Gen7 - can't read thermistor values
Posted by 0kumy0
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Gen7 - can't read thermistor values December 17, 2011 12:36PM |
Registered: 12 years ago Posts: 7 |
Hi all,
I've finished my gen7 board a few days ago, and in the initials tests, I remember I could read Extruder temperature but the bed stay to 0°C.
Finally solved mechanicals problems, I've tried to use my new gen7 board.
The are two problem (maybe related each other
):
* Bed temp is always 0°C
* Extruder Temp reading when power supply is on is always : 279,5°C :/ (temp should be at around 20°C)...
(Focus on extruder problem)
What I've tried is:
* check thermistor value alone with ohmmeter -> 120k ohm
* check for shorts circuits
* measure voltage between GND / PIN A1 -> 0,21V
* measure voltage between PIN AREF / PIN A1 -> -4,95V
* measure voltage between GND / 5V -> 5,25V
If I remove the Atmega 644:
* measure voltage between GND / PIN A1 -> 5,04 V
* measure voltage between PIN AREF / PIN A1 -> 0V
* measure voltage between GND / 5V -> 5,25V
RT1/RT2 are 4,7k...
Any advice ?
Bests
I've finished my gen7 board a few days ago, and in the initials tests, I remember I could read Extruder temperature but the bed stay to 0°C.
Finally solved mechanicals problems, I've tried to use my new gen7 board.
The are two problem (maybe related each other
):* Bed temp is always 0°C
* Extruder Temp reading when power supply is on is always : 279,5°C :/ (temp should be at around 20°C)...
(Focus on extruder problem)
What I've tried is:
* check thermistor value alone with ohmmeter -> 120k ohm
* check for shorts circuits
* measure voltage between GND / PIN A1 -> 0,21V
* measure voltage between PIN AREF / PIN A1 -> -4,95V
* measure voltage between GND / 5V -> 5,25V
If I remove the Atmega 644:
* measure voltage between GND / PIN A1 -> 5,04 V
* measure voltage between PIN AREF / PIN A1 -> 0V
* measure voltage between GND / 5V -> 5,25V
RT1/RT2 are 4,7k...
Any advice ?
Bests
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Re: Gen7 - can't read thermistor values December 17, 2011 06:32PM |
Registered: 12 years ago Posts: 7 |
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Re: Gen7 - can't read thermistor values December 18, 2011 03:06AM |
Admin Registered: 17 years ago Posts: 7,881 |
The most common reason for the analogue inputs being broken is if they get shorted to 12V via the heater. I.e. a short in the hot end. That is consistent with the extruder temp reading high.
[www.hydraraptor.blogspot.com]
[www.hydraraptor.blogspot.com]
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Re: Gen7 - can't read thermistor values December 18, 2011 07:04AM |
Registered: 12 years ago Posts: 7 |
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Re: Gen7 - can't read thermistor values December 20, 2011 04:30PM |
Hello,
I am experiencing exactly the same issue. Double checked all my connections, no shorts.
Same voltages recorded as well.
But!
When I disconnect the ATX-20pin, jumper it on (green to black) I get a functioning temp sensor with the following voltages:
* measure voltage between GND / PIN A1 -> 4.97V
* measure voltage between PIN AREF / PIN A1 -> -0.19V
* measure voltage between GND / 5V -> 5.25V
Perhaps we have both made the same mistake. Try disconnecting the ATX plug and running with only the Molex diskette connections for power.
I am experiencing exactly the same issue. Double checked all my connections, no shorts.
Same voltages recorded as well.
But!
When I disconnect the ATX-20pin, jumper it on (green to black) I get a functioning temp sensor with the following voltages:
* measure voltage between GND / PIN A1 -> 4.97V
* measure voltage between PIN AREF / PIN A1 -> -0.19V
* measure voltage between GND / 5V -> 5.25V
Perhaps we have both made the same mistake. Try disconnecting the ATX plug and running with only the Molex diskette connections for power.
