Category Archives: tECHNOLOGY

Heffley house air conditioning



Manual for the oitside unit.


Large difference in the shape of the curves after cleaning the filters.  Right side of the screen is running filters removed.

July 22 2023, typical 103 degree day, no filters installed.



29×10.   19.5×19.5








Read a 90 ohm propane tank level meter and turn on an LED

This code uses a Atiny85 under Arduino gui:


#include <avr/sleep.h>

const int inputPin = 2; // replace with the input pin connected to the voltage divider
const int outputPin = 3; // replace with the output pin connected to the load

void setup() {
pinMode(inputPin, INPUT);
pinMode(outputPin, OUTPUT);
digitalWrite(outputPin, HIGH); // ensure the load is not grounded initially

void loop() {
// Measure voltage on input pin
float voltage = analogRead(inputPin) * 0.0049; // convert from ADC value to voltage

// If voltage is below 2V, ground the output pin and go into deep sleep
if (voltage < 2.0) {
digitalWrite(outputPin, LOW);
delay(100); // ensure the load is fully grounded before sleeping

// Sleep for 1 day
delay(86400000); // 24 * 60 * 60 * 1000 = 1 day


Want to develop a product? Be careful what you wish for.

This via Tom Lancaster, (Deceased 2023, God rest his soul)

I might get dinged for re-post, but I often recommend these two gems, so I want them together where  i can refer people to them.

Ideas are like belly buttons.   Everyone has one, no one knows what to do with it.

You are not an inventor:


Patents are for PATENT LAWYERS…..   not developers (note this is a large collection of papers):

newpats_220813_154931 (1)


Here is a excerpt outlining a POSSIBLY successful path


I just got a helpline call from an
“inventor” trying to “protect” a
“new” auto headlight idea. To
stop “Detroit” from stealing it.
I’ve never heard of “Detroit” ever
paying any outsider for any untested,
undeveloped, or unproven idea.
Instead, “Detroit” buys parts from
suppliers and bolts them together to
make cars. They are in the process of
outsourcing much of their product
engineering. They are significantly
reducing their number of suppliers.
And holding them to the tightest of
razor thin margins.
Uh, strike one.
Illumination engineering is one of
the very few things that Fortune 500
companies happen to do very well. A
multi-skill project team approach is
usually required, combined with ray
tracing computers, arcane production
engineering, and outstanding access
to the world’s research base.
So, those big boys clearly have an
unbeatable home turf advantage here.
For strike two.
Your really big issue on all future
headlights is efficiency. Because of
downsizing in general and electric or
hybrid cars in particular. Anything
less than 100 Lumens per Watt won’t
hack it. You can bet that tomorrow’s
headlights will most definitely not be
based on a heated filament.
I got the impression the caller was
not a member of the SAE. Nor the
IESNA. Nor did he seem to be at all
into trade journals or online literacy.
He seemed to feel that car headlamp
efficiency was “not important.” And
apparently did not have the slightest
idea how woefully inefficient his new
design was. For a self-inflicted swing
and a miss for strike three.
A Realistic Alternative
Let us assume that you genuinely
feel that you do have a great “new”
headlamp design. What could you do
that works out in the real world? Step
one is to get yourself trade journal,
association, and online literate. To
make sure you aren’t talking about a
product that’s been sold for decades.
Or one that long ago fell off the shelf
because of inherent problems.
Step two is to ask yourself “Who is
it that (A) likes bright headlights, and
(B) has their own wallet in their own
back pocket?
Well, out here on my sand dune,
the answer is glaringly obvious: 4WD
desert off-roaders. To these folks, a
“map” light is 50,000 candelpower.
And a “running” light can vaporize
troublesome boulders at 75 paces.
On low beam.
So, firstoff, you would have a few
four wheelers critique your design. If
it is any good, you then let the local
4WD club beta test it. Once you have
your tested and proven product well
received, you sell a few at regional
meets. Then you publish it in all the
offroad mags.
Next you seek out one or more of
those off road lighting outfits. K.C.
Manufacturing is but one of the name
brand biggies out here. Competitors
include Dick Cepek, Hella, Explorer,
and Piaa corp.
But be sure to remember the key
insider secret rule for all successful
new product development: They must
come to you. And never vice versa.
Do note that you are not selling an
idea. Ideas are worth ten cents a bale
in ten bale lots. You are instead now
offering a proven, in-demand, and a
ready to manufacture product. here
you have already completed most of
the high risk steps.
More on becoming a purveyor of
risk reduction in RISKDOWN.PDF on And much more in
general on idea development in my
Blatant Opportunist and my Case
Against Patents package




Champ Camera

The great Robby Rhoades referes to this a s a checkup cam.


That way you can check up on yourself and see if you are having enough fun.



Early Camera Pan2

Audi is still picking up remote mic and internal mic.  Ill try to open the camera and remove the internal mic, and  solder a 1000 ohm resistor across the pads