Set auto fan pins to RAMPS D8 pin

[diegotrap]

I have set the Configuration_adv.h parameters to be able to use the D8 (MOSFET) port in my RAMPS 1.4 to connect an extruder fan. This fan has to be ON whenever the hotend is working (typical case for an all metal extruder). These are the resulting lines of code:

#define EXTRUDER_0_AUTO_FAN_PIN 8 //RAMPS_D8_PIN
#define EXTRUDER_1_AUTO_FAN_PIN -1
#define EXTRUDER_2_AUTO_FAN_PIN -1
#define EXTRUDER_3_AUTO_FAN_PIN -1
#define EXTRUDER_AUTO_FAN_TEMPERATURE 5
#define EXTRUDER_AUTO_FAN_SPEED   255  // == full speed

This doesn't turn on the fan when the temperature is above 5ºC (always). I have tested it in both RAMPS_14_EFB and RAMPS_14_EFF pin maps.

I think the problem is that pin number 8 is already been used for the bed/other fan and this setting is overriden, but it should be a way to make it work. Many printers use a noisy hotend fan and it would be a great way to turn it off without disconnecting the whole printer.

[thinkyhead]

What version of Marlin are you using?

[diegotrap]

Marlin 1.10 RC7

On Thu, Aug 11, 2016 at 9:58 AM, Scott Lahteine notifications@github.com
wrote:

What version of Marlin are you using?

—
You are receiving this because you authored the thread.
Reply to this email directly, view it on GitHub
#4579 (comment),
or mute the thread
https://github.com/notifications/unsubscribe-auth/AEE56SUUpYolztKSlDxzqjoarAPTdZVXks5qetYagaJpZM4JgZ6a
.

[thinkyhead]

Do you experience the same issue with RCBugFix? I'm looking at the RAMPS pins now, and it seems that as long as you're using RAMPS_14_EFB, EEB, or EFF you should have no conflict. In fact, you ought to only have a conflict in the first 2 cases if you are also trying to use a heated bed.

Try with RCBugFix and if you still can't get it to work, post your Configuration.h and Configuration_adv.h so we can test-compile with them and figure out what's going on.

[boelle]

hmm... he might be on to something

one output cant rarely be tied to more than one pin in the pins file...

maybe test this theory by setting all FAN_PIN to -1

just a thought

[thinkyhead]

@boelle That's one way, but I have a technique to see exactly what's going on. I use the given config, and then I add pre-compiler code that checks the values of the pins I'm interested in. When I compile, I can see whether they are set to expected values or something else. If needed, I can add code to print out the values of all the pins at runtime.

[diegotrap]

I have upgraded to RCBugFix and tried again, the fan still doesn't turn on. I upload the Configuration.h and Configuration_adv.h as .txt so you can replicate this error and we can learn from it.

Thank you very much for your help, thinyhead.

Configuration_adv.txt
Configuration.txt

[thinkyhead]

Your configuration is good, and everything seems to be setting up correctly, so the checkExtruderAutoFans function is certainly being invoked. I'll test the auto-fan code on one of my printers in a little while, but in the meantime here's one thing you can try. In temperature.cpp change the code in the Temperature::init function that initializes EXTRUDER_0_AUTO_FAN_PIN to the following…

  #if HAS_AUTO_FAN_0
    #if EXTRUDER_0_AUTO_FAN_PIN == FAN1_PIN
      SET_OUTPUT(EXTRUDER_0_AUTO_FAN_PIN);
    #else
      pinMode(EXTRUDER_0_AUTO_FAN_PIN, OUTPUT);
    #endif
  #endif

[thinkyhead]

I just did a test of RCBugFix both with and without that change, and it seemed to work fine. As soon as the extruder reached the configured temperature the fan came on at full speed. When the temperature fell the fan turned off. As you do your testing, double-check to make sure the fan is connected to the correct plug, and that all the wiring is good.

[boelle]

@diegotrap had any chance to test this?

[diegotrap]

I have a fan connected with the right polarity to the D8 RAMPS pin. I have changed the fan, measured with a multimeter and there is no signal in that output.

Should I try all the new commits?

[diegotrap]

I have tested the latest version of RCBugFix, with the new commits related to the fans.

I still can't make it work. I have used two different RAMPS, checked all the hardware part and have not being able to get the fan to turn on.

Have you made it work with my same settings in a physical machine?