A nice display for Raspberry Pi

I needed a compact computer setup for my cramped electronics workbench.  The SunFounder 10.1 inch display is both space- and cost-efficient.  Instead of using molded parts for the case, SunFounder uses laser cut acrylic sheets, presumably to keep the cost of production down.  A Raspberry Pi computer can be mounted behind the screen.

Although it has a few minor quirks, the SunFounder screen represents a great value.  Recent price on Amazon was $110.99.  Add a $25 RasPi, keyboard and mouse and you’ve got a very capable little one-piece computer for under $150.

What I like about this display:

  • 1280 X 800 pixel resolution is more than adequate for running a browser or a few terminal sessions
  • As claimed, the IPS LCD screen has a very wide viewing angle.  I also found the color saturation and contrast to be excellent
  • Built-in speaker
  • It has VGA and composite inputs in addition to HDMI

And a few deficiencies:

  • The monitor arrived with several loose screws.  Seems whoever assembled my unit didn’t have a screwdriver that day
  • I needed to dremel one of the acrylic plates that holds the RasPi in place to make it fit properly
  • An onboard source of power for the RasPi would be welcomed.  I suspect that a 5V connector that taps internal power could be added for less than the IR remote control that comes with the display.  What possible use is a remote anyway?  I can’t envision ever being more than arm’s length away for a screen that’s only 10 inches wide.

    My kludgy solution was to velcro an extension cord to the back, connecting separate power bricks for the display and RasPi:

  • Out of the box, I was getting no sound from the display.  The printed instructions that came with the it said to run raspi-config and choose the option to force audio out through HDMI.  But that did not work because the computer was detecting the SunFounder screen’s interface as DVI, which is not audio capable.  The solution was to add the line hdmi_drive=2 in config.txt to force HDMI mode.

These minor nits aside, for the price of a cheap Chromebook, the combination of the Raspberry Pi and SunFounder display provide several features that are useful on my workbench and would not be available on other similarly priced platforms like a  built-in serial port, gpio pins and the ability to display HDMI, VGA or composite video.

Next project, a perfect companion for this setup:  let’s dust off an Apple Newton keyboard and add USB connectivity to it.

Repairing an iMac Power Supply

A 24″ iMac that wouldn’t start up came in for repair.   Pressing the power button got the fan to briefly run then shut off.  It never reached the point where there was a happy (or sad) chime.  The owner’s first inclination was to toss the computer after we wiped the hard disk but I told him we could probably get it running for the cost of a new power supply (around $75).

Using the always great disassembly instructions at ifixit.com, I got the front bezel off the iMac and checked the logic board diagnostic LEDs.  LED 1 was on and LED 2 came on briefly when I tried to start the computer, indicating that the logic board was probably fine and the problem was with the power supply.

Several disassembly steps later I had the power supply board out of the iMac.  From a quick visual inspection, I could see that some of the  2200 µF capacitors were leaking a bit and one had developed a considerable bulge at the base.  Maybe we could do a cheap repair here?

I clipped the four suspicious caps out (to get an accurate measurement) and checked them with my Fluke 179 multimeter–quick side story:  this DMM is so rugged that it survived a total loss house fire with only minor cosmetic damage.  All the capacitors were out of spec but interestingly the one that looked the worst actually measured closest to good.

Easy peasy fix, right?  LOL, not exactly.  This board uses lead free solder, which is a total pain to remove.  Even with my trusty Hako soldering iron cranked up to 800º, the PCB’s heavy copper traces made it a challenge to keep the solder molten long enough to suck it up with a desoldering tool.  An hour of determined effort and cussing later I had the old caps out and the through holes cleaned out.  (I needed to ream most of the holes to get the last bits of lead free solder out).  Four new shiny black capacitors installed without any drama.

Shiny new capacitorsAll LEDS Normal

I reinstalled the power supply module and the iMac started normally with 4 LEDs lit on the logic board.  I also installed a new button battery while the iMac was open.  Total cost of repair: under $2 🙂

If I were to attempt a similar repair again I wouldn’t bother with trying to remove any components from the circuit board because of the lead free solder.  The job wouldn’t look as pretty, but it would be a lot easier to just leave the old leads in place and solder new parts onto them.

