proximity sensor

Hello RepRap Community,

I'm almost done with the construction of my RepRap printer.

At the moment i got stuck at captiel "Commissioning" in the manuel. more precisely at the commissioning of the proximity sensor. The Problem is when i send the command G31, i get a Value between 200 and 400 back. When i put a piece of paper under the sensor, the Value doesn`t change. They Value is always located between 200 and 400. I have checked several times the connection of the Sensor on the Duet Board. I also checked the Firmware Version of my RepRap. The SD Card works also fine. I have two questions

⦁ Have someone an idea what would could be wrong with my sensor , the configuration or the Duet board ?

⦁ I wanted to try an nother AD Port. So i compiled the RepRap Software on my computer. Do I only have to change the Value of the Variable "Z_PROBE_PIN" in the Header File "Platform.h", to change the entrance of the AD converter ? So when i change the Value to Z_PROBE_PIN (10), the Software uses the AD10 entrance on Pin 37.

Thank you in advance for your help and sry for my weak english

best greetings from Austria
Stom

Hi Stom,

If the z-probe reading doesn't change when you put a piece of paper under the sensor, then it sounds as if there is no connection between the IR sensor output and the ADC input of the SAM3X. I think the most likely explanations are that you have connected the blue wire to the wrong pin on the expansion connector, or that there is a bad crimp connection at one end of the blue wire in the sensor loom. However, it's also possible that the Duet PCB or the sensor PCB has an open-circuit.

One way of testing the Duet PCB is to disconnect the sensor loom from the Duet PCB and connect the pin on the expansion connector (the one that the blue wire is normally connected to) to ground. You should then get a z-probe reading very close to zero. Caution: if you accidentally connect the pin to +5V or +12V, you will destroy the SAM3X processor.

You should only need to change the value of Z_PROBE_PIN to switch to a different ADC input.

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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].

Hi Stom

There is a troubleshooting guide for the proximity probe here, which may help: [reprappro.com]
Use the first picture in this thread as a guide if you want to check the voltages - it's possible the board has been poorly soldered and something is not making good contact: [forums.reprap.org]
We'll happily replace the board if there is a fault with it. Sorry, I'm not the best at advising on how to recompile the firmware - I seem to mess it up every time I make a change!

Ian
RepRapPro tech support

Hi,

thank you for the quick response and sry for my late answer, bacause of my work i am not often at home at the moment!

I have read your suggestions. So i wanted do measure the Voltage on the four pins of my Sensor. During this, i have noticed that the contact of my blue and the black wire are connected trough the joint. That should not be?

Thanks Stom

Quote
stom
Hi,

thank you for the quick response and sry for my late answer, bacause of my work i am not often at home at the moment!

I have read your suggestions. So i wanted do measure the Voltage on the four pins of my Sensor. During this, i have noticed that the contact of my blue and the black wire are connected trough the joint. That should not be?

Thanks Stom

No they should not be joined. That is poor quality soldering.

Regards,

Les

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Pointy's Things
Pointy's Blog

Hi Stom

No, they shouldn't be connected. I don't think it will have damaged the board, but does explain why you get a limited range of readings. Can you fix it yourself (should be easy if you have soldering iron) or do you want a replacement? If replacement, please email me on support at reprappro dot com to make it official. As we don't have access to our distributor's customer databases, I'll need to know your full name and address, your RS order number (or other proof of purchase) and whether you have a kit with red or green printed plastic parts.

Ian
RepRapPro tech support

No thx i will try to fix it by my self ! but i have to wait until next week

thanks for your help, i hope this is the failure.

regards
Stom

While that soldering is clearly a problem, I don't think it's the whole problem. If you have a short between the pins connected to the blue and black wires, then I agree that it would not damage the board. However you should get a constant zprobe reading close to zero.

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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].

Hi and thanks for your help

finaly i could continue to work on my RepRap

so i separated the two soldered joints. Lo and behold it works. After that, i “homed” my axies, this worked also.

But after that, my “heated bed” Senor didnt worked any more. I also could not start the heated bed and heater on the hot end. All three things have already worked. So I removed the firmware, that i have compiled and installed the last Firmware Version for the Duet board. This also didnt help. So i removed the cable to the “heated bed” and the jumper witch supplies the heater and the motors with 12 V. I restarted and reset the Printer. Then i re-connected the cable for the “heated bed” and jumper correctly. And restarted the printer. Now the “heating bed” is working again. But the heater on the hot still doesnt work :/ if i am hoenstly i am not sure why the “headed bed” is working again and what exactly the issue was. This drives me crazy

I hope u can help me again,

best regards

Edited 2 time(s). Last edit at 05/24/2014 06:55AM by stom.

It sounds like loose connections to the heaters and/or thermistors. The IDC header should be OK but the other plug pins are difficult to crimp adequately, and perhaps the easiest solution is to solder those connections. I was fortunate in building the unit at work where we have the correct crimping tools (some crimping tools cost over £100 !)

Dave
(#106)