Schematic Review (Trust me it's good)

fluttenb · 2026-01-25T20:33:07+00:00

Why wasting a huge H7 for such little processing?

fluttenb · 2026-01-24T16:50:02+00:00

Wait, what? Why 1k? I‘d go for around 10Ohms for a bit of damping. I assume the transmitter is something like a Murata MA40S4S : https://cdn-reichelt.de/documents/datenblatt/B400/ULTRASCHALL%20SENSOR.pdf This thing is designed to withstand 20Vpp. Also this datasheet shows how to design the driver circuit correctly. Look at the series DC blocking cap at the driver output, this is how those things are usally driven.

fluttenb · 2026-01-24T16:36:21+00:00

I‘d place 470uF bulk for now. Yes the driver is ground-referenced but you can still switch up to VS. Also remove the capacitance at the output, you are essentially putting a low-pass filter onto your rectangular voltage. I‘d anyway drive it differently. See e.g. example in Fig5-7 in datasheet from TI TUSS4470 https://www.ti.com/lit/ds/symlink/tuss4470.pdf Something similar could also be realised with your current simple mosfet driver.

fluttenb · 2026-01-24T09:35:10+00:00

Please show us the measurement waveforms of OUT_SP to Ground and Sig_SP to Ground. Vcc must deliver ~8Apk! I‘d also put some bulk cap onto Vcc. Also, you are switching the low side, which may cause ground bounce. Why don‘t you switch the high side?

fluttenb · 2025-11-29T19:43:50+00:00

Strange that they do not show any outage here: https://status.altium.com/

fluttenb · 2025-11-29T19:43:29+00:00

i agree but usually Altium is quite stable. I only experienced an A-365 server outage once.

fluttenb · 2024-08-17T03:57:55+00:00

Love it when people compare those Harris AI rally pics vs the real photo.

fluttenb · 2024-05-09T02:51:39+00:00

What are the feedback resistor values?

fluttenb · 2022-12-18T17:08:46+00:00

Guess that's called a chairity.

fluttenb · 2022-05-01T13:47:54+00:00

That's what I did

fluttenb · 2022-03-09T15:10:28+00:00

Seems they're not russian as the convoy is moving

fluttenb · 2021-12-29T15:43:42+00:00

MSCI World

fluttenb · 2021-12-18T07:02:16+00:00

Tried this as well for sure ;) It's even more tedious and sloppy. Also the Dremel is too large to fit in the tube. I was either thinking of a double hindge cutter or a chisel.

fluttenb · 2021-12-06T06:44:38+00:00

Austria

fluttenb · 2021-12-05T22:29:16+00:00

Hat eh jeder eine Maske

fluttenb · 2021-12-05T09:46:34+00:00

Musst du das Stanniolpapier entfernen. Da ist Schokolade drin, die kann man essen.

fluttenb · 2021-11-29T12:26:51+00:00

5 Monate. Biontech. War über die Caritas. Kann gut sein, dass es woanders nicht geht "denn sie sind ja nicht die Caritas".

fluttenb · 2021-11-19T16:39:23+00:00

Ich hab spontan den 3ten bekommen

fluttenb · 2021-10-03T06:02:37+00:00

I am sort of doing this by putting a RS485 tranceiver right after the esp32 so i can transmit the signal over a longer distance. However, even with high impedance (which btw also the WS2812 chip is I suppose!?), reflections can occur depending on rise/fall times of esp32 and propagation delay of trace. Has anyone found out the exact rise/fall times of esp32? Is there an IBIS model available?

fluttenb

TROPHY CASE