Filamentwidth sensor on MKS SBASE 1.3 problems

Forgot to mention : Marlin 2.0

I run filamentwidth sensor on my k8200 without problems, and now i want to run one on my delta which have
MKS SBASE1.3.

But i can't for my life understand how to confure it.
The sensor is modified for 3.3v output

I thought about using termpsensor 4 as input.
I changed in mks_pins tempsensor 4 to: #define FILWIDTH_PIN P0_26_A3 // A3 (TH4)
Enabled filamentwidthsensor in configuration_adv_h

But then what? I get "some" readings from the sensor , but they are in the range of 45-60mm.
I was thinkig that the tempsensor input has a pullup resistor? Turn it off? How?

And as the sensor is designed for 0-5v where 3v is 3.00mm, but as it is 0-3.3v now where do i recalculate (value*1.515)?

Edited 2 time(s). Last edit at 12/31/2019 06:18PM by AndersE.

Thermistor pins have a pull up resistor and a cap on the motherboard.

You need to de-solder these if you wish to use this pin.

R48 and C38 according to [github.com]

Really? aren't the pullups programmable? why then is it labeled thermistor_pullup in the code then?

Quote
AndersE
Really? aren't the pullups programmable? why then is it labeled thermistor_pullup in the code then?

It's the same with the SKR 1.3 pullups. They cannot be disabled in the firmware because they are hardwired. Some Chinese boards just weren't made with the end user in mind. However, I believe these manufacturers are actually listening to the users and are making changes now. For example for SKR 1.4 board has many improvements but I'm not sure if pullup resistors have been addressed yet. Anyway, good luck soldering, or find another set of free pins maybe. It should be doable. On my SKR 1.3 I could use the servo pins to program other functions for example.

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http://www.marinusdebeer.nl/

Did not help removing cap and resistor. still getting strange numbers.

with sensore disconnected vslues is around 75 (M407), sensor connected values around 35, with filament in sensor around 25.
so it changes when filament is run into it. but diameter 25mm is wrong

still think i have configured wrong or missed something.

Edited 2 time(s). Last edit at 01/02/2020 12:19PM by AndersE.