Re: Improvement to IR sensor mounting February 03, 2014 01:01PM |
Registered: 10 years ago Posts: 132 |
Re: Improvement to IR sensor mounting February 03, 2014 01:03PM |
Registered: 10 years ago Posts: 14,672 |
Re: Improvement to IR sensor mounting February 03, 2014 02:58PM |
Registered: 10 years ago Posts: 132 |
Re: Improvement to IR sensor mounting February 03, 2014 05:59PM |
Registered: 10 years ago Posts: 14,672 |
Re: Improvement to IR sensor mounting February 05, 2014 11:38AM |
Registered: 10 years ago Posts: 14,672 |
Re: Improvement to IR sensor mounting February 05, 2014 12:28PM |
Registered: 10 years ago Posts: 132 |
Re: Improvement to IR sensor mounting February 05, 2014 12:39PM |
Registered: 10 years ago Posts: 14,672 |
Re: Improvement to IR sensor mounting February 05, 2014 02:24PM |
Registered: 10 years ago Posts: 132 |
Re: Improvement to IR sensor mounting February 05, 2014 04:43PM |
Registered: 10 years ago Posts: 14,672 |
Re: Improvement to IR sensor mounting February 05, 2014 07:17PM |
Registered: 10 years ago Posts: 2,472 |
Quote
dc42
John,
1. Yes that is still the circuit I am using for the modulated sensor. However, if I were building it again, I would reduce the 1K resistor between collector and emitter to about 470 ohms, because I think this will further reduce the sensitivity to ambient light.
Re: Improvement to IR sensor mounting February 05, 2014 07:34PM |
Registered: 10 years ago Posts: 14,672 |
Quote
dmould
Surely that resistor keeps the LED partially on all the time, reducing the difference between the "on" illumination and the "off" illumination, and reducing it will increase the "off" illumination reducing the difference? I would have thought no resistor at all would give the best effect - i.e. when switched off by the Duet, the LED is completely dark so you are only measuring ambient light.
Re: Improvement to IR sensor mounting February 06, 2014 07:43AM |
Registered: 10 years ago Posts: 2,472 |
Re: Improvement to IR sensor mounting February 06, 2014 08:20AM |
Registered: 10 years ago Posts: 14,672 |
Quote
dmould
I also intend to fit a white LED strip under the heatsink cover to provide illumination for the print, as suggested elsewhere. I suspect that this fixed illuminator might achieve the same thing and obviate the need for the resistor.
Re: Improvement to IR sensor mounting February 06, 2014 08:41AM |
Registered: 10 years ago Posts: 2,472 |
Quote
dc42
Quote
dmould
I also intend to fit a white LED strip under the heatsink cover to provide illumination for the print, as suggested elsewhere. I suspect that this fixed illuminator might achieve the same thing and obviate the need for the resistor.
I doubt it - visible LED lighting does not produce a significant amount of IR.
Re: Improvement to IR sensor mounting February 06, 2014 09:10AM |
Registered: 10 years ago Posts: 14,672 |
Re: Improvement to IR sensor mounting February 06, 2014 10:37AM |
Registered: 10 years ago Posts: 14,672 |
Re: Improvement to IR sensor mounting February 07, 2014 07:02AM |
Registered: 10 years ago Posts: 132 |
Re: Improvement to IR sensor mounting February 07, 2014 07:19AM |
Registered: 10 years ago Posts: 14,672 |
Re: Improvement to IR sensor mounting February 07, 2014 07:34AM |
Registered: 10 years ago Posts: 147 |
Quote
dc42
Thanks John, that one looks good!
I'm considering designing a new, larger pcb for the modulated IR sensor. The pcb would also feature a reliable and more easily dismantled connector for connecting all the hot end parts, and one or more LEDs to illuminate the print.
Re: Improvement to IR sensor mounting February 07, 2014 01:44PM |
Registered: 10 years ago Posts: 14,672 |
Quote
PaulHam
Quote
dc42
Thanks John, that one looks good!
I'm considering designing a new, larger pcb for the modulated IR sensor. The pcb would also feature a reliable and more easily dismantled connector for connecting all the hot end parts, and one or more LEDs to illuminate the print.
I'm Interested in that if you come to selling them
Re: Improvement to IR sensor mounting February 07, 2014 09:58PM |
Registered: 10 years ago Posts: 119 |
Quote
dc42
Quote
PaulHam
Quote
dc42
Thanks John, that one looks good!
I'm considering designing a new, larger pcb for the modulated IR sensor. The pcb would also feature a reliable and more easily dismantled connector for connecting all the hot end parts, and one or more LEDs to illuminate the print.
I'm Interested in that if you come to selling them
John, do you think the pcb should stick to my original modulated IR sensor design (so you need to run another wire back to the Duet), or should I put an attiny processor on it to do the modulation and emulate the unmodulated sensor?
Re: Improvement to IR sensor mounting February 08, 2014 06:08AM |
Registered: 10 years ago Posts: 132 |
Presumably you are trying to reduce noise by adding the attiny processor, is the noise still a problem with your latest design.So not sure what you are going to gain in performance, maybe some additional functionality. I'll continue to make my PCB from your current design. I'm going to make up a new loom with the additional wire, 4 way header one end and 2 x 2 way headers on the other end, keeping it compatable with the current sensor. At least if you go ahead with the addional processor I will have something to measure it against.Quote
dc42
John, do you think the pcb should stick to my original modulated IR sensor design (so you need to run another wire back to the Duet), or should I put an attiny processor on it to do the modulation and emulate the unmodulated sensor?
Re: Improvement to IR sensor mounting February 08, 2014 06:18AM |
Registered: 10 years ago Posts: 14,672 |
Re: Improvement to IR sensor mounting February 08, 2014 10:42AM |
Registered: 10 years ago Posts: 14,672 |