Thermistor not being read

Hi All,

I'm finally setting this up and have found a problem with the Thermistor. Actually according to the troubleshooting, it's a problem with the Duet as it still reads nothing even when there is a 100k or 1k or 47k resistor accross the Thermistor pins.

Can anyone think of any more diagnostics i can run as i'm REALLY REALLY hoping it's not the board, cause it was working fine.
Thermistor reads bang on (for the ambient temp) from a direct reading on the heads by the board (when disconnected) so a break is unlikely.

M105 gets me:
T:B: 15.0
(I just noticed it doesn't say 'ok' could this be the problem?)

Thanks all
P

Edited 1 time(s). Last edit at 01/17/2015 12:51AM by parper101.

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Green Machine - slowly becoming multicoulored!

The only other test you can do is to check the wiring isn't shorting out. However the reprap guys are really good and i have seen comments that if the board is faulty they will replace it

If you are using Arduino serial monitor and it does not say OK, that suggests that config.g on the SD card is not being read at startup. That in turn means that the hot end is not being defined as a tool, which is why no temperature is returned for it.

Try sending M503 to see if config.g can be read at all.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

Quote
dc42
Try sending M503 to see if config.g can be read at all.

I send M503 and receive the following, which is my config.g card... it's perhaps just not being read properly?:

RepRapFirmware is up and running.

:THIS FILE IS ON YOUR MACHINE JAN16_2015
; Configuration file for RepRap Ormerod 1
; RepRapPro Ltd
;
; Copy this file to config.g if you have an Ormerod 1
; If you are updating a config.g that you already have you
; may wish to go through it and this file checking what you
; want to keep from your old file.
;
M111 S0 ; Debug off
M540 P0xBE:0xEF:0xDE:0xAD:0xFE:0xED ; MAC Address
M552 P192.168.1.111; ; IP address
M553 P255.255.255.0; ; Netmask
M554 P192.168.1.254; ; Gateway
M555 P2 ; Set output to look like Marlin
G21 ; Work in millimetres
G90 ; Send absolute corrdinates...
M83 ; ...but relative extruder moves
M558 P1 ; Turn Z Probe on
M906 X800 Y1000 Z800 E800 ; Set motor currents (mA)
;M305 P0 R4700 ; Set the heated bed thermistor series resistor to 4K7
;M305 P1 R4700 ; Set the hot end thermistor series resistor to 4K7
M92 E420 ; Set extruder steps per mm
M558 P1 ; Use an unmodulated Z probe
G31 Z0.8 P600 ; Set the probe height and threshold (deliberately too high to avoid bed crashes on initial setup)
M557 P0 X45 Y0 ; Four...
M557 P1 X45 Y190 ; ...probe points...
M557 P2 X215 Y190 ; ...for bed...
M557 P3 X215 Y0 ; ...levelling
M556 S78 X0 Y0 Z0 ; Put your axis compensation here
M201 X500 Y500 Z15 E500 ; Accelerations (mm/s^2)
M203 X15000 Y15000 Z100 E3600 ; Maximum speeds (mm/min)
M566 X1200 Y1200 Z30 E1200 ; Minimum speeds mm/minute
M563 P1 D0 H1 ; Define tool 1
G10 P1 S-273 R-273 ; Set tool 1 operating and standby temperatures

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Green Machine - slowly becoming multicoulored!

It could be that config.g is not being read at startup. Try sending M563 P1 D0 H1 via the serial monitor, and then see if you get a temperature reading for the hot end when you send M105.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

Ok, that's great! I do get a reading when sending the query directly (still no 'ok'):
T:3.7 B: 16.1

The second temp is about right, the first seems way off but that may be something to do with the card not being read. I've been through the troubleshooting for what to do if the sd card isn't being read section and maybe i'm daft, but i still can't seem to get it to read the SD card. Maybe i should try some isopropyl alcohol on the card to see if that will clean the contacts.

Now onto the next problem ! ....the SD card...
Thanks for your help (again) DC

P

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Green Machine - slowly becoming multicoulored!

If you send M555 P2 then you will get the OK as well.

The SD cards shipped with the original Ormerod 1 were problematic. Some could not be read by the Duet at all, some could not be read at startup but could be read later using M503 (I had one of those). The fix is to replace the SD card. RRP seem to think that class 4 cards should be OK, but if in doubt get a class 10. Get one with a low capacity, e.g. 4Gb.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

I have replace the SD card once already with an 8gb C8, so that shouldn't be the problem.
Yep, i got the 'ok' when sending M555 P2.

er... now what? How do i get it to read on startup??
The card is fine, it can be read fine, it's just not being read on startup, so it's kind of broken.

Anyone have any thoughts as to how i should proceed?

Thanks,
P

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Green Machine - slowly becoming multicoulored!

Which firmware version are you running?

PS - you may find that it doesn't read config.g on power up, but it does if you press the reset button.

It might be worth reformatting the SD card.

Edited 2 time(s). Last edit at 01/17/2015 08:12PM by dc42.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

I'm using:
FIRMWARE_NAME:RepRapFirmware FIRMWARE_VERSION:0.78c ELECTRONICSuet + Extension DATE:2014-09-18

....which i just downloaded yestrday. I suppose i'll have to try reformatting, and cleaning the heads. Seems odd to have to buy a new SD card every few months. When i hit the reset button i get the same dodgy error with no thermistor reading.

I suppose I'll have to in order to prove it's not the SD card.

Thanks again,
P

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Green Machine - slowly becoming multicoulored!

I guess another possibility is that there is an error in config.g that we can't see, that is messing up the execution. Try copying a fresh copy of config.g into both the /sys and /gcodes directories. If it still won't process config.g from /sys at startup, try 'printing' the other one.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

SUCCESS!!!!
As usual DC you're brilliant.

There was some sort of error in the config.g file; perhaps it was corrupted? I don' know. I didn't change anything except the name and the IP Addresses, so that's really odd.

I copied the config.g from the original firmware folder (like i did before) and it now works! M105 now brings up: ok T:8.4 B: 17.8 !!
The thermistor is still reading low (shouldn't they be pretty much the same?) but the point is it works!!!

Awesome, thanks so much for sticking with me!
You rock.

P

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Green Machine - slowly becoming multicoulored!

Regarding the hot end thermistor reading low, you can correct for that in my firmware fork (or zpl's) using the H parameter of the M305 command. If you do switch to my fork, you can keep your config.g and homing files, but you need to replace the web interface files if you want to use the web interface.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

Quote
parper101
SUCCESS!!!!
As usual DC you're brilliant.
There was some sort of error in the config.g file; perhaps it was corrupted? I don' know. I didn't change anything except the name and the IP Addresses, so that's really odd.
P

What application did you use to change the name & IP? It should be a simple text editor such as "Notepad" in Windows. More sophisticated word editors (such as "Word") may well put various tags and formatting characters in the file. By observation I believe that the Duet firmware can handle both Unix line endings (LF only) or DOS line endings (CR/LF), and either spaces or tab characters as delimiters, but other control characters may well have unpredictable effects.

Dave

Interestingly, the M503 output you supplied earlier in the thread looks okay, but is missing the M550 and M551 line that is in the config.g on github ( [github.com] ):

M550 PMy RepRapPro Ormerod 1 ; Machine name (can be anything you like)
M551 Preprap ; Machine password (currently not used)

So it looks like whatever you put in there may have messed up the config.g. I expect it started loading config.g, but then ignored the rest. Replacing your config.g with the standard one removed the problem.

For the low reported temperature on the hot end, see the third bullet point in the troubleshooting section here: [reprappro.com]

Ian
RepRapPro tech support