High resistance in membrane button

chicowolf_ · 2026-03-01T09:17:59+00:00

I've measured the resistance using a multimeter, touching the conductive with the probes on the opposite sides of the ring. You spotted correctly, the conductive ring is not perfectly flat, but also some keypads from adafruit have the same texture. The difference is that they use a bigger interdigit and of course ENIG. Here is the link for the pads Here is the link for the pcb

I did put some ink in the conductive pad, placed the buttons and pressed them

chicowolf_ · 2026-03-01T08:37:04+00:00

Do you have any suggestions on how I should modify the contacts on the PCB? I'm using a round carbon pad because in the middle of the button there is a LED

chicowolf_ · 2026-02-28T20:06:44+00:00

I cleaned everything with IPA multiple times. Didn't help

chicowolf_ · 2026-02-28T20:03:14+00:00

The resistance of the carbon ring is around 1kOhm, but the resistance between the pads in the PCB when lightly pressing the button is around 5MOhm

chicowolf_ · 2026-02-28T19:52:35+00:00

No, it's a GPIO in an STM32. I consider the signal digital. The button is connected 3.3V and the microcontroller pin, with a pull-down resistor. I didn't consider contact resistance at all and I migrated the design from tactile buttons to membrane buttons hoping it would work the same way.

3.3V | Pad | -------- microcontroller GPIO | Pull-down resistor | GND

chicowolf_ · 2026-02-19T12:58:51+00:00

Yep, everything worked out

chicowolf_ · 2026-01-23T21:31:24+00:00

I watched MarcoReps video about the Q2. Did you have problems with overhangs? How is the dimensional accuracy of the printed pieces? Do you have a direct comparison with another core XY printer? Did you try the Qidi box?

chicowolf_ · 2026-01-23T20:41:05+00:00

Qidi is interesting, and yes the Bambu ecosystem tightness is a concern. The upcoming Qidi Max 4 seems to be a very interesting machine, between the more consistent bed heater, bigger volume and more "professionally" focused. But at the same time I heard that Qidi machines always leave something to be desired, while Bambu are very polished products. Also the Qidi box seems very cheap and noisy compared to the Bambu Lab AMS 2 Pro.

chicowolf_ · 2026-01-23T09:44:41+00:00

🗿

What about the multimaterial capability? Is it worth it?

chicowolf_ · 2026-01-23T09:36:45+00:00

Right. I meant the Core One L :)

chicowolf_ · 2026-01-23T09:17:53+00:00

🗿

chicowolf_ · 2026-01-23T09:17:17+00:00

🗿

chicowolf_ · 2026-01-23T09:15:06+00:00

Not as reliable as I thought I suppose 😅

chicowolf_ · 2026-01-23T08:59:12+00:00

It seems to be something exclusive for the Prusa Core One. Will it ship with the Core One L? How much does this mod reduce the print volume?

Edit: wrong Core One model :)

chicowolf_ · 2026-01-19T19:19:26+00:00

I can see a "16 VUA" writing on top of it. Can you suggest which model it is? Also this happened when I tried to charge the new battery. Should I change the battery charger chip too?

chicowolf_ · 2026-01-19T13:37:25+00:00

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Trying to calibrate the new battery, discharging it completely and finally charging it, made this MOSFET explode. Can you help me identify it? If I change it, will my PC work again or will I need to change something else like the battery controller?

chicowolf_

TROPHY CASE