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Re: Gen7 - can't read thermistor values December 21, 2011 01:51PM |
Registered: 12 years ago Posts: 7 |
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Re: Gen7 - can't read thermistor values December 22, 2011 03:46AM |
Registered: 14 years ago Posts: 7,616 |
Quote
When I disconnect the ATX-20pin, jumper it on (green to black) I get a functioning temp sensor
Could you please try to find the reason for this? The 5V lines on the ATX20 are exactly the same as the ones on the 4 pin plugs. You obviously have a short somewhere.
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Re: Gen7 - can't read thermistor values January 10, 2012 02:14PM |
Don't want to thread-jack 0kumy0's thread, but I have yet to find the source of my thermistor issues.
I have double-checked all the traces and soldier points, both visually and with a meter. Nothing that I found.
I wonder if the cause is from my old, and extremely cheap 300 watt off-brand PSU. Possibly an internal ground issue or difference?
I'll have to get a trusted PSU and try again.
I have double-checked all the traces and soldier points, both visually and with a meter. Nothing that I found.
I wonder if the cause is from my old, and extremely cheap 300 watt off-brand PSU. Possibly an internal ground issue or difference?
I'll have to get a trusted PSU and try again.
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Re: Gen7 - can't read thermistor values January 11, 2012 08:09AM |
Registered: 14 years ago Posts: 7,616 |
Did you know Gen7's temperature readout works when the PSU is turned on, only? With Teacup firmware, switching on the heater also turns on the PSU and thus thermistor readings.
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Re: Gen7 - can't read thermistor values January 11, 2012 09:02AM |
Registered: 12 years ago Posts: 7 |
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Re: Gen7 - can't read thermistor values January 13, 2012 10:37PM |
Registered: 13 years ago Posts: 632 |
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Re: Gen7 - can't read thermistor values January 29, 2012 11:14AM |
Registered: 12 years ago Posts: 7 |
hi,
chip received. Now it works
Be the way I'm testing repetier-firmware / host. It is quiet cool, except that I can't make it slice with skeinforge... (related thread)
Thanks for pointing me to the right direction.
chip received. Now it works
Be the way I'm testing repetier-firmware / host. It is quiet cool, except that I can't make it slice with skeinforge... (related thread)
Thanks for pointing me to the right direction.
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Re: Gen7 - can't read thermistor values June 12, 2012 09:17PM |
Hi,
I'm just finishing my Gen7 1.3.1 ATmega 644 20 Mhz printer and uploaded Teacup with no error messages . Everything looks fine with the sttepers and I can move all of them, but I am facing some problems with the temp sensor and heaters.
I used the config file in the GIT repository and defined the temp sensor at PINA1 and PINA2. Heaters on DIO3 and DIO4. Compiling the fimware with this definition, the Pronterface can't connect the printer. If I comment out the temp sensor defintion, recompile and reload Teacup, them the connection is succesufull but without any response from the thermistors or the heaters.
Any suggestion in how solve this?
Thanks for any help!
Enobrega
I'm just finishing my Gen7 1.3.1 ATmega 644 20 Mhz printer and uploaded Teacup with no error messages . Everything looks fine with the sttepers and I can move all of them, but I am facing some problems with the temp sensor and heaters.
I used the config file in the GIT repository and defined the temp sensor at PINA1 and PINA2. Heaters on DIO3 and DIO4. Compiling the fimware with this definition, the Pronterface can't connect the printer. If I comment out the temp sensor defintion, recompile and reload Teacup, them the connection is succesufull but without any response from the thermistors or the heaters.
Any suggestion in how solve this?
Thanks for any help!
Enobrega
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Re: Gen7 - can't read thermistor values June 13, 2012 03:41AM |
Registered: 14 years ago Posts: 7,616 |
On v1.3.1, thermistor readouts require the power supply to be running. So, to get a readout, set the temperature to below room temperature: M104 S5 to keep the PSU alive.
On why Pronterface doesn't dectect "connected": I always wondered what this "connected" should be. Looking at what G-code Pronterface sends to the printer and what comes back should help.
On why Pronterface doesn't dectect "connected": I always wondered what this "connected" should be. Looking at what G-code Pronterface sends to the printer and what comes back should help.
