Member Since: January 17, 2010

Country: United States



  • The unpopulated chip footprint on the top-right of the yellow PCB appears to be designed for the Apple MFi (Made-for-iPhone) authentication chip, which is supported on this platform (Broadcom WICED.) If you’re prototyping a commercial product and intend to sign a license with Apple for their excellent one-touch WiFi setup this might be a good board to prototype and develop on.

  • Micro. Virtually all new products use Micro-USB.

  • The bootloader is proprietary mojo known as HalfKay and the USB protocol is documented on the manufacturer’s site.

  • It may be possible to compensate for the low voltage by tweaking the contrast or updating slowly, but in my testing about three years ago journeys beneath 2.0V led to the display whiting slowly out like the face of an inexperienced fighter pilot in an aerobatic manoeuvre.

    If you want a great low-voltage LCD consider a Sharp memory LCD. Pebble uses one.

  • Don’t use a supercap and an LDO. Instead, design your 3.3V system to run down to 1.8V or less (many microcontrollers do this) and cut out the LDO completely - they (linear regulators in general) just turn excess voltage to heat, so you’re just wasting all that energy. And don’t bother with a tiny, efficient buck regulator either because at the low operating voltages of supercaps you can usually just run a microcontroller directly, which gives your fine-grained (software!) control of your power use.

  • You might have to bite the bullet and order 25 from Digi-Key to justify shipping. You will no doubt think of projects to build with them!

  • Yes, you can run it at 16MHz. With avr-gcc and avr-libc (which Arduino is based on) clock speed is controlled by a preprocessor definition (F_CPU) - change it and your timing will be right.

  • The small size argument is kind of moot because a surface-mount (e.g. TQFP) ATMega328, which is entirely solderable by hobbyists, is a fraction of the size of even this 8-pin DIP chip. The main reason people (and by this I mean professionals) use ATtinys is because they’re cheap - a tiny25 is about 60 cents in bulk and can still do lots of powerful stuff!

  • This is what makes thermoelectric coolers so impractical for many cooling applications and why they’re typically coupled with a phase-change refrigeration system (which, despite its old-fashioned-ness is much more efficient) in high-performance CPU cooling.

  • I remember seeing a BMW demo where they recovered so many watts of thermal energy from the exhaust that the tailpipe was cool to the touch and the water vapor in the exhaust had almost fully condensed. We’ll definitely be seeing more thermal insulation and recovery optimizations on cars in the future because it’s ‘low-hanging fruit’ for the engineers.

No public wish lists :(