Mini differential IR height sensor board

Hi Jerry, I think you need to configure it as a fixed probe, but I can't help you beyond that because I haven't used Marlin for two years. Try asking in The Firmware - Mainstream section.

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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].

Hey you wordpress site shows a v 1.2 of this board? Is that released and/or available? Whats the difference between that and v 1.1 board?

Version 1.2 uses SMD optical components and works with a wider range of reflectivity of the bed surface. They have been shipping for a few weeks.

Edited 1 time(s). Last edit at 10/15/2016 02:00PM 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].

Quote
dc42
Version 1.2 uses SMD optical components and works with a wider range of reflectivity of the bed surface. They have been shipping for a few weeks.

Does this version of the board produce more constant results across different parts of the bed? (i.e. margin of error reduced across different points).

Hello David,

I bought several of your different sensors for my ormerod and one of your mini sensors a while back probably 18 months or so. I have only just got round to incorporating the mini sensor into my new coreXY, I have a Duet 0.6 left over which I have used for this. As per the instructions on your website I connect the power to the sensor from the extruder endstop connector and the out pin to the AD12 pin (6th pin across from the ethernet connector end on the row nearest the processor.

So I think it is setup correctly, Multimeter shows 4.25v on the power lines, I thought this should be 3.3v from the board layout displayed in Kicad showing extruder connector.
However, the red LED lights up continuously, there is no flashing at any time.
Web interface shows a value of 715 which never changes.

Is the board toast in your opinion or is there some other debug I can try to see what miss-configuration I might have made?

Lloyd

If the LED is on permanently but dim, this usually means there is no 3.3V or 5V power to the sensor. Please measure the power between the top end of the inductor L1 on the sensor and the ground test pad which is above the D2 legend. If you are getting 4.25V between them, send me a PM with your invoice number and I will replace the sensor.

However, if the 3.3V rail on your Duet is at 4.25V then you need to fix that because the SAM processor won't like being run at 4.25V.

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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

Interestingly, the 12V LED power supply from ebay was setup to provide 15v from the manufacturer. I have never actually looked at this I just assumed a 12v PSU did as it advertised.
With 15v the Duet regulators produced the 4.25v on the 3.3v line.
So I turned the preset pot down and unfortunately, this only reduced the voltage to 13.5v and still left the 3.3v line at 4.25v,

I suspect but have no proof, the regulator for the 5v and then 3.3v lines saturate at somewhere about 12.5v and then clamps the output of the 3.3v line at 4.25v

If this is the case then other people who have turned this pot on their power supplies up to 14.5v to get better heating times etc, may be running their SAM processors and 3.3v logic at 4.25v instead.

As you say probably not a good idea long term.

I then removed J9, which forces the Duet to use the USB to power the duet and low and behold the 3.3v supply is now 3.3v

Needless to say, I will be investing in a better quality PSU which can provide 12v when requested.

Lloyd

Hi Lloyd,

The Duet is quite happy with up to 30V power, so 15V is no problem for it. But it sounds to me that the 3.3V regulator on your Duet is probably faulty and should be replaced. With USB power there is an additional diode in the circuit, which would account for the 3.3V rail being nearer the correct voltage.

David

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Hi

ok, for the moment I have plugged a mains to 5v usb charger in to run the Duet from the USB socket and that seems to provide the correct voltages etc.

Lloyd

Hey

I know this is a 3 year-old post but would but I want to use this to connect to an arduino so just print out the distance and i will adjust till the desired distance is reached. will this set-up work?

Also I have a mirror as my build plate will it work on the mirror?

thank you

Edited 1 time(s). Last edit at 05/09/2017 12:57AM by bshady3.

You can buy the sensor from me here [escher3d.com] or in the USA from Filastruder.

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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].

will this work on a mirror bed?

Mirror is one of the few surfaces we advise against. See section "Bed surface" at [miscsolutions.wordpress.com].

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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 David,

Just did the measurement you requested in your post of januari 6 2016. My megtronics board (ramps 1.4 based) with fresh marlin 1.1.x takes 6 full seconds to enable pullups on the endstops. So my sensor needs unplugging and replugging after every startup to make the led blink twice instead of four times.
Is it possible for me to flash the sensor firmware with a custom startup time? If not I will use the physical pullup resistor that you suggested.

Cheers,

Diederik van der Pant

Edited 1 time(s). Last edit at 06/13/2017 02:09AM by djvdpant@gmail.com.

Yes it would be possible to increase the delay from its current value of 5 seconds. You can find the firmware source at [github.com]. But unless you have a suitable programmer, it's easier to add the pullup resistor.

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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,

So yesterday my Mini IR Board arrived which i installed promptly. I did some UBL test measurements as well as repeatability tests and i was impressed with the consistent readings the sensor delivered throughout the mesh of my plate. I had also adjusted my Z height properly via storing an offset so as to have the desired distance of the nozzle from my glass bed. However now comes the not so happy part. I wanted to do a quick grid level check print and there i saw the the measured heights for the nozzle are way off at some points. What i mean by that is that the print starts normally and lays down good lines but at certain sections of the bed the nozzle is clearly too high (at some points this seems to be roughly 2mm-ish above the bed!). Of course this results in spagetti layers which don't stick to the glass at all.

I have a Wanhao I3 printer with a 4mm glass plate. The bed under the glass plate is almost completely black. There are a few spots which have white logos and writings on them as well as some corners where i still have some green silicone pads. I use Ramps board running Marlin btw.

I'm kinda bummed about these results as the probe was quite fast (compared to my BL Touch which requires constant deploying per point) and the accuracy of the repeated measurements seems to be excellent however i guess the accuracy of the actual measured distance between the glass and the desired set Z height is sometimes way off which results in the above described behavior.

Is there any special setting i may still need to tweak in my marlin config or anything else that i could do to improve the measured distance to my glass plate?

Cheers

Hi,

My guess is that the differences in trigger height correspond to the points where the surface under the bed is not black (although 2mm sounds like a very large difference). Can you confirm this? If so, here are some possible solutions:

- Put a piece of black paper between the glass and the bed plate
- Paint the white parts black
- Adjust the probing grid parameters to avoid parts that are not black
- Use black glass instead of clear glass

One other possibility is that you have bright sunlight reflecting off the bed into the phototransistor, causing it to saturate. If that happens, the LED will blink rapidly to warn you. It can be a problem if you have a south facing window (in the northern hemisphere) and it is a bright sunny day, especially in the winter when the sun is low.

HTH David

Edited 2 time(s). Last edit at 11/25/2017 06:10AM 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].

Quote
dc42
Hi,

My guess is that the differences in trigger height correspond to the points where the surface under the bed is not black (although 2mm sounds like a very large difference). Can you confirm this? If so, here are some possible solutions:

One other possibility is that you have bright sunlight reflecting off the bed into the phototransistor, causing it to saturate. If that happens, the LED will blink rapidly to warn you. It can be a problem if you have a south facing window (in the northern hemisphere) and it is a bright sunny day, especially in the winter when the sun is low.

HTH David

Hi David,

Actually where i noticed these incorrect heights are over areas that are black. Sunlight is also not a factor as that does not reach the print bed in such a direct way nor was it a sunny moment when i did this. The leds did not blink as far as i remember in the sort of pattern that you mentioned.

Atm i have my printer disassembled for other reasons but i will give it another few trys next week.

Cheers

Hi David,

I've started having problems with my IR sensor V1.1 not being reliable, and now it's packed up completely. I don't get any read at all. However if I get a CD and place the shiny side towards the sensor I get a reading of 1000 in the duet web site around the trigger hight. This is the only time I get a reading. If I use cardboard, photo paper or any other surface I don't get any reading at all. Any Ideas?

PS. I've just order the V1.2 of your website so hopefully a new one will sort the problem out, but thought I'd post incase you can offer advise in the mean time, so I can carry on printing while I wait for the order.

Dan, it sounds to me that one of the two IR LEDs has failed, or possibly one of the LED series resistors has failed. If you view the sensor with a digital camera or mobile phone camera from the right angle (i.e. directly into the diode lenses), you may be able to tell which diode isn't working.

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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].

Thanks for the reply... Recieved your new one today, and it seems to be way better than my old one. So thank you for the quick turn around.... All set up and seem to have a more consider z probe than I've ever had before.

Thanks, it's nice having satisfied customers

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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].

Greetings All!

I have had the MD IR Sensor installed for a number of weeks. One very bothersome problem is that the sensing distance seems to creep(normally driving the nozzle into the bed) after successive prints. I have made sure the mounting and hottend is tight, so I'm pretty sure there are no mechanical issues with the physical offset to the nozzle; the build surface is PrintinZ black. Usually creeps at the rate of roughly .1mm at a time...I adjust the Z offset to compensate and I seem to be chasing a moving target. Ultimately it will land back at the original value and start the process over again. Using a Duet WiFi controller board.

Any suggestions? Thanks in advance!

Edited 1 time(s). Last edit at 04/04/2018 11:21AM by rmd59.

Check whether there is any varying tilt in the hot end that could change the relative heights of the nozzle and the bed. If your hot end uses printed support parts then the heat from the nozzle and heater block could be causing them to deform slowly.

If you have the older sensor with through hole optical components then it's possible for their alignment to change, but that normally happens only if they collide with something.

HTH David

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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].

Many thanks for the quick reply, David!

No supports on the carriage or supporting structures; and the phenomena happens even if I run a print at night and then start a new one in the AM...I don't think heating of the components is an issue...

New sensor BTW...got it from Filastruder about 6 weeks ago...

Can you post a photo showing how you have mounted the sensor?

Edited 1 time(s). Last edit at 04/05/2018 10:46AM 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].

Here it is...

Unfortunately that pic is rather dark and I can't see the IR sensor.

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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].

Sorry about that...I brightened it up a bit and circled where the Sensor is. It is completely shrouded except on the bottom which is unobstructed.

Can you post a picture from underneath? I am wondering whether there could be any reflected light from your metal surround that is causing the high trigger height.

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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].