) so that was helpful.
I recently upgraded my home audio arrangement and wanted to be able to stream content via AirPlay. The seemingly obvious choice was the Apple AirPort Express as it has a TOSlink audio output. I bought one and found myself listening to a symphony of pops and clicks. It was unpleasant and totally unlistenable.
As I had used the AirPort Extreme with some success in the distant past I assumed the issue lie with the Parasound Halo Integrated amplifier (which includes a DAC).
Further research revealed that the Apple AirPort Extreme (current generation) is in fact, a piece of a shit. Its digital output is known to be very jittery and the ESS Sabre 32 DAC in the Parasound is not at all tolerant of this. I was then left with the question of what to do next.
I did some web searches on the topic and uncovered a company called HiFiBerry that makes a number of audiophile-grade products for use with Raspberry Pi. I was already familiar with a Linux distro called MusicBox which is a turn-key AirPlay receiver (among other things).
I ordered the HiFiBerry Digi+ Pro and waited anxiously for it to arrive.
I set it up (which was a breeze) and suddenly I had TOSlink and 75 ohm coax digital connectivity. I opted for coax. Since then streaming over AirPlay sounds amazing. I play a lot of lossless content and the performance is flawless.
I recommend this to anyone looking for a similar solution. My final solution was to use a Raspberry Pi 3 with the Digi+ Pro and HiFiBerry’s steel case. I am using Ethernet as latency is always better, but I did test WiFi and it worked well for me.
My HiFiBerry setup sitting atop the Parasound Halo.
After building Pi GRRL a few weeks back as a gift, I decided I very much needed one of my own. I just completed it.
I built it very similarly to the other one, using the Adafruit soft tactile buttons for the DPAD and ABXY keys. I decided to used the firmer push-button switches for select/start. I find this cuts down on accidental presses and feels great.
My wife was recently away traveling and I decided that I wanted a project to keep me busy and out of trouble in her absence. I determined that I would build her a custom clock while she was gone. I began sketching out my design and found some great parts on Adafruit for my project.
I was reviewing some of my old drone photography the other day and found a really great shot but the lighting was just a bit off. My friend Asher Haig was kind enough to tune-up this image for me.
This is another shot taken at lovely Lake Lynn in Raleigh. I am about 20 feet up over the water and out a ways over the lake. This photo is from August 21, 2015 and was taken at dusk.
My latest creation came out of a bit of nostalgia. I used to work for NetApp, a major player in the data storage industry. During my time there, I used a FAS3020, purchased on eBay, as a learning tool. I’ve since gotten rid of the filer itself but could not bear to part with the bezel. It was a souvenir of sorts.
I recently uncovered the bezel in my parts closet and realized that a common 16×2 LCD screen fit the bezel perfectly. I have many an Arduino on-hand and I also had a DS1307 I2C-based real-time clock. A short while later, I had it up and going!
The parts used include:
– Arduino Uno microcontroller
– Generic DS1307 I2C Real-time clock (search eBay or Adafruit)
– Adafruit RGB LCD shield kit
I am cleaning-up the code a bit and will then post it on Github.
There is a new petition on WhiteHouse.gov relating to drone’s being shot down all across america. Worse yet, these people are seen as heroes when in-fact they are just reckless vandals. This petition asks the DOJ and the FBI to prosecute such crimes as they should be for shooting down an air-craft which is a federal crime.
Please sign the petition here to protect our drones!