Thermister terminal problem - HELP!!

[altarke]

The other day I had the thermistor create a short by having one of the hair like wire touch the hot head. As a result, at print time, I get the head temp to "run away" in the middle of printing and reach temps like 220C, in some sort of erratic fluctuation pattern. I tested the thermistor terminal on the RAMO board and it reads 61Kohms (I believe it needs to be 85Kohms). When I run the M303 s200 test I get "test failed temp too high".

In desperation, I connected the hot head and its thermistor to the 2nd head terminal output of the RAMBo, but it does not seem to register presence for the head, not can I control it. I suppose it may need some configuration changes somewhere to redirect/substitute the control from head 1 terminal and it fan and thermistor outputs to head 2 and it fan and thermistor.

I was wondering if anyone knows how to use the 2nd head terminal output (and its associated fan and thermistor ports) build into RAMBo board instead of the first one, and get it to work like before the short.

I am desperate - want to print and can`t -don't want to buy a new RAMBo card-Does anyone knows how to do it?

Thanks

[thenewguy]

If you shorted the thermistor input on the board your host will read like -20. If so you can change to one of the other 2 inputs. However to get host to read the correct imput you have to go to pins h in arduino. Someone posted how this was done before on the forums. I have done it but don't know off hand.

That's why I always check my thermistors with ohms before I plug them In. Learned my lesson.

[altarke]

If you shorted the thermistor input on the board your host will read like -20. If so you can change to one of the other 2 inputs. However to get host to read the correct imput you have to go to pins h in arduino. Someone posted how this was done before on the forums. I have done it but don't know off hand.

That's why I always check my thermistors with ohms before I plug them In. Learned my lesson.

...well I get good reading from the thermistor, it actually reads room temp when head not hot. the only problem is that in the middle of one print I saw erratic temp fluctuations while printing. Perhaps it's a bug in the program and I may not have an issue at all - but I still get an error while running m303 s200 (PID for the hot head temp monitoring system command ), I am thinking, it can not be good.

I would like to know how to do the pin assignment transfer from head 0 to head 1 in any event. I have this sinking feeling the short did not do the board any good....

In any event, where do you see this done on the forum here?

[mhackney]

altarke, I did this on my Rambo over a year ago and posted the cong and pins.h changes in my build log. You should be able to go to my log and search for it. Search for "pins.h".

regards,
Michael

[altarke]

altarke, I did this on my Rambo over a year ago and posted the cong and pins.h changes in my build log. You should be able to go to my log and search for it. Search for "pins.h".

regards,
Michael

You just can't imagine how happy you just made me

I would be delighted to look over the instructions - can U please provide an address -I find myself in some fishing store....

Many thanks

[altarke]

The "Oh Rats" part
When I was test fitting the aluminum sub-plate I had my Rostock connected to Repetier and plugged in. Nothing was on and the heaters were off. The aluminum contacted the electrical pad in the back and I got a little spark. So I immediately shut things down - I didn't realize I had it on actually.

Then when I hooked things up for a dry run I noticed the heated bed temp was 174°C! "That's not good" thought I and indeed it was not good. I measured the resistance of the thermistor and it was fine. I plugged the bed thermistor into the hot end jack and it was fine. I plugged the hot end thermistor into the heated bed jack and got an off the wall temp. So, it looks like I blew something on the RAMBo - probably the little capacitor. This is not a fused circuit.

The "Thank Heavens" part
The RAMBo has 4 heat control circuits. Two are for hotends and thermistors, one for the heated bed and there is an extra. So, a quick look at the RAMBo Development turned up the pin assignments. Pin 3 is the original pin assignment for the heated bed thermistor. Pin 7 is the thermistor input for the 4th thermistor connector on the RAMBo board. So, I edited Pins.h to:

#define HEATER_BED_PIN 3
//#define TEMP_BED_PIN 2
// I popped the thermistor input on my RAMBo so I'm using the 4th thermistor connector on the board.
#define TEMP_BED_PIN 7

Recompile, upload and all is well again.

I imagine this is what u r referring to - I still don't know even how to approach this reassignment - I want the associated inputs of the hot head fan and thermistor to be "moved" from head one to head two. This was I can just plug the power for the head heater into the terminal next to the old head and do the same to the fan and most importantly the thermistor. This way I will not be using the "blown" thermister terminal of the hot head 1.

