Anyone interested in a modulated IR sensor + fan control + illumination board?

I'll go for option 5. Will support for the ultrasonic be included in future revisions of the firmware, or will the ultrasonic transducer present itself to the firmware as an IR sensor?
How to proceed from here? Do you want to have people send you money by paypal?
All the best,

Onno

And I'll have an option 5 also please.

Mike

Ill go full monty if possible:
option 5 + (soldered through-hole parts + 4th sensor wire)
is that too much to ask for (will pay extra)

What is the difference between the 3-wire modulated IR sensor & the 4-wire modulated IR sensor (except 1 wire)

I'll go for kit 5 please

Could I order a kit 2 and a kit 4 please?

Cheers

Ray

Kit four 5 for me please
(unless ultrasonic prooves to be more reliable in your tests or you decide to "drop" kit 4 due to low demand)
thanks in advance!

edit: better to have all options, let's go for 5

Edited 1 time(s). Last edit at 02/18/2014 10:51AM by auser.

I would like a kit 1.. bare pcb.. I think I already have most of the reqd bits! Thanks!

regards
Andy

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Ormerod #318
www.zoomworks.org - Free and Open Source Stuff

@onno, I'm looking at both options, i.e. emulating an IR sensor as well as additional support in the firmware. The second option gives more flexibility and would allow temperature compensation to be applied, but the first option may be good enough if the bed is always heated to the same temperature before homing.

@PaulHam, the 4-wire sensor is based on the IR sensor I am using at present, with the modulation and demodulation done by the Duet. The 3-wire one uses the onboard microcontroller to do the modulation and demodulation, and its output emulates an unmodulated sensor.

I will provide an ultrasonic-only option (i.e. no IR support) if/when I get it working well enough. This would need to be used in conjunction with a microswitch for x-homing.

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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 dc42,
Thank you for all your work.
Can I order a kit 5 please
Thanks again
Paul

Hi DC 42,

I would like a Kit 1 and a Kit 4 please.

Yes, thanks for all the great work on this.

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Ormerod #007 (shaken but not stirred!)

Hi
Can you put me down for kit 4 please.
Thanks

Hi @DC42 - Sounds great...full Monty for me please with kit 5 - how do you want to handle payment?

@dc42 - I originally asked for a full populated board, Option/Kit 5 will be great please, gimme a shout if you need a guinea pig =)

Matt

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Limited Edition Red RS Ormerod 1 #144 of 200 - RRP 1.09fw
iamburnys Ormerod Upgrades Github
Follow me on ThingiVerse My Designs

Hi dc42,

Great work with the circuit's mate. Are you keen on sharing the schematic for this board mate? I am curious to see if you have any filtering on the output? (bandpass centered on your modulation frequency, etc).

I am an electronics designer, engineer and I have just purchased an ormerod (should be delivered this afternoon) from RS.

I design circuit boards daily using the latest Altium Designer and would love to assist where I could to help out the community.

Keep up the great work!

:-)

Dan

Hi

You can put me down for a kit 3

Thanks

Martin

Hi DanV, I will release the schematic when I ship the first units. I don't want to buy parts for 50 kits and then have lots of orders cancelled because someone else rushes the design out. I don't have bandpass filtering on the output of the IR sensor (because I don't believe it is needed), I just have a minimal high-pass filter. Currently my Ormerod uses a modulated sensor with the modulation done by the Duet at about 83Hz, and this is performing well. It shows a very slight sensitivity to very strong incandescent lighting, due to 50Hz modulation in the light I believe. The board I have designed will modulate the IR at 1kHz or higher, which allows the mcu to average out the signal over at least 12 times more cycles and should reduce the sensitivity to 50Hz. Ideally we would sample over a complete number of 50Hz or 60Hz mains cycles, however this would slow down the response time too much.

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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 dc42 my preference is kit 5 thanks

Hi dc42

Thank you for all your work and god answers.

Can I order a kit 5 please

Jan

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XB70

Last week I said
"Yes please to a full board DC"
Please make that a Kit 5
Greg

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Ormerod #17

Hi

Put me down for a populated board too, if you can cope...

Thanks
Jim

I have not looked at this thread for a while, so I would like a kit 5 please.

Alan

Hi,

I'll also take a kit 5, please.

And thank you for all the great work!

/Allan

Looks like I may be up to 50 orders soon, in which case I can probably afford to get them assembled professionally!

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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
Looks like I may be up to 50 orders soon, in which case I can probably afford to get them assembled professionally!

How many more orders do you need to make that viable?

I am sure I am not the only one who would be happy to take an additional kit to get the numbers up, always nice to have a spare!

Mike

I agree with you Mykey, I would take an extra one as well if that's what it takes (assuming delivery isn't delayed too much).
I really appreciate the effort put into this improvement for the Ormerod.Thanks dc42!

Can l order a kit 5 please
Chris

Quote
dc42
Hi DanV, I will release the schematic when I ship the first units. I don't want to buy parts for 50 kits and then have lots of orders cancelled because someone else rushes the design out. I don't have bandpass filtering on the output of the IR sensor (because I don't believe it is needed), I just have a minimal high-pass filter. Currently my Ormerod uses a modulated sensor with the modulation done by the Duet at about 83Hz, and this is performing well. It shows a very slight sensitivity to very strong incandescent lighting, due to 50Hz modulation in the light I believe. The board I have designed will modulate the IR at 1kHz or higher, which allows the mcu to average out the signal over at least 12 times more cycles and should reduce the sensitivity to 50Hz. Ideally we would sample over a complete number of 50Hz or 60Hz mains cycles, however this would slow down the response time too much.

Hi DC42,

I understand what you mean when it comes to not releasing your schematics, etc.
Without seeing your schematic I can't really make any constructive comments, etc. But I do honestly think adding an active 2nd order bandpass filter to the output of the sensor would be beneficial (the parts required are relatively small when smd components are selected).
I know you have done a whole heap of testing though and you are happy that you don't need anything else apart from your minimal high pass filter, thats fair enough too :-) I am not trying to step on anyone's toes or anything mate, I am just trying to help out where I can.

Is there any way I can help you out mate? (I am in Australia so maybe I can assist with people here who are interested?)

If not, I understand about not wanting to share anything. Do you care if I spin up my own PCB for this then? I don't want to cause any problems and I would prefer to work collectively rather than separately, but I do understand where you are coming from mate.

Hows your testing with the ultrasonics going?

Once again, I am not trying to cause any problems, just trying to help out if I can, where possible.

Cheers,

Dan

Hi Danv,

I really don't think an external bandpass filter is needed, given the coherent detection that I am doing in software. Even with the current 83Hz modulation, the variation in the reading from the modulated IR sensor seen by the Duet is dominated by noise from the switching regulator on the Duet. I guess it is possible that I will see some interference if I point a 38kHz IR remote control transmitter at the white tape under the sensor, and I will try this when I revert to an IR sensor again (I'm currently testing with ultrasonic). I can't think of any sources of ambient IR that are not VLF (sunlight and heating appliances), 50/60Hz (incandescent lighting), or around 38kHz (remote controls).

Modern practice in mixed analog/digital systems is to do most of the signal processing in software. External filtering is typically used in such systems only to avoid aliasing and/or when there is a large unwanted component that would saturate the ADC if not filtered out. In this case, the only device that saturates is the sensor head.

Testing with ultrasonics has revealed that the series resonant frequency of the transducer is quite temperature-sensitive - looks to be around 3% for a temperature change of 50C. This will complicate the design, because the transducer is most sensitive to the phase of the reflected wave at or within 1% of its series resonant frequency.

Edited 1 time(s). Last edit at 02/18/2014 06:22PM 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 was just thinking more along the lines of a plug-n-play approach that requires no firmware changes.
Run an on-board oscillator for modulation with filtering and retain the 3-wire connector without the need for a 4th wire to be added from the Duet? Just to keep it simple that's all.
I haven't looked at your firmware changes either, I probably should, so you are well in your opinion of no filtering is required.

Yeah I can't think of any other sources of ambient IR either mate.

Have you also considered capacitive sensors?