2 years later.....

 Two years since my last post. What has happened in the meantime? Still very involved in Repair Cafe NC (https://repaircafenc.org). I'm retired now. I developed a 90 minute lecture abut the octopus. Will be presenting that on June 4 for OLLI at Nc State. Next big project is a cleanout of stuff I don't need anymore.

Counterfeit Apple MacBook chargers

 This is what is inside a legitimate Apple MacBook charger (after removing the thick copper shield). Circuit board is double sided with surface mount components. The legitimate charger contains a circuit which prevents a defective charger from damaging your $1,500 MacBook.

This is what is inside a counterfeit Apple MacBook charger (with no copper shield to remove). Circuit board is single sided with NO surface mount components. It contains no protective circuitry to prevent a failed charger from damaging your $1,500 MacBook :

Which one is the better deal? Unfortunately, the counterfeit charger is a visually excellent fake. You will not discover this until it damages your MacBook.

Be careful buying cheap MacBook chargers.

Charging Ricoh Theta S and powering from USB battery packs

The Ricoh Theta S is unusually fussy about charging. In my experience, your results may vary with anything except a high quality USB charger, 2A minimum (I use a 2A iPad charger). Also, if the battery runs out, it can be difficult to recharge. Theta S cameras that won't recharge are often interpreted as "damaged", and there is no proof that there is any actual damage. My advice is to use a high quality USB adapter, minimum 2A capacity and a good quality USB cable that uses all 4 pins (not a "charge only" cable). It is OK to use a higher capacity quality charger as the Theta S will only use the current from the charger that it needs.

A USB battery pack can be used to operate a Theta S for extended periods. Some battery packs will turn off while in use...I suspect that the Theta S is not drawing enough current for the battery pack to detect. My solution is to use a Porta Pow Battery Monitor. The Porta Pow is connected in between the Theta S and the battery pack, using the "No DATA + Smart Charge" USB jack. Now the Porta Pow is in charge of regulating current to the Theta S. Cost is about $12.

The Porta Pow is also great for finding the charger that works best with your USB powered device. The display indicates how much current is being delivered.

Use Jekyll for blogs and static web sites

If you want to build a simple, static website or blog, there is nothing easier than Jekyll. If you don't want to pay for hosting, create an account on GitHub and publish a site with Jekyll via pages.github.com.

Jekyll is software which processes files written in Markdown (a simple text markup language) into static web pages.

The advantage of static web pages is that they are lightning fast and don't depend on backend databases to render content.

If the Jekyll software is incorporated into the system that is used to manage your content, then no further work is necessary. Edit your pages and walk away.

Best Lightning connector.....

....by far is the Apple Lightning to Micro USB adapter

Retail cost is $19, but I usually get them from vendors on eBay. I usually pay about $7 to $8. Be sure to get the Apple ones...the knockoff ones don't work and may mess up your Lighting jack. If it costs less than $7, it is likely a non-Apple adapter. How to tell the difference...

The best feature of these is that they don't wear out like the traditional Apple Lightning cables. If the cable gets damaged, swap it out for another. The biggest problem is losing the adapter -- it is quite small. I usually leave it on a cable. Using a short (less than 6 inch) cable makes it very compact.

These are especially nice for folks that need a Lightning cable and a regular Micro USB cable.

EEG and creativity

Since my last post about EEG devices, a lot has happened. I purchased the MUSE headset for $300 and the data was significantly more useful than with the NeuroSky. Not that I am necessarily finished with the Mindwave...I now have 4 of the MindFlex headsets in store for a good project. Not ony does the MUSE provide useful data, their SDK has become quite reliable and includes useful visualization tools. I used the MUSE with PureData running on a MacBook Pro for a music composition class. In one piece, I controlled the levels of various insect sounds based on brain activity. In another, I used EEG data to generate live accompaniment while I watched a video.