Thanks

[altarke]

As I look over the Rambo dev page I think the whole project is alot esier then I initially thought. I don't need to relocate the entire head0 and fan with thermistor to the 2nd head terminal set - all I need to do is just relocate the malfunctioning thermistor pins T0 into T1.
I don't know however how to identify the ping on the board correctly - can U help?

Thanks

[Eaglezsoar]

As I look over the Rambo dev page I think the whole project is alot esier then I initially thought. I don't need to relocate the entire head0 and fan with thermistor to the 2nd head terminal set - all I need to do is just relocate the malfunctioning thermistor pins T0 into T1.
I don't know however how to identify the ping on the board correctly - can U help?

Thanks

Let's try this

Edit Pins.h
Find Rambo or Motherboard 301

You should see

#define HEATER_BED_PIN 3
#define TEMP_BED_PIN 2

#define HEATER_0_PIN 9
#define TEMP_0_PIN 0

#define HEATER_1_PIN 7
#define TEMP_1_PIN 1

#define HEATER_2_PIN -1
#define TEMP_2_PIN -1

Change to:

#define HEATER_BED_PIN 3
#define TEMP_BED_PIN 2

#define HEATER_0_PIN 9
#define TEMP_0_PIN 1 // Was Pin 0

#define HEATER_1_PIN 7
#define TEMP_1_PIN 0 // Not Functioning PIN 0

#define HEATER_2_PIN -1
#define TEMP_2_PIN -1


Save Pins.h
Using Arduino open Repetier.ino and upload to Rambo

[altarke]

Save Pins.h
Using Arduino open Repetier.ino and upload to Rambo

Will try this out as soon as I get home

THANKS THANKS THANKS THANKS THANKS THANKS THANKS THANKS THANKS

[Eaglezsoar]

Save Pins.h
Using Arduino open Repetier.ino and upload to Rambo

Will try this out as soon as I get home

THANKS THANKS THANKS THANKS THANKS THANKS THANKS THANKS THANKS

Save your thanks until we get it working. I am new to this remapping stuff myself but I did my best to find out since the lack
of responses. Change where the thermistor plugs into the Rambo to the next one down. All the remapping does is change which pin the physical
connection uses. Please let me know the results and make sure that you choose the right motherboard in Pins.h
It will say Rambo or Motherboard 301. After remapping and uploading, turn off the printer then back on.

[altarke]

As soon as I am able to print with confidence that the hot head will not thermally run away I will be happy to share with all the numerous improvements and mods I implemented/ Things like new carriages using only 3 wheels, magnets all around, carbon fiber rods, lockable adjustments screws and more....

I wish to thank u for your efforts and mostly for caring to look up and respond to my problem

Thanks

[dpmacri]

Save Pins.h
Using Arduino open Repetier.ino and upload to Rambo

Will try this out as soon as I get home

THANKS THANKS THANKS THANKS THANKS THANKS THANKS THANKS THANKS

Save your thanks until we get it working. I am new to this remapping stuff myself but I did my best to find out since the lack
of responses. Do not change where the thermistor plugs into the Rambo. All the remapping does is change which pin the physical
connection uses. Please let me know the results and make sure that you choose the right motherboard in Pins.h
It will say Rambo or Motherboard 301. After remapping and uploading, turn off the printer then back on.

Umm, I think you're going to need to move the pin that the thermistor is plugged into. With the remapping shown, the thermistor that was plugged into Thermistor input 0 will now need to be plugged into thermistor Pin 1.

[Eaglezsoar]

Save Pins.h


Umm, I think you're going to need to move the pin that the thermistor is plugged into. With the remapping shown, the thermistor that was plugged into Thermistor input 0 will now need to be plugged into thermistor Pin 1.

Dpmacri, you may very well be correct. This is my first attempt at remapping the thermistor ports. All I wanted to do was to change the physical Thermistor port 0 to use a different pin # of 1 instead of 0. We would appreciate greatly your help
if you can. How would I change the first physical Thermistor Port 0 to use pin 1 instead of 0? He has burned out his first port and now that I think about it if is it burned out changing the pin number is not going to fix it. So what you are saying is
that If I keep the changes we were going to use we just would need to change the thermistor down to input 1? Will my proposed mappings accomplish this?

