geekhack
geekhack Projects => Making Stuff Together! => Topic started by: BlindAssassin111 on Sun, 29 July 2018, 20:11:31
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Okay, I have decided to give handwiring a go so I don't have to design a PCB and either run a GB to buy the extras or spend too much just for this.
One thing I really want though is underglow, I have a strip of WS2812Bs, 60 per meter, and I was wondering how many LEDs would be a good amount to use for a fullish size board? The whole case is ~430mm wide and I was debating about getting it printed in PETG to allow it to glow a bit.
I know the LEDs max out at 50mA each, I don't know what the max the Teensy 2.0 and USB ports are willing to give, so that is where I need help.
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Here's a chart (https://www.pjrc.com/teensy/low_power.html) listing power Teensy 2.0 requirements.
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Here's a chart (https://www.pjrc.com/teensy/low_power.html) listