Sun Oct 6 11:31:21 EDT 2013
- an improvised connection for in-circuit programming. Later on,
this will be replaced by a "bed of nails" that connects directly
to the test points.
- battery and switch, not yet mounted. They're both huge and make
soldering other things more difficult, so they'll go last.
- the MCU
- Micro USB AB. The connector looked intimidating because the
signal pins are hidden under the shell, but turned out to be easy
to solder. Not tested yet. I also didn't populate the ESD
- memory card holder. The geometry of this one needs checking. Some
of the pins almost miss their pads. I think I managed to get
everything connected, though. Not tested yet.
- lanyard hole. The PCB around it looks quite fragile ... and it
is, since that bridge that should be about 1 mm ended up being
only some 0.5 mm. Have to tweak some milling parameters. In any
case, this isn't supposed to be a load-bearing element.
Here's the top side:
At the bottom, one can see a Freescale FRDM-KL25Z that I use as
programmer for now. On the Anelok, only two groups of components
- the LED
- transceiver with crystal. It can't do much without the actual
RF parts (balun and a few caps) but this already allows me to
check that the chip comes up and that the crystal oscillator
I've written a few lines of test firmware to blink the LED:
The next steps are to add the boost converter and the rest of the
power circuit (reverse polarity protection FET, memory card power
gate FET, silo cap for RTC in deep sleep). But that's for another
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