Controlling devices with Indigo and Amazon Echo (Alexa)

A recently added plugin for the superb  Indigo Smart Home Software platform enables voice control of devices like lights, thermostats, fans, shades and garage doors–to name just a few–via an Amazon Echo DotEcho or Fire TV.  It works seamlessly with the Lutron RadioRA 2 plugin that I developed and is also presumed compatible with the Lutron Caseta Smart Bridge Pro (although this has not been formally tested yet).

The plugin works by emulating a Philips Hue bridge.  Setup is easy.  Just install the plugin and select the Plugins->Alexa-Hue Bridge->Manage Devices… menu item.  Choose the devices you wish to control (up to 27) and then tell Alexa to discover your devices either by saying that or by using the Alexa app.

The 27 device limit is set by Amazon’s Alexa implementation, however, if you reach that limit, you can set up a Device Group in the Virtual Devices interface to group devices are typically controlled together into a single device.

Alexa currently recognizes only “turn on”, “turn off”, and “dim” commands, however, it’s possible to control devices that don’t natively support on/off/dim by creating virtual devices.  For example, I created a virtual device called “heat” that controls a RA 2 thermostat.  When I get a chill and say “Alexa, turn heat on”, it invokes an Indigo Action group that sets the nearest thermostat to 74 degrees.  “Alexa, turn heat off” sets the thermostat back to 68 degrees.

If you’re already running Indigo, I highly recommend adding a modestly priced Echo Dot to seamlessly add voice control to your automation setup.

Thoughts on the Apple Watch

I’ve been living with an Apple Watch for a month now (stainless steel case/Milanese loop band).  Overall, I think it’s great.  The most common criticism that I hear about Apple Watch is that there is no “killer app” that creates a compelling new product category.  This is absolutely true.  However, the real value of Apple Watch is the cumulative effect of its numerous and sometimes subtle features.

It’s the little things that count

Right off the bat, it’s easy to appreciate that the Watch is a beautifully crafted piece of jewelry (photos of the Milanese band don’t do it justice;  you need to see it sparkle in sunlight).  But it takes several days of wearing Apple Watch to get a full appreciation for its capabilities.

The best features of the Watch are not activated by direct user interaction but just seem to happen at appropriate times.  Case in point:  the first time I used the Map app on my iPhone to get driving directions I was pleasantly surprised to learn that I didn’t need to see or hear the phone to know when to turn.  The watch tapped my wrist with three double taps when I needed to turn left and with a steady series of twelve taps for right.

The Activity app won’t turn me into a marathon winner overnight but it succeeds in prodding me to do a little bit extra every day.  It sets daily goals for moving, exercise and standing.  Several evenings I found myself just short of goal right before bedtime and made up the difference with a quick exercise session.  This wouldn’t happened if the watch wasn’t giving me frequent encouragement (including virtual “awards”) to hit all my daily goals.

The Watch reminds me to stand if I’ve been sitting too long.  And it provides a weekly and periodic activity reports that encourage me to stay on top of my goals.  The cumulative effect of these little “nudges” should be a lighter, healthier me.

Size matters

It’s been reported that around 70% of the Apple Watches sold to date are the larger 42mm models.  I think the majority of the people people buying these are wrong for the following reasons:

  1. On all but the largest wrists, the 42mm case looks dorky.  There, I said it.  The 38mm watch has a more conventional size and looks elegant on both men and ladies.  But Apple doesn’t always make it easy for men with larger wrists to get a 38mm model that fits.  For example, if you’re a man in the market for a stainless steel Watch with the elegant Milanese loop band, you need to step up to the 42mm case (for an extra $50) if your wrist is larger than 180mm.  Apple should offer a large Milanese band option for the 38mm Watch.  Bigger guys who want a 38mm case with a stainless band will need to shell out an extra $300 to step up to the Link Bracelet.
  2. Yes, the larger watch has slightly better battery life.  But this is irrelevant because neither model will make it through two full days on a charge.  Whether you have a 38mm or 42mm watch, you will still need to take it off every night for charging.
  3. The larger screen doesn’t really offer much in terms of better ergonomics or readability.  I haven’t experienced any problems with the 38mm Watch recognizing exactly which object I’m trying to tap.

Some room for improvement

My main nit with the Apple Watch is that I need to rotate my wrist slightly more to activate it than I would to glance at a conventional watch.  It would be great if there was a user configurable sensitivity setting for the “Activate on Wrist Raise” feature.    With 40% power remaining after a typical day, I wouldn’t mind if the Watch sacrificed a little battery life to activate less conservatively.

