Mini differential IR height sensor board I am about to make another small batch of my mini differential IR height sensor board. This uses 2 beams of infrared light to detect height above the bed surface. It is designed to work on glass with or without a covering of Kapton tape, ABS juice etc, but works on most surfaces including BuildTak. Not suitable for use on mirror glass. [img]https://dl.dropboxusercontent.com/u/19369680/2015-05-07%2021.49.55.jpg[/img] I can ship to most countries. Prices in GBP including shipping (tracked where possible), for one board paid via PayPal, are: [code] UK inc. VAT 29.82 EU VAT paid 37.83 Rest of world 32.52 [/code] VAT-registered business customers in the EU but outside the UK may claim the "Rest of world" price, but you must give me your VAT registration number, and if you are in Italy you must be VIES-registered as well. To order, send me a PM stating how many boards you want, your PayPal email address, and which country you are in. If you are in the EU and claiming the "Rest of world" price, also your VAT registration number. I will send a payment request via PayPal when the boards are imminent. I expect to start shipping this batch on 22 June. Also send me a PM if you would like a price for more than one board. For further details and fitting instructions see https://miscsolutions.wordpress.com/mini-height-sensor-board/. There is a video showing the board being used to auto-calibrate a delta printer at https://www.youtube.com/watch?v=xVrRGaeOiKA. https://reprap.org/forum/read.php?94,519697,519697#msg-519697 Sun, 09 Aug 2026 22:21:47 -0400 Phorum 5.2.23 https://reprap.org/forum/read.php?94,519697,892703#msg-892703 Re: Mini differential IR height sensor board https://reprap.org/forum/read.php?94,519697,892703#msg-892703
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dc42
Yes, if you add an external resistor.

Thanks for help, yes it is working good now with resistor.]]> CptanPanic For Sale Tue, 09 May 2023 07:39:38 -0400 https://reprap.org/forum/read.php?94,519697,892700#msg-892700 Re: Mini differential IR height sensor board https://reprap.org/forum/read.php?94,519697,892700#msg-892700 dc42 For Sale Tue, 09 May 2023 03:28:24 -0400 https://reprap.org/forum/read.php?94,519697,892699#msg-892699 Re: Mini differential IR height sensor board https://reprap.org/forum/read.php?94,519697,892699#msg-892699
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dc42
You can tell whether the sensor has started up in analog or digital mode by counting the number of LED flashes after power up. See the instructions at [miscsolutions.wordpress.com].

Yes 4 flashes, so it is in analog mode, so I guess something is wrong with internal pull-up. I think it may because the way klipper works, it takes a bit for the pin to get configured, so pull-up is not active at start. So can I do manual override pull-up?]]> CptanPanic For Sale Mon, 08 May 2023 19:04:25 -0400 https://reprap.org/forum/read.php?94,519697,892694#msg-892694 Re: Mini differential IR height sensor board https://reprap.org/forum/read.php?94,519697,892694#msg-892694 miscsolutions.wordpress.com].]]> dc42 For Sale Mon, 08 May 2023 16:03:33 -0400 https://reprap.org/forum/read.php?94,519697,892693#msg-892693 Re: Mini differential IR height sensor board https://reprap.org/forum/read.php?94,519697,892693#msg-892693
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dc42
If the sensor doesn't detect a pullup resistor to +3.3V or +5V then it operates in pseudo-analog mode, outputting 4 different voltages depending on whether it is a long way from the bed, close to the bed but not quite triggered, close enough to be triggered, or overloaded with ambient light. If the board it is connected to treats the input as digital then it might see the "close to the bed but not quite triggered" as triggered. So maybe you just need to enable the pullup resistor on the input of the board that it is connected to.

Thanks that is a good clue. But unfortunately I do have pull-up enabled on that pin. But I have verified that I can put it in a position, where it is far enough that the LED does not light, but still shows up as triggered. I guess I need to verify externally that the pin is being configured correctly for pull-up resistor?]]> CptanPanic For Sale Mon, 08 May 2023 15:14:57 -0400 https://reprap.org/forum/read.php?94,519697,892692#msg-892692 Re: Mini differential IR height sensor board https://reprap.org/forum/read.php?94,519697,892692#msg-892692 dc42 For Sale Mon, 08 May 2023 11:59:02 -0400 https://reprap.org/forum/read.php?94,519697,892687#msg-892687 Re: Mini differential IR height sensor board https://reprap.org/forum/read.php?94,519697,892687#msg-892687 I sent this also to contact-us form on your site, but doesn't seem to be working correctly.

But I have a IR board that I have purchased in 2017, and has worked great, but recently I started using this printer again after a year layoff, and I getting in major outliers .75-1mm in the same position. Also strange is I have the firmware(klipper) checking 3 samples per position now, and sometimes I see that it gets a sample and the LED on sensor doesn't turn on, is it possible that a detection is sent without turning on the LED? Any thoughts? Anything that might degrade after 6 years?

Thanks.]]> CptanPanic For Sale Mon, 08 May 2023 08:33:42 -0400 https://reprap.org/forum/read.php?94,519697,845117#msg-845117 Re: Mini differential IR height sensor board https://reprap.org/forum/read.php?94,519697,845117#msg-845117 [reprap.org]]]> skippy2235 For Sale Tue, 22 Jan 2019 08:42:49 -0500 https://reprap.org/forum/read.php?94,519697,845082#msg-845082 Re: Mini differential IR height sensor board https://reprap.org/forum/read.php?94,519697,845082#msg-845082 dc42 For Sale Tue, 22 Jan 2019 02:58:53 -0500 https://reprap.org/forum/read.php?94,519697,845070#msg-845070 Re: Mini differential IR height sensor board https://reprap.org/forum/read.php?94,519697,845070#msg-845070 sinned For Sale Mon, 21 Jan 2019 20:16:31 -0500 https://reprap.org/forum/read.php?94,519697,844956#msg-844956 Re: Mini differential IR height sensor board https://reprap.org/forum/read.php?94,519697,844956#msg-844956 I just recived my Mini height sensor board ver 1.2
I installed in on my zonestar (RepRap Prusa i3 CLONE) witrh Marlin firmware.

So I powered up the sensor and right away, LED come on and flashes 2 times, just like you said it would.
All wires are correct.
After homing the printer and find that it will not goto Z home. Instead it goes up about 10mm and stops.
I enter the M119 command and find that:
With the sensor a long way above any surface, the LED on the sensor is off, and printer firmware does indicate that the sensor is triggered.
AND
With the sensor closer to a surface LED does illuminate and printer firmware does indicate that the sensor is NOT triggered.

How do I fix this.
Rewriting firmware to my printer is not an easy task, as I do NOT have the source code and would have to do a complete install of Marlin.
Is there a way to change the firmware on the height sensor, and what would I change.
Dave]]> skippy2235 For Sale Sun, 20 Jan 2019 01:18:40 -0500 https://reprap.org/forum/read.php?94,519697,825580#msg-825580 Re: Mini differential IR height sensor board https://reprap.org/forum/read.php?94,519697,825580#msg-825580 JKaechler For Sale Wed, 13 Jun 2018 23:08:46 -0400 https://reprap.org/forum/read.php?94,519697,825574#msg-825574 Re: Mini differential IR height sensor board https://reprap.org/forum/read.php?94,519697,825574#msg-825574
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JKaechler
I had some trouble with the IR sensor back when i was running plain glass over an aluminum heatbed. Now I am running borosilicate glass 1/4" thick, and i have a proper ramps/marlin board running now..... so i have a question. Would it help or hurt to sand the top surface of that boro glass to make it sort of opaque. would the ir reflect better off it? sanding with something really fine like 220 grit, and an orbital electric sander.

I have no experience with sanding glass but when I did the same to PEI I got height variance assuming due to the fact that the reflections are different across the surface depending on the sanding pattern and level.]]> Idefix For Sale Wed, 13 Jun 2018 18:38:48 -0400 https://reprap.org/forum/read.php?94,519697,825567#msg-825567 Re: Mini differential IR height sensor board https://reprap.org/forum/read.php?94,519697,825567#msg-825567 JKaechler For Sale Wed, 13 Jun 2018 15:51:56 -0400 https://reprap.org/forum/read.php?94,519697,824023#msg-824023 Re: Mini differential IR height sensor board https://reprap.org/forum/read.php?94,519697,824023#msg-824023
If the sensor isn't giving the same trigger height at different places, then obviously that will cause issues too - although if the measured trigger height variation is 0.25mm but the height map variation is 0.8mm then it evidently isn't the whole story.

One other issue that can cause height map errors is if the tilt of the print head varies with XY position. This is a common problem on delta printers, but rare on most other sorts of printer. If the tilt of the print head varies with position, so will the relative height of the IR sensor and the nozzle.

HTH David]]> dc42 For Sale Thu, 31 May 2018 04:58:31 -0400 https://reprap.org/forum/read.php?94,519697,823970#msg-823970 Re: Mini differential IR height sensor board https://reprap.org/forum/read.php?94,519697,823970#msg-823970
I am using a RAMPS board with Marlin 1.1.8_bugfix and have tried both Bilinear and Unified Bed Leveling. My surface is 1/4" glass and I have tried it with and without hairspray. I painted my aluminum build plate with flat black grill paint- though I am tempted to give it another coat to be sure that its opaque enough. The glass sits on silicone heat transfer pads.

Consistently, the bed level mapping results in the same shape for the bed surface- a saddle or Pringles potato chip, 0.8mm high at one corner, 0.4mm high across from it, and 0.2mm on the diagonal across from it. Thing is, when I take my machinist rule and lay it across the glass- there are no gaps or voids under laying it across the same directions.

I just can not seem to get it to be consistent and zero out for the bed.

Any thoughts or ideas or things to check?]]> sinned For Sale Wed, 30 May 2018 16:40:20 -0400 https://reprap.org/forum/read.php?94,519697,820992#msg-820992 Re: Mini differential IR height sensor board https://reprap.org/forum/read.php?94,519697,820992#msg-820992 The sensor is securely mounted and does not wobble. I will run a few more tests to ensure the issue is not at another place in the setup and report back.]]> Idefix For Sale Wed, 02 May 2018 08:56:20 -0400 https://reprap.org/forum/read.php?94,519697,820911#msg-820911 Re: Mini differential IR height sensor board https://reprap.org/forum/read.php?94,519697,820911#msg-820911
Variance using BuildTak or other opaque surfaces should be lower.

Obviously if the sensor isn't securely mounted, it may wobble and give inconsistent results.If the tilt of the print head or the bed varies, that will cause the relative heights of the sensor and the nozzle to change, causing an apparent different in trigger height.

HTH David]]> dc42 For Sale Tue, 01 May 2018 13:26:47 -0400 https://reprap.org/forum/read.php?94,519697,820830#msg-820830 Re: Mini differential IR height sensor board https://reprap.org/forum/read.php?94,519697,820830#msg-820830
I'm trying to get the IR sensor to work now for a couple of months.
In particular, I'm seeing a high variance (>0.1mm) which makes the bed leveling and G29 operation a nightmare :-(
Initially, I thought the PEI bed I used was the issue (although painted black on the back etc) so I upgraded the bed to a Buildtak Flex system but after installation, I still see a similar behavior, unfortunately.

Buildplate: Buildtak flex (Buildtak on spring steel) - Buildtak flex is mounted on top of the heated glass bed.
Controler: DuetWifi FW 1.21
Trigger height: varies between 2.65 and 2.9mm - note: when G30 probing is used multiple times in a raw the accuracy is there but after a restart of the system it varies (e.g. nozzle is suddenly touching the bed or gap is too large to get the first layer down.

Will take some screenshots of the bed compensation and mesh leveling process and post them here later.

I assume I'm doing something fundamentally wrong or my assumptions that the variance should be much lower are incorrect.
Any advice is highly appreciated.

Thanks !]]> Idefix For Sale Mon, 30 Apr 2018 22:15:43 -0400 https://reprap.org/forum/read.php?94,519697,818101#msg-818101 Re: Mini differential IR height sensor board https://reprap.org/forum/read.php?94,519697,818101#msg-818101
I'll adjust the base edges of the surround to be around 1.5mm higher than the bottom edge of the board. Right now they are line-to-line.]]> rmd59 For Sale Tue, 10 Apr 2018 16:46:39 -0400 https://reprap.org/forum/read.php?94,519697,818094#msg-818094 Re: Mini differential IR height sensor board https://reprap.org/forum/read.php?94,519697,818094#msg-818094 dc42 For Sale Tue, 10 Apr 2018 15:59:12 -0400 https://reprap.org/forum/read.php?94,519697,817864#msg-817864 Re: Mini differential IR height sensor board https://reprap.org/forum/read.php?94,519697,817864#msg-817864
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dc42
I can't be completely sure because the focus of the shot from underneath isn't great, but I think that the edge of the fan duct with the cutout in it for the capacitor isn't sufficiently clear of the IR LEDs and phototransistor.

David, is there a minimum recommended distance that the bottom edge of the sensor should clear any surrounding shrouds?]]> rmd59 For Sale Mon, 09 Apr 2018 08:54:22 -0400 https://reprap.org/forum/read.php?94,519697,817709#msg-817709 Re: Mini differential IR height sensor board https://reprap.org/forum/read.php?94,519697,817709#msg-817709
I'm using the ir probe for a year now, and my delta printer had gorgeous results : perfect first layers all the time.

Yesterday, I changed my hot-end, so I rebuild the effector, and changed some firmware parameters...

But now I'm having a very very strange result : The probe triggers way too high, about 5-6cm above the bed ! It makes the G32 calibration sequence impossible as it is very inaccurate too.

What would be causing this? As anyone ever experienced such thing ?

here is a video of the problem

[youtu.be]]]> Archiclem For Sale Sun, 08 Apr 2018 06:59:31 -0400 https://reprap.org/forum/read.php?94,519697,817646#msg-817646 Re: Mini differential IR height sensor board https://reprap.org/forum/read.php?94,519697,817646#msg-817646 rmd59 For Sale Sat, 07 Apr 2018 12:31:18 -0400 https://reprap.org/forum/read.php?94,519697,817638#msg-817638 Re: Mini differential IR height sensor board https://reprap.org/forum/read.php?94,519697,817638#msg-817638 dc42 For Sale Sat, 07 Apr 2018 10:27:31 -0400 https://reprap.org/forum/read.php?94,519697,817483#msg-817483 Re: Mini differential IR height sensor board https://reprap.org/forum/read.php?94,519697,817483#msg-817483 rmd59 For Sale Thu, 05 Apr 2018 20:31:56 -0400 https://reprap.org/forum/read.php?94,519697,817444#msg-817444 Re: Mini differential IR height sensor board https://reprap.org/forum/read.php?94,519697,817444#msg-817444 dc42 For Sale Thu, 05 Apr 2018 11:51:59 -0400 https://reprap.org/forum/read.php?94,519697,817440#msg-817440 Re: Mini differential IR height sensor board https://reprap.org/forum/read.php?94,519697,817440#msg-817440 rmd59 For Sale Thu, 05 Apr 2018 11:16:00 -0400 https://reprap.org/forum/read.php?94,519697,817437#msg-817437 Re: Mini differential IR height sensor board https://reprap.org/forum/read.php?94,519697,817437#msg-817437 dc42 For Sale Thu, 05 Apr 2018 10:48:36 -0400 https://reprap.org/forum/read.php?94,519697,817393#msg-817393 Re: Mini differential IR height sensor board https://reprap.org/forum/read.php?94,519697,817393#msg-817393 rmd59 For Sale Thu, 05 Apr 2018 06:09:10 -0400