[HH] Digispark Arduino-compatible boards now at Micro Center for $6

[Tom Metro]

I saw these in the latest Micro Center flyer and didn't recognize them
due to them using a photo of the underside of the board, rather than
showing the side with the PCB traces used for the USB connector.

Back in September I posted some details on these (after Drew Van Zandt
posted a link):

> Aside from being inexpensive, the Digispark looks
> to be about a 1/2" square (actually .7" x .75") PCB with a tab sticking
> out on one side to form a male USB plug.
> 
> Arduinos are starting to approach the size and price of "LED throwies."  :-) 
> 
> Notable that it is fully open source hardware.
> 
> Here's the Kickstarter page:
> http://www.kickstarter.com/projects/digistump/digispark-the-tiny-arduino-enabled-usb-dev-board?ref=home_popular

Would you believe they're selling for $6? 10+ units in stock in
Cambridge. (It says "Originally $9.95." When was that? As far as I know
they just started carrying them in the last 30 days. They sell for $8.95
directly from the manufacturer. The $6 price doesn't appear to be a
limited duration sale price.)

Digispark USB Development Board
http://www.microcenter.com/product/409634/Digispark_USB_Development_Board#

  This USB Development Board is an Attiny85 based microcontroller
  development board similar to the Arduino line, only cheaper, smaller,
  and a bit less powerful. With a whole host of shields to extend its
  functionality and the ability to use the familiar Arduino IDE.


Looks like it comes with a couple of connectors you can optionally
solder on if you want to temporarily connect it via jumpers to a
breadboard, or attach the shields (see below).

Here's the manufacturer's site with more details and better pictures:
http://digistump.com/products/1

A bunch of "shields" (peripherals) are available:
http://digistump.com/category

covering expanded digital I/O, RGB LED, LED matrix, IR receiver, motor
driver, relay, LCD, non-volatile memory, and others. Most priced under
$10. Most are sold as kits with some soldering required, but they all
look pretty trivial. You can also opt to buy just the PCBs for about $2
each.

A $15 starter kit bundles a Digispark with the RGB LED shield and a
prototyping board (just a square perf board with header pins to mate
with the Digispark when the optional connectors are attached).

They also sell a $4 programming accessory that basically just acts as a
USB pass-through connector with a switch so you can power cycle the
Digispark without unplugging it. Seems like they should have included
that, instead of the RGB LED shield in the starter kit.


Remember that USB connected indicator light peripheral we talked about
here a while back? I think it sold for something like $30. You could
combine a $6 Digispark with a $3 RGB LED shield, and with some D-I-Y
assembly and packaging, have the equivalent hardware capability, with
the added bonus that you can easily reprogram it.

Need a hardware watchdog to power cycle a small device if it crashes? $6
Digispark + $7 Relay Shield Kit (relay handles 3A at 125VAC). (I'm assuming
it would be easy to program a Digispark to receive "I'm alive" signals
from the host device via USB.)


According to:
http://digistump.com/wiki/digispark/tutorials/connecting#using_the_digispark_with_the_arduino_ide

as long as you are using their customized Arduino IDE, you just plug
your Digispark into your host computer and hit the upload button in the
IDE to program it.

They note:
  If you unplug the Digispark and plug it back in or attach it to
  another power source there will be a delay of 5 seconds before the
  code you programmed will run. This 5 second delay is the Digispark
  checking to see if you are trying to program it.

That startup delay could be a serious limitation in some application, so
something to be aware of.

 -Tom