According to Apple, the Watch and iPhone that it’s paired with are supposed to be able to communicate over a trusted WiFi network when they are out of Bluetooth range.  This doesn’t seem to work reliably in my house but it might have something to do with having multiple Ubiquiti long range access points installed (although this setup is seamless with all the other WiFi devices I use).

I’d prefer a thinner case, but to Apple’s credit, the Watch looks svelte next to most smart watches.  (Curiously, it looks thinner on my wrist than off).  I have no doubt that Apple will figure out a way to slim subsequent models down as they have done with every other device.

Apple should sell a proper charging stand for the Watch.  However, the Nomad Stand is an attractive option (albeit a tad expensive at $70 for a piece of twisted aluminum).

Minor gripes aside, the Apple Watch is a fabulous first generation product and I highly recommend it.

Microsoft Surface Pro 3 first impressions

My office is replacing its aging fleet of HP 620 notebooks with Surface Pro 3  (256 GB, Intel Core i5) tablets.  Each tablet will be deployed with an optional keyboard cover and docking station.  This is the middle-of-the-road model, which is powerful enough to run most business applications but not suitable for more demanding video or graphic editing tasks.

The Surface Pro works well as a tablet replacement.  Although it’s somewhat clunky compared with Apple’s iPad, the build quality and overall feel are solid.  The built-in kickstand adjusts to a wide range of viewing angles and folds flat when not in use.  The power connector, which attaches magnetically similar to Apple’s MagSafe plug, is a bit awkward to plug in because of its width and the Surface’s beveled edge.  The sharp edges make the Surface Pro less comfortable to hold than an iPad.  The touchscreen is responsive and the display is bright with well saturated colors.

As a notebook replacement, the Surface Pro leaves a lot to be desired. The optional keyboard cover is both ingenious and frustrating.  The cover attaches magnetically.  Unlike the power connector, it attaches without any fuss and is easy to position even in dim light.  It can either lay flat or the back can be raised a bit by folding a section at its back. Both positions have flaws.  The tipped-up position achieves a more natural typing angle, but the not rigid enough keyboard cover flexes considerably.  The flexing disappears when the keyboard is in its flush position but I found it uncomfortable that way for long typing sessions. The trackpad is imprecise and I frequently found myself reaching for the touchscreen instead.

By no means should you call the Surface 3 Pro a laptop!  Trying to use the Surface on your lap is an exercise in discomfort and frustration.  The sharp edge of the kickstand digs into your legs and the keyboard cover flops around like a dead fish.  And you will look like a dork.

A stylus is included with the Surface Pro 3 but it isn’t particularly useful.  It took some considerable head scratching before I figured out that the stylus only works with Microsoft OneNote and a handful of apps.  I don’t see any good reason why it isn’t recognized by the general touchscreen interface.  The Surface doesn’t provide any place to stash the stylus.  If you buy the optional keyboard cover you get a flap of material with a loop to hold the stylus.  It has a self-stick backing that can be affixed to the cover but it looks goofy and would probably rip off after a week of use.

The docking station provides a full set of ports and comes with it’s own power brick.  It positions the tablet at a good viewing angle and has a conveniently located magnetized area along the left side to hold the stylus.  I struggled with inserting and removing the Surface from the docking station until I realized its sides slide in and out.  (Yeah, I know, RTFD, but there aren’t arrows or any other kind of visual cues.  This should be more intuitive.)

Overall, the hardware isn’t half bad.  However, the UI is a hot mess!   The Surface-specific annoyance is that the OS doesn’t automatically adjust when the keyboard cover is affixed or removed.  After disconnecting the cover and heading out without it, there was no way to unlock the tablet because the password field wouldn’t present a “soft keyboard.”  Conversely, I wasn’t able to connect and use the keyboard to finish a document that I started in tablet mode.

Other annoyances are just because the Surface Pro 3 runs Windows 8.1.  The GUI is wildly inconsistent and switches between “classic” Windows and the new Metro look depending on what you are doing.  This schizophrenic UI must be baffling to users migrating from Apple platforms!  I’m thinking about disabling Metro entirely so at least I can get a consistent user experience.

Bottom line: the Surface Pro 3 is a good choice if you’re looking for an ultra-mobile computer to leverage existing Microsoft licenses or mainly use Windows-only applications.  And you want the ability to use it as a touchscreen tablet.  Otherwise, the similarly sized 11-inch MacBook Air, which has a “real” keyboard and intuitive OS is worth a look.