[dpmacri]

Save Pins.h


Umm, I think you're going to need to move the pin that the thermistor is plugged into. With the remapping shown, the thermistor that was plugged into Thermistor input 0 will now need to be plugged into thermistor Pin 1.

Dpmacri, you may very well be correct. This is my first attempt at remapping the thermistor ports. All I wanted to do was to change the physical Thermistor port 0 to use a different pin # of 1 instead of 0. We would appreciate greatly your help
if you can. How would I change the first physical Thermistor Port 0 to use pin 1 instead of 0? He has burned out his first port and now that I think about it if is it burned out changing the pin number is not going to fix it. So what you are saying is
that If I keep the changes we were going to use we just would need to change the thermistor down to input 1? Will my proposed mappings accomplish this?

I think you've got it right, Eaglezsoar with your mappings, based on my reading of the RAMBo schematics. I haven't actually done this, though, but the mappings currently in pins.h agree with what I see on the schematics.

So with your change, just moving the thermistor physical connection from 0 to 1 should do the trick.

[Eaglezsoar]

Thank You!

[Eaglezsoar]

Save Pins.h
Using Arduino open Repetier.ino and upload to Rambo

Will try this out as soon as I get home

THANKS THANKS THANKS THANKS THANKS THANKS THANKS THANKS THANKS

I never heard anything back so I assume that this did not work?

[Eric]

Yes, the physical port has to be abandoned in cases like this. Each one is connected to a particular pin on the Arduino chip, and what's actually been blown is that input on the processor itself, usually by subjecting it to excessive voltage (over 6V). So, unless you're a hack who can cut traces and physically remap things to unused inputs (with associated changes to pins.h), too many mistakes eventually means replacing the board entirely.

(Or in the case of a stacked-board setup like Ramps 1.4, it's the the CPU board that needs replacing, not the ramps board.)

[Eaglezsoar]

Yes, the physical port has to be abandoned in cases like this. Each one is connected to a particular pin on the Arduino chip, and what's actually been blown is that input on the processor itself, usually by subjecting it to excessive voltage (over 6V). So, unless you're a hack who can cut traces and physically remap things to unused inputs (with associated changes to pins.h), too many mistakes eventually means replacing the board entirely.

(Or in the case of a stacked-board setup like Ramps 1.4, it's the the CPU board that needs replacing, not the ramps board.)

I understand what you are saying and the Ramps has only one ADC and all the thermistor ports are multiplexed to it but the usual case if one of the Thermistor ports is blown
the others still work and just need a Pins.h remap. In this case, it may have taken out the ADC. I haven't heard anything back so I don't know but I hate it when someone has
to lay more hard earned money for a new board.

[Eric]

the Ramps has only one ADC and all the thermistor ports are multiplexed to it

You're confused. In terms of hardware, Ramps and Rambo (and most of the others) do nearly everything the same way using the same software, they're just different ways of packaging the same/similar hardware. The ADC you refer to is one of the analog input pins on the CPU...there are 16 such inputs on a 2560.

From the fix-it point of view, I love the Ramps version of the electronics. Blow a stepper driver, you just replace that one driver board ($10-15). Blow all your thermistor inputs, you just replace the CPU board($20, and you might still be able to use the old one for other projects). Those are probably the top two problems right there.

Digipots are the one great feature of the Rambo. They're manual pots on ramps. That just about covers the functional differences.

[Eaglezsoar]

the Ramps has only one ADC and all the thermistor ports are multiplexed to it

You're confused. In terms of hardware, Ramps and Rambo (and most of the others) do nearly everything the same way using the same software, they're just different ways of packaging the same/similar hardware. The ADC you refer to is one of the analog input pins on the CPU...there are 16 such inputs on a 2560.

From the fix-it point of view, I love the Ramps version of the electronics. Blow a stepper driver, you just replace that one driver board ($10-15). Blow all your thermistor inputs, you just replace the CPU board($20, and you might still be able to use the old one for other projects). Those are probably the top two problems right there.

Digipots are the one great feature of the Rambo. They're manual pots on ramps. That just about covers the functional differences.

