It's curious that it can be passively checked or tied to an interrupt.I read
one of the Portable 100 articles about attaching a photo transistor to it which
got me thinking about a few projects. I think it was being used as a stopwatch
for that application. But it's definitely a port with possibilities.
Kurt
On Thursday, June 18, 2015 3:22 PM, MikeS <dm...@torfree.net> wrote:
It's actually a pretty useful port and the +5V availability is a real plus.
There's a Portable100 article about using it as a tachometer (although ISTR
that the software left something to be desired) and although I haven't tried it
it should be a straightforward interface for a temperature- or
voltage-to-frequency converter (e.g. Maxim 6576 & 6577, Analog AD7740 etc.,
even just a 555). If memory serves, I think Steve did something like that for
his aquarium heater or something similar. And you can even use it to read bar
codes! m
----- Original Message ----- From: Kurt McCullum To: Model 100 Discussion
Sent: Thursday, June 18, 2015 5:39 PM Subject: Re: [M100] Barcode Wand
Thanks for the info!
On Thursday, June 18, 2015 2:14 PM, Doug Jackson <d...@doughq.com> wrote:
Yes,
>From memory, the wand has *no* smarts - the phototransistor is basically
>converted to TTL and provided to the interface pin.
It was very similar to the HEDS3000 series wands that HP used on the HP41
(http://www.ecse.rpi.edu/Courses/CStudio/data%20sheets/HEDS3050.PDF) I have
both the TRS80 wand and the HP in storage here if anybody wants information.
Doug
On 19/06/2015 6:56 AM, Kurt McCullum wrote:
Does the barcode interface use a TTL level signal? Meaning any TTL barcode
scanner that is wired properly could be used?
Kurt
--
Kindest Regards,
Doug Jackson
<b>Dougs Word Clocks.com Pty Ltd</b>
ACN: 159 352 753
35 Fred Lane Crescent, Gordon, ACT, 2906, Australia
em: d...@dougswordclocks.com
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