[E3-hacking] Line level conversion

David Given e3-hacking@earth.li
Mon, 14 Mar 2005 21:16:26 +0000

On Mon, 2005-03-14 at 16:51 +0000, Ralph Corderoy wrote:
> Not my strong-point either, but here's another circuit diagram from the
> Hardware Recycling Initiative to throw into the pot.  0.1mF.
>     http://hri.sourceforge.net/tools/#uart

I eventually wired it up with 22=C2=B5F; unfortunately I made a wiring erro=
the first time I powered it up, and I think I've fried the MAX232. It's
registering pretty much open circuit across GND and Vcc, which I suspect
is wrong... anyone know how to diagnose one?

(The wiring error was to connect GND to Vcc --- I plugged it into the
wrong rail on the breadboard. I'm a little suprised that this would kill
the chip, but there you go. I'll have to get another one and try again.)

BTW, I'm using a USB plug as my power source. Pins 1 and 4 provide a
nice handy 5V supply. I'm not sure yet whether you can use the E2's own
USB socket; it depends whether the socket's powered up by default or
not, so for the time being I'm using my PC, making sure all the various
grounds are tied together.


+- David Given --McQ-+ "They laughed at Newton. They laughed at Einstein.
|  dg@cowlark.com    | Of course, they also laughed at Bozo the Clown."
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