FEDEVEL
Platform forum

Alaeddine , 02-14-2025, 11:45 AM

Hi, i had my board designed and when i tested it with a multimeter i had different resistance values showing over these resistors when i pull the switch high. I guess i made a design mistake. are this resistor's placement correct like this or not ? Thanks in advance

QDrives , 02-14-2025, 08:45 PM

As in you measure the 12k resistor in parallel with everything that has a 'resistance' between +3.3V and Gnd? Of course.

QDrives , 02-14-2025, 09:31 PM

What do you measure?

Alaeddine , 02-15-2025, 08:08 AM

When i put the switch in Position 1 (+3V3) and check the continuity the resistor shorts so i measure 0 Ohm but when i switch to position 3(GND) i measure 0.3k then 0.5k then 1k.

QDrives , 02-15-2025, 12:56 PM

That is expected.
What is the 'resistance' of a capacitor?

Alaeddine , 02-16-2025, 10:54 AM

Open connection ?

QDrives , 02-16-2025, 08:07 PM

Is it?

If I just tell you, you do not learn and continue to ask.
Fedevel is on teaching.

But if a capacitor is just an "open connection", why would you place them? You could simply leave it open, right?

Robert Feranec , 02-17-2025, 07:55 AM

I would recomend you to redraw the circuit on paper (for every switch position you need), replace the switches with wires. Also add the circuit that is behind SS2,4,6,8 connections. You will then find out, that your circuit probably connects multiple resistors in parallel and in series and that is why you are getting these values.

Alaeddine , 02-17-2025, 09:37 PM

yes that's right the value i'm reading is approximately the total resistance of a 8 12k parallel resistors. So i need in this case to desolder them and correct them for a better design.

QDrives , 02-17-2025, 10:20 PM

They will be in parallel in the "better" design too.
But the question is, does the switch work to drive the voltages?