I am confused, I always thought that part of the Arduino board was a separate ADC IC, I did not realize it was part of the processor. Thanks for enlightening me.
So much to learn, so little time. It makes me wonder why so many switched from Ramps to the Rambo. Probably because it had a smaller footprint.

[altarke]

Save Pins.h
Using Arduino open Repetier.ino and upload to Rambo

Will try this out as soon as I get home

THANKS THANKS THANKS THANKS THANKS THANKS THANKS THANKS THANKS

I never heard anything back so I assume that this did not work?

....so first of all, I want to thank to all for their input.

Now, as soon as I got home I did the remapping of the pins ( the instructions Eaglezsoar provided were right on- thanks again) and of course I moved the connector to the 2nd set of pins and to my delight it registered. BUT, I still was unable to run the M303 S200 test, getting the same error as before.
This leads me to believe that just remapping the pin does not resolve the issue. If the particular central and only thermal component of the RAMBo board is defective then all thermal functions will be effected, unless (maybe there are independent thermal monitoring system for each of the hotheads (BIG IF)) then, maybe if I will get the whole 2nd hothead set to work (now it will not work if 1st hothead is not present)instead of the 1st.

In any event, I printed something last night and all went well, so I may not be in a rush to get me a new board -but once we talking about a new board - does anyone know when the next revision of RAMBo boards is out? there was some talk about having it run on 32 bit ( and not 16 bit as it is now) I don't want anyone to think that I know what would be the benefit of having it work in 32 (I once read something on the board here that it would be very beneficial ).

[Eaglezsoar]

Altarke says:
In any event, I printed something last night and all went well, so I may not be in a rush to get me a new board -but once we talking about a new board - does anyone know when the next revision of RAMBo boards is out? there was some talk about having it run on 32 bit ( and not 16 bit as it is now) I don't want anyone to think that I know what would be the benefit of having it work in 32 (I once read something on the board here that it would be very beneficial ).


You may have a long wait. I personally feel that if finances can afford it you should have a backup Rambo card. Send the old one to Ultimachine for repair.
The 32 bit will be awhile, especially when you consider that a lot of the software will need to be redone to be compatible. If you are willing to be down for a week or so at a time
while ordering a new board in, then fine. If not I would consider if your finances can handle the purchase of the new Rambo as above. I realize as well as anyone the price tag of
a new Rambo and in my opinion they are overpriced compared to Ramps etc. but they certainly are nice to have around when the need arises.

[altarke]

You may have a long wait. I personally feel that if finances can afford it you should have a backup Rambo card. Send the old one to Ultimachine for repair.
The 32 bit will be awhile, especially when you consider that a lot of the software will need to be redone to be compatible. If you are willing to be down for a week or so at a time
while ordering a new board in, then fine. If not I would consider if your finances can handle the purchase of the new Rambo as above. I realize as well as anyone the price tag of
a new Rambo and in my opinion they are overpriced compared to Ramps etc. but they certainly are nice to have around when the need arises.

I may just get another Rambo board and use the old one for 2nd printer I am in the process of designing/building . It will have magnetic arms lockable adjusting screws. (These are all the issues I found problematic in the default Seemecnc stock MAX Printer).
I already implemented them with in the MAX I build and found improved printing quality.
(I would be happy to send anyone STL's if they desire)

[Eaglezsoar]

You may have a long wait. I personally feel that if finances can afford it you should have a backup Rambo card. Send the old one to Ultimachine for repair.
The 32 bit will be awhile, especially when you consider that a lot of the software will need to be redone to be compatible. If you are willing to be down for a week or so at a time
while ordering a new board in, then fine. If not I would consider if your finances can handle the purchase of the new Rambo as above. I realize as well as anyone the price tag of
a new Rambo and in my opinion they are overpriced compared to Ramps etc. but they certainly are nice to have around when the need arises.

I may just get another Rambo board and use the old one for 2nd printer I am in the process of designing/building . It will have magnetic arms lockable adjusting screws. (These are all the issues I found problematic in the default Seemecnc stock MAX Printer).
I already implemented them with in the MAX I build and found improved printing quality.
(I would be happy to send anyone STL's if they desire)

I would like to see the STL files.