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Re: Gen7 - can't read thermistor values June 13, 2012 05:41AM |
Thanks Traumflug.
i will try set the temperature below room to see the results.
Pronterface doesn't get connection means: if I keep the temp sensors and heaters at PINA1/PINA2 and DIO3/DIO4 , launch and hit the "connect" button at Pronterface, I'm getting as response a " connecting ......" but never get the connection between the Pronterface and the printer!
In the other hande, if a comment out th sensors definition in config.h and reload Teacup, them the Pronterface connection happens normally.
Could I have some problem with my pin definition?
Tks.
i will try set the temperature below room to see the results.
Pronterface doesn't get connection means: if I keep the temp sensors and heaters at PINA1/PINA2 and DIO3/DIO4 , launch and hit the "connect" button at Pronterface, I'm getting as response a " connecting ......" but never get the connection between the Pronterface and the printer!
In the other hande, if a comment out th sensors definition in config.h and reload Teacup, them the Pronterface connection happens normally.
Could I have some problem with my pin definition?
Tks.
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Re: Gen7 - can't read thermistor values June 14, 2012 01:29AM |
Registered: 14 years ago Posts: 7,616 |
Please look at which G-code is sent and what answers come back. This GUI stuff isn't helpful for debugging.
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Re: Gen7 - can't read thermistor values June 15, 2012 10:33PM |
Trying through Arduino monitor. If I keep the Temp_Sensor definition as it is in the Config.H, simply ther is no connection with the printer (no response at all !). Commented out the Temp_Sensor definition, then I have communication!
The M105 is giving back T:0 and B:0.
I can switch on the heaters but withou feedback from the sensors.
I am still thincking there is some problem with pin definiton.
I am using PINA1 and PINA2 for the extruder and bed.
Any suggestion?
Tks
The M105 is giving back T:0 and B:0.
I can switch on the heaters but withou feedback from the sensors.
I am still thincking there is some problem with pin definiton.
I am using PINA1 and PINA2 for the extruder and bed.
Any suggestion?
Tks
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Re: Gen7 - can't read thermistor values June 16, 2012 09:27PM |
I decided to start to take some measurements on ATmega pins. You know what? When I took between AVCC and AREF I read 2,6V and this voltage quickily drop down to zero (while my multimeter was there!), then I got connection with Pronterface, the thermistor run and evrything was fine.
What is your suggestion?
maybe the 100uF coil would be the problem (to much noise on AREF) !!
Thanks
What is your suggestion?
maybe the 100uF coil would be the problem (to much noise on AREF) !!
Thanks
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Re: Gen7 - can't read thermistor values June 17, 2012 04:51AM |
Registered: 14 years ago Posts: 7,616 |
This coil is there to reduce the noise ...
AVCC and AREF are both 5V, so a difference of 0V is expected. I'd try to find out why it takes so long (longer than a 1/10 of a second) to make them equal. Missing connection, bad solder junction somewhere?
AVCC and AREF are both 5V, so a difference of 0V is expected. I'd try to find out why it takes so long (longer than a 1/10 of a second) to make them equal. Missing connection, bad solder junction somewhere?
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Re: Gen7 - can't read thermistor values June 17, 2012 05:28PM |
Admin Registered: 17 years ago Posts: 7,881 |
A " 100uF coil" would definitely be a problem. Inductance is measured in Henrys and capacitance in Farads, so if if is indeed a 100uF capacitor instead of an 100uH inductor it would give exactly the symptoms you describe.
[www.hydraraptor.blogspot.com]
[www.hydraraptor.blogspot.com]
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Re: Gen7 - can't read thermistor values June 17, 2012 08:42PM |
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Re: Gen7 - can't read thermistor values June 24, 2012 09:21PM |
Just an update! The inductor was the problem! Changed to a new one and got connection with Pronterface!
Due some aviability I installed an 200 uH inductor instead of an 100uH. Any problem on that?
Another help!
The printer is working fine but, for some reason, after around 5 minutes printing the PSU shut off.
The Pronterface keep running but the printer stop!
To restart the printer I need to hard reset the board and connect it again at Pronterface.
I can immediately start to print again but, after 5 minutes stop! This behaviour happens everytime!
Any thoughts?
Thanks
Due some aviability I installed an 200 uH inductor instead of an 100uH. Any problem on that?
Another help!
The printer is working fine but, for some reason, after around 5 minutes printing the PSU shut off.
The Pronterface keep running but the printer stop!
To restart the printer I need to hard reset the board and connect it again at Pronterface.
I can immediately start to print again but, after 5 minutes stop! This behaviour happens everytime!
Any thoughts?
Thanks
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Re: Gen7 - can't read thermistor values June 26, 2012 07:39AM |
Registered: 14 years ago Posts: 7,616 |
Automatic PSU off is controlled by the variable psu_timeout in clock_250ms() in clock.c. psu_timeout should be reset to zero on every stepper step, see dda_step() in dda.c. The timeout is set to 30 seconds, so this 5 minute thing might be something else. Also, the PSU shouldn't turn off as long as a heater is set to something above zero.
Do you use absolute or relative E commands? Absolute E is currently limited in Teacup, so you might get better results with relative E. Switching from absolute E to relative E is a change in the G-code compiler ( = slic3r, Skeinforge, ...) and mayba also a matter ov E_ABSOLUTE in config.h in case the G-code compiler doesn't support M82/M83.
Do you use absolute or relative E commands? Absolute E is currently limited in Teacup, so you might get better results with relative E. Switching from absolute E to relative E is a change in the G-code compiler ( = slic3r, Skeinforge, ...) and mayba also a matter ov E_ABSOLUTE in config.h in case the G-code compiler doesn't support M82/M83.
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Enobrega
Re: Gen7 - can't read thermistor values June 26, 2012 09:11PM |
I'm using E absolute. I will try with relative to see if there is any change.
Just an update .... after many tries with Teacup and Pronterface, without good results due this unexpected PSU shut off, I decided to try Repetier firmware and host.
Beleive or not, without any change in the config file ( only board and thermistor selection) the printer start to run and I was able to,print a couple of calibration cubes, without this unexpected PSU shut off.
maybe I made some mistake in Teacup config file so, I will double check everything and try with E Relative in the compiler.
I will let you know the results.
Thanks for your support.
Just an update .... after many tries with Teacup and Pronterface, without good results due this unexpected PSU shut off, I decided to try Repetier firmware and host.
Beleive or not, without any change in the config file ( only board and thermistor selection) the printer start to run and I was able to,print a couple of calibration cubes, without this unexpected PSU shut off.
maybe I made some mistake in Teacup config file so, I will double check everything and try with E Relative in the compiler.
I will let you know the results.
Thanks for your support.
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Re: Gen7 - can't read thermistor values July 01, 2012 05:17AM |
No diffent results with E relative In Teacup config.h ! Still an unexpected PSU shut off in middle of the printer job.
Same behaviour with ! Less frequency but still there !
Double and triple check the soldering and seems everything is ok with the board!
Maybe some protection parameters which is turning off the PSU to protect the eletronics!
Any additional suggestion?
Regards
Same behaviour with ! Less frequency but still there !
Double and triple check the soldering and seems everything is ok with the board!
Maybe some protection parameters which is turning off the PSU to protect the eletronics!
Any additional suggestion?
Regards
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Re: Gen7 - can't read thermistor values July 01, 2012 06:07PM |
Registered: 14 years ago Posts: 7,616 |
OK, let's start debugging.
There's a file pinio.c and in line 23 the function power_off() starts. Put these two lines right at the beginning, at line 24, into this function:
Then the firmware will report back when it turns off the PSU. If there is no such message sent when the PSU turns off, the reason is likely not in software.
Another thing is, your electronics might see an unwanted reset. Does the "start" message appear after the PSU off?
Third idea (it's sunday today): is it possible you double-configured a pin? Use an text editor's search function to look out for another use of the pin's name.
There's a file pinio.c and in line 23 the function power_off() starts. Put these two lines right at the beginning, at line 24, into this function:
#include "sersendf.h"
sersendf_P(PSTR("power_off()"));
Then the firmware will report back when it turns off the PSU. If there is no such message sent when the PSU turns off, the reason is likely not in software.
Another thing is, your electronics might see an unwanted reset. Does the "start" message appear after the PSU off?
Third idea (it's sunday today): is it possible you double-configured a pin? Use an text editor's search function to look out for another use of the pin's name.
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Re: Gen7 - can't read thermistor values July 10, 2012 10:31PM |
Registered: 12 years ago Posts: 10 |
Seems the problem is not in the software!
I rebuilt the ground wire on the board, following your instruction for Gen 7 V1.2, and I got much better results on the printer stability.
One ground circuit for the heaters and another one for the ATmega.
After this change, I was able to print several jobs, with just one unexpected PSU shut off.
I still need to go deeper to solve it completely and, seems to me, the problem is related to some interference.
I will keep you informed.
Anyway, thanks for your support.
I rebuilt the ground wire on the board, following your instruction for Gen 7 V1.2, and I got much better results on the printer stability.
One ground circuit for the heaters and another one for the ATmega.
After this change, I was able to print several jobs, with just one unexpected PSU shut off.
I still need to go deeper to solve it completely and, seems to me, the problem is related to some interference.
I will keep you informed.
Anyway, thanks for your support.
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Re: Gen7 - can't read thermistor values August 05, 2012 09:24AM |
Registered: 17 years ago Posts: 137 |
Regarding thermistor readings ....
What would be the symptom(s) of a broken analog input pin?
I have my Teacup firmware configured to read the extruder temperature on PA1 (the default), and am using the standard ECOPS thermistor that comes with the J Head hot-end. The resistance of the thermistor itself seems to be changing as expected, but the voltage on PA1 is staying at around 5 V (i.e. the voltage is being held high even though the resistance of the thermistor is dropping).
Also, the resistance between PA1 and Vcc is about 4.5 Kohm. Does this signal a broken pin?
What would be the symptom(s) of a broken analog input pin?
I have my Teacup firmware configured to read the extruder temperature on PA1 (the default), and am using the standard ECOPS thermistor that comes with the J Head hot-end. The resistance of the thermistor itself seems to be changing as expected, but the voltage on PA1 is staying at around 5 V (i.e. the voltage is being held high even though the resistance of the thermistor is dropping).
Also, the resistance between PA1 and Vcc is about 4.5 Kohm. Does this signal a broken pin?
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Re: Gen7 - can't read thermistor values August 06, 2012 05:51AM |
Registered: 14 years ago Posts: 7,616 |
Quote
Also, the resistance between PA1 and Vcc is about 4.5 Kohm.
That's expected, it's the value of resistor RT2 (4.7 kOhms).
What does the other thermistor input say? Both inputs are identical.
Also make sure the configuration is right. IIRC, "PA1" doesn't work in Teacup's config.h, "PINA1" does. For whatever reasons
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Re: Gen7 - can't read thermistor values August 06, 2012 02:39PM |
Registered: 17 years ago Posts: 137 |
Thanks Markus. I changed the firmware parameters to use PINA2 instead of PINA1 for the extruder thermistor - which is an option because I'm not using the heated bed right now - and it seems to be working a lot better now. (I noticed one or two funny things which I might elaborate on later though.) Obviously I'll try to investigate why the default pin isn't working if time permits.
As an aside ...
Is there somewhere in the Teacup configuration files to change the PID settings? At the moment I'm getting fairly large fluctuations about the temperature set-point.
(Edit: Just found a reference to the M130-M134 commands in 'gcode_process.c'. Will test these and maybe follow up if needs be.)
Edited 1 time(s). Last edit at 08/06/2012 05:31PM by dslc.
As an aside ...
Is there somewhere in the Teacup configuration files to change the PID settings? At the moment I'm getting fairly large fluctuations about the temperature set-point.
(Edit: Just found a reference to the M130-M134 commands in 'gcode_process.c'. Will test these and maybe follow up if needs be.)
Edited 1 time(s). Last edit at 08/06/2012 05:31PM by dslc.
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