E3D PT-100 on RADDS configuration

Simme

Hi all,

can anyone help me with the PT-100 from E3D on RADDS board?

I have the amplifier board connected to the AUX-analog input (analog PIN 5), selected PT-100 for E3D in the configurator (EXT0_TEMPSENSOR_TYPE 13) and set the Pin to 5 (EXT0_TEMPSENSOR_PIN 5).

Now when I power on the printer (everything at room temp), it shows a temperature of 300°C on the hotend, rapidly increasing to 600°C until the watchdog stops and it just shows "def".

Any suggestions?

Cheers,

Simme

juulius

the pt100 board from E3D needs 5 volt to function, so the liniar graph from the board will be between the 0 - 5 volt.
Radds boards can only read 0-3.3 volt,so the ADC wil be scaled between 0 - 3,3 volt,
where the 8 bit controllers are scaling between 0-5 volt

Or you need to make your own Table from the datasheet from E3D. Note that 5 volt on a 3.3 board input wil shorten the life span of the input / controller

Or you need a other board that wil work with 3.3 volt. I was working on a way to make a MAX31865 (SPI pt100/pt1000 board) work with radds.. im still working but the board refuces to work with repetier because it uses a other SPI mode then what repetier uses.

currently im using semitec 104-GT2 sensors.

Simme

Hi, thanks for the answer.

I just tested the PT-100 and it seems to work flawless. According to the temperature table of E3D the board will deliver 3V at 500°C. I tested with a hot air gun set to 200°C heating the PT-100, and the board gave about 1.9V back. 

So with the expected temperature range it should not be a problem to power the board with 5V, as the received voltages are well below the 3V3 of the RADDS board.

Nevertheless, somehow the firmware does something strange with the input of Pin 5.

Maybe the read value of the voltage needs to be inverted? 

How can I set the firmware to invert the value?

Cheers,

Simme

Repetier

Temperatures are converted in Extruder.cpp

void TemperatureController::updateCurrentTemperature()

13 is a PTC so input is already inverted. It just follows the implemented temperature-adc curve.

Simme

Ooook, I just had a look at Extruder.cpp. 

I have to admit that I'm not into cpp, just had a few hobby projects in python so far. And I don't really understand a bit of what is written there and how it could possibly help me. 

Anyway I did some hardware test - when I connect the Aux ADC to GND it also shows 600°C and then def.

Then I connected 3V3 to ADC and it shows the same - 600°C and the def.

So it seems like I missed some step in my configuration to make sure that AUX ADC is checked. Any hints what I might have missed?

My changes to config.h were:

      - 2016-11-25, 14:24; #define EXT0_TEMPSENSOR_TYPE 13 (war 14), Umbau auf PT-100 am Hotend

      - 2016-11-25, 14:24; #define EXT0_TEMPSENSOR_PIN 5 (war: TEMP_0_PIN), Umbau auf PT-100 am Hotend

Do I need to change anything else?

Rossini

do you know http://doku.radds.org/thermocouple/

do you really use a RADDS and repetier firmware. i think your configs are for ramps with marlin.

Simme

You made my day!!

I just changed: #define EXT0_TEMPSENSOR_PIN THERMOCOUPLE_0_PIN

and now it works!

A huge thank you!

Simme

Rossini said:

do you know http://doku.radds.org/thermocouple/

do you really use a RADDS and repetier firmware. i think your configs are for ramps with marlin.

That was the hint I needed

And yes, I use Repetier on RADDS - the config.h is straight out of the online configuration tool.

Rossini

So did you just 

define EXT0_TEMPSENSOR_TYPE 13

and #define EXT0_TEMPSENSOR_PIN THERMOCOUPLE_0_PIN ?

On which voltage did you connect it? 3,3 or 5v?

I maybe get also a pt100. Thanks

Simme

Yes, just the two definitions as you said. I connected the supply for the PT100 Board to 5V - I measured before connecting and with 5V supply I don't receive voltages of 3V or higher on the signal line (heated up the sensor only with a controlled hot air gun to just above 300°C).
Only issue I have is that temp readings are somewhat unstable in the last days - like jumping 1-2 °C. Usual it was the digit after the decimal jumping a bit. Any Ideas?

Rossini

unstable 5v supply? Don't know.