On Sat, 25 Oct 2025 16:37:30 GMT, Jan Panteltje <
alien@comet.invalid>
wrote:
john larkin <jl@glen--canyon.com>wrote:
On Sat, 25 Oct 2025 07:23:03 GMT, Jan Panteltje <alien@comet.invalid> >>wrote:
john larkin <jl@glen--canyon.com>wrote:
Seems like every time I make some brilliant waveform and take a >>>>picture of its magnificence, what people notice is fingerprints on the >>>>screen.
https://www.dropbox.com/scl/fi/gu8hx6fkvu027wo6egsai/First_Light_DDG.jpg?rlkey=qnubwbcs0jcbopwi0pe3y19tp&raw=1
The other problem with pics is that one only notices dust and flux and >>>>crud too late.
Get a better camera?
I need a phone with a Windex sprayer. Or a scope with windshield
wipers.
I learned something about cleaning recently, I 'cleaned' my Polaroid sun glasses.
Those were cool for driving in the early morning with the sun low and in your eyes.
But after cleaning it I hardly could see anything..
Seems you need to be very careful cleaning polarized glasses...
Just bought new ones, tested it out yesterday, works OK.
bol.com/nl/nl/p/kingseven-piloten-zonnebril-unisex-uv400-gepolariseerd-zwart-zwart/9300000007802507/
At least this one came with a special cleaning cloth.
My Xiaomi smartphone camera is very good.
My Canon cameras too.
My Samsung phone is awful, but it has great cameras.
To spot fingerprints when taking the pictures the big smartphone screen is bettor than the small camera screens.
It sure didn't help testing this, when my intern left one of my scope >>>>channels set to "invert."
https://i.pinimg.com/736x/e4/8d/45/e48d45f1ea3f0f7e16396cbdb4c1579d--fingerprints-patterns.jpg
Which one is yours?
The fingerprints on my screen? Don't know. It's not a touch screen. I >>suppose some interns may be primates.
Yea...
The waveforms are mine. I was maybe a little critical of the FPGA
designers until I figured out that one signal was inverted. Well, they
made mistakes too. The best button on that scope is DEFAULT.
FPGA design discipline is another topic.
I'm making a delay generator from a triggered oscillator and a
counter, and that's the first light.
Have not done much with FPGA for a few years now.
Most simple multitasking things can be done with some Microchip 18F14K22 as long as it does
not have to be super fast.
OTOH there are very cheap FPGA boards on ebay.
That proto board has an RP2040 Pi cpu and an efinix T20 FPGA. The pi
configures the FPGA and then talks SPI to registers inside.
https://www.dropbox.com/scl/fi/npkdfdb4shr2m2jokqa1l/X116_On_Plate.jpg?rlkey=negw6radsojplh0zso6gha2vb&raw=1
It's running a DDS frequency synthesizer at 204 MHz, four 32-bit PRBS
trash generators, and the 50 MHz delay generator. I'm seeing zero
crosstalk jitter and the core is using 24 mA at 1.2 volts.
That's fabulous for $10. I don't program the parts myself; I
whiteboard the logic and let some kid code the VHDL.
FPGA culture is more like software than hardware. When we design a
multilayer PCB with hundreds of parts, we are super careful and review
it hard, because iterations are slow and expensive. Rev A always
works.
Coders type fast and let the compiler find typos and silly mistakes.
Once it compiles, they turn it over to the hardware guys to find
mistakes. They have no incentive to be careful.
Sadly, FPGA design usually follows the software methodology. Let the
users check your work.
John Larkin
Highland Tech Glen Canyon Design Center
Lunatic Fringe Electronics
--- PyGate Linux v1.5
* Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)