The State of mobile device printing

Decided to try printing some of my GameBoy Camera photos from my iPhone via Flickr. First, Walgreens. Their iOS app allowed me to order pictures without creating an account or signing up for anything. Downside is that they only offer 4x6, 5x7 and 8x10 sizes. Their system also reformats non-rectangular photos by cropping. There is likely a way to fix that on the device before sending, but still, an extra step. Target has a photo center in their store, but no way to access via an app. RiteAid was interesting (in a not good way). I downloaded the app, selected the photo center. I was immediately prompted to create a Plenti account before I could do anything. The signup on the Plenti site was graphically intensive and very slow. Selecting the photo center generated a pop up that the site was not functional and that I should go to a specific URL for more info. No link to click or automatic redirect. Rite Aid has shut down their online photo processing due to a data breach. At least they were up front about it.

More on BCI, waiting for OpenBCI

Continuing to experiment with the NeuroSky Mindwave. Using Mindwave OSC on a Nexus S (Thanks Carrie!) which communicates with my iMac over OSC. PureData grabs the OSC stream and presents the data in my pd patch. Getting some interesting results -- the biggest problem is that the data stream seems quite erratic, which makes it difficult to correlate my thoughts with the results. 

Missed the Kickstarter for the OpenBCI interface, but looking forward to trying it out. All of the interface software is open source, which should make it easier to experiment with the different brain wave types. As a bonus, the Open BCI interface is capable of processing EKG (heart) and EMG (muscle) sensors.

Brain Computer Interfaces (BCI)

Commercially available, relatively low cost Brain Computer Interfaces (BCI) and related software

Is it possible to create music with brain waves? It's a work in progress.

You can find all of my links here : http://delicious.com/tkarches/search/EEG

An incomplete summary :

Mindwave Mobile (Neurosky)

• Retails for $99 (Brainwave Starter Kit)
• Works with Mac, Windows, iOS, Android
• A number of iOS apps (search iTunes store with "neurosky") - most cost $$$
• Brainwave Visualizer (Mac, WIndows) shows all brain frequency bands - almost too much data

BioZen software : http://www.t2.health.mil/apps/biozen

• Neurofeedback software
• Free
• Developed by the military to help soldiers
• Runs on Android devices
• Most input devices supported are based on Neurosky headsets

MindFlex and MindFlex Duel - Toys by Mattel that use the Neurosky electronics. Only uses Attention parameter. Headsets can be modified for full EEG output. These are available relatively cheaply on eBay and Amazon (around $50)

Muse - no product has shipped as far as I can tell - currently taking pre-orders

Melon - another EEG headband, shipping Summer 2014

Bitalino - not for EEG, but is a set of physiological sensors for EMG, EDA, ECG along with a light sensor, an accelerometer and an LED. Can be split up into individual modules. Cost is $150 Euro.

I miss record stores

My son and I went to the local mall yesterday where a new FYE store had opened. While the selection is not great, it was just good enough that I noticed that one of my favorite bands, "Los Amigos Invisibles" had a new album. Actually, they have had 4 albums since I last paid attention.

While the internet is a great resource for finding music, being in a record store provides a much better experience for serendipity. I really miss record stores. I used to stop at the old Record Exchange at least twice per week. I loved their $1 bin. You can take a chance on a $1 CD like you would never would for a $15 CD. Some I bought because I liked the cover.

I need to make the effort to go down to Schoolkids records once/week and buy something there at least once/month, or pretty soon it won't be there.

Switching from AT&T to T-Mobile

I recently switched my phone service from AT&T to T-Mobile. I did not have any particular problems with their service. Other than the typical crazy business practices that only mobile phone providers can get away with. I have 3 iPhone 4 devices on my account, and two of them are out of contract. Since T-Mobile has separated the phone subsidy from the service costs, I was able to reduce my phone bill from $190 to $90. This did involve paying the Early Termination Fee for one of the iPhones, which was $145. This was a no brainer as I can make back the savings in under 2 months.

I investigated the differences in coverage, and AT&T's 3G coverage is slightly better than T-Mobile's. Interestingly, T-Mobile's Edge (2G) coverage was slightly better than AT&T.

Having done this, There are other carriers (MVNOs) that will let you "bring your own phone", so your options are not limited to T-Mobile. Understand that these MVNO carriers use the infrastructure of AT&T and T-Mobile, so your coverage will not get any better than it would be with either of those carriers

I have some observations and suggestions for those that may want to consider changing carriers :

• If you are planning to use unlocked phones, make sure you can get them unlocked. AT&T policy is that they will unlock iPhones that are out of contract with no outstanding charges (including ETF fees)
• Carefully calculate your ETF liability. Payback is much longer if you have a substantial amount of contract remaining.
• As contracts on your phones expire, get them unlocked, then test with a non-AT&T SIM to confirm the unlock
• If you wish to keep your existing numbers, initiate the change process at the destination carrier. If you cancel service for your existing phone lines, the numbers will go back into the pool of available numbers
• As for timing, I would switch less than a week before your billing date. This will minimize the time you will have to wait to close out your old account. If you will need to pay ETF fees, the unlock process may be delayed until the final bill was paid. I mistakenly switched a few days AFTER my billing date, and had the potential of having that third phone unusable for 3 weeks. Fortunately, AT&T was cooperative and performed the unlock once I called them to explain the situation. I did have to call them twice, but everything was very cordial.

So far so good. The only thing I miss so far is being able to forward emails to SMS. Setting this up in GMail involves typing in a confirmation code to verify that the destination address is valid. Unfortunately, T-Mobile's gateway cuts off the message after 160 characters and the confirmation code does not make it through.

Ubuntu does not remove old kernels

Ubuntu 12.10 does not do a good job of cleaning up old kernels. If you do a default install and allow Ubuntu to partition your disk, the /boot partition may fill up with no warning. Easy solution : install Ubuntu Tweak to clean out the old kernels.

Once installed :

1. Run Tweak and click the "Janitor" button
2. Click the checkbox next to "Old Kernel" under "System"
3. Click the "Old Kernel" checkbox on the right, then the "Clean" button at the bottom right.

If you want to keep some of the old kernels, click the arrow next to "Old Kernel" checkbox, and they will be listed individually. You can then choose which to delete and which to keep.

Don't recycle electronics, repair them

Don't recycle, repair. My wife is now using two 20 inch Samsung LCD displays that I repaired with a well documented fix found on the internet. Spent about $4 in parts and an hour of my own labor. They were about a week away from being in the landfill. If your late model Samsung or Phillips LCD display/flat screen TV has recently stopped working (my Samsung LCD TV died about 4 years after its' purchase), it is probably easily fixed. --tom

Java is a 4 letter word

Got this today from a friend : Java users beware : Exploit circulating for just patched critical flaw So, Oracle just patched Java (again) and almost immediately that patch is being patched. If we were to sum up the cumulative misery (lost time, lost work, endless patching) that Java has inflicted on humanity, it would be a big number. The whole concept of "the same code runs everywhere" NEVER really worked. Whose time are we saving? --tom

I found an Optigan!

This past weekend, I found something from my musical "Holy Grail" list....an Optigan! The Optigan was built in the 1970's by Mattel Corp. (yes, that Mattel) in Compton, California (yes, that Compton). Wikipedia has a pretty good overview : http://en.wikipedia.org/wiki/Optigan The Optigan used samples recorded on circular film stock that looks like a vinyl LP, but you can see through it. Each key on the keyboard was mapped to a separate track on the optical disk. There were also tracks for the chord buttons and 5 special effects buttons. The Optigan was built by a toy company, thus the dodgy build quality. Some internal parts would disintegrate, the rubber idler wheel would get hard and the disk would slip. Nonetheless, the Optigan and its' low-tech sampling capablity has appeared in many commercial recordings (and still does to this day...check out the Optigan Facebook page). My main interest is historical. Here is my Picasa album of the teardown. When I brought it home and plugged it in, for the most part, it worked (this is unusual for Optigans). The special effects buttons were intermittent so I had to take off the top to access the buttons. To remove the top, the sides must be removed because they cover the screws that hold down the top. Yay. The pictures show the state of the internals. Not so bad. While reassembling, a small wire which moves the disk assembly fell out. In order to reinstall the part, I had to pry out an internal panel, replace the part (with forceps) and screw it back together. Another common problem is the idler wheel. The rubber has turned hard and slips on the disk. It can be resurfaced, but requires major disassembly to remove the part. Once I have a service manual (or at least a procedure), I may attempt this.

Raspberry Pi, Puredata and MIDI

My initial test with the Raspberry Pi running Puredata did not go as well as I had hoped. Noticeable noise in the output audio. In my MUS306 class today, MIDI was the topic of discussion. Why not MIDI? Connected my $5 no name MIDI interface to the Pi and started Puredata. Changed the configuration to turn off the audio output and set the MIDI ports. Used my Yamaha QY-10 as the MIDI tone generator. Everything worked perfectly. Now I'd like to see if I can attach controls directly to the GPIO port. This would save me from having to attach another MIDI device.

Hammond Tone Generator - Part 3 - FInding the usable tonewheels

I have tested the outputs of the tone generator...there will be about 60 usable outputs. The other 31 outputs consist of the lower frequencies..the windings on the tonewheel cores include resistance wire which drops the levels significantly. I will have to further dismantle the TG to see if the resistance wire can be bypassed. I don't think that further dismantling is worth the potential of damaging the TG. I know that at least 2 or 3 of the tonewheels are stuck and will be looking at those to see if I can get them working. Fortunately, there appears to be a correlation between the color of the wire from the tonewheel and whether I am seeing usable output. For example, none of the red wires produce usable output. Most of the orange wires provide usable output. If I'm not getting output from an orange wire, something is probably stuck or broken. I have documented all the wire colors and whether I am seeing output. Next step is to recheck the outputs that should be working.

Hammond Tone Generator - Part 2

I have tested all the outputs of the Hammond tone generator. Some of the levels are lower than others, but all are generating output. The levels are too low to be switched by anything other than physical switches, so they must be amplified. Many of the tone generator (TG) outputs are filtered through a LC filter to suppress harmonics and reinforce the fundamental. If I were to bypass this filter, I would have higher levels from each of the TG outputs. Unfortunately, the harmonics are clearly audible without the filter, so the filters must be retained. The lowest 42 tones have resistance wire wound into the coils, which is required when the TG outputs are connected to the various busbars in the organ, but not necessary if I were to replicate the Hammond wiring scheme (61 keys x 9 wires per key = 549 wires per manual). I plan to use the TG in a more novel way, which has yet to be determined. The TG output levels can be increased by moving the core closer to the tone wheel, but external amplification will probably be required.

The amazing Deacy amp

Was listening to Queen's Greatest Hits and was looking up the band members on the internet. Turns out the bassist, John Deacon, was an electrical engineer. In the early days of the band, he FOUND a amplifier circuit board on the street and decided to try and make it useful. He put the amp in a spare speaker cabinet and the Deacy amp was born. http://www.brianmay.com/brian/briannews/briannewsjun05.html In combination with May's Red Special guitar and a treble booster pedal, the classic Queen guitar sound was born. Expensive replicas have been built : http://www.astrings.co.uk/deacy_amp that achieve 85% of the sound. :-)

Hammond Tone Generator Project - Part 1

Early this year, I acquired a tonewheel generator (TWG) from a Hammond series H organ. The H series was rushed into production to compete with offerings from other organ companies, and suffered reliability problems as a result. Here are some photos :

The Tonewheel Chronicles

This TWG had already been removed from the organ and was headed for the dumpster when I picked it up. I have bolted it to a wooden frame to prevent flexing. The Hammond tonewheels organs were produced from 1935 until 1975. Tones were generated by spinning a toothed steel wheel next to an electromagnet. The wheels rotated at a fixed rate, locked to the speed of the synchronous motor. When operating properly, the TWG never went out of tune. This was an improvement over electronic oscillators, where at least 12 oscillators must be tuned to their appropriate pitches. Here is a more extensive description : http://en.wikipedia.org/wiki/Tonewheel So, what can you do with a TWG from a Hammond organ? First, I needed to test the TWG to make sure that it was operating properly.