Re: The joy of FORTRAN

On 3/10/25 2:18 AM, rbowman wrote:

On Sun, 9 Mar 2025 22:50:20 -0400, c186282 wrote:
 

    For a long time, the only electronics place was a "Lafayette" -
    albeit 15 miles away in the next town. The corp still exists, but
    it's online-orders only :
>
    https://www.lafayetteelectronicsupply.com/

 Other than a guy with a cellar full of salvaged parts there wasn't much
local so it was mail-order from Lafayette or Allied. Then there was the
adventure when I was building a CD ignition (not a common thing in the
late '60s) and needed some ferrite cores. My cousin knew a guy who knew a
guy... and I wound up at a garage operation in Kingston. IBM always had
their eye on monopoly investigations so the backwoods of NY were filled
with cottage operations they had spun off.
 

    Looking at building a small FM transmitter wired to my mail-box.
    Being right at the road, and a bit away, it's useless trying to do
    image-ID and there is no hope of getting power out there.

 Just for an alert? How far? I'd probably use a couple of Picos or even
Arduinos with nrf@$L01 modules.
 https://howtomechatronics.com/tutorials/arduino/arduino-wireless-
communication-nrf24l01-tutorial/
 and a PIR to detect when the box was opened.
 https://learn.adafruit.com/pir-passive-infrared-proximity-motion-sensor/
using-a-pir-w-arduino
 The receiver in the how could blink LEDs, buzz, or whatever. For real sex
you could use neopixels for a pulsating rainbow effect.
 https://www.adafruit.com/category/168

   Picos and friends require constant power input.
   Not possible.
   Pissed off ... LONG back you could have a PV cell
   device in 1/4" format that could produce about
   five volts. Might have been made for NASA. Can't
   find anything like that now.
   The idea of the PV is that it creates its OWN power.
   Anything else, CdS or whatever, requires constant
   power to work.
   DID kind a solve the 'rate change' detector ... it
   requires a cap and couple high-val resistors. If the
   cell sees positive change then it surges power, which
   gets through the cap. This is enough to trip a 'start'
   on the transmitter. Does not matter if the light was
   low or higher, the CHANGE is what the circuit transmits.
   If > 0.7 v .......
   Anyway, still looking for the right parts. May NOT
   really exist anymore alas. However any SMALL 5v
   PV array ... 1cm cells in a flat linear setup ...
   may still do the trick discretely.
   DID consider using the entire mailbox as a 'C' in
   a resonant circuit ... but RAIN would screw that up.
   It's really a kinda evil problem. Again, can't
   make any of the tech large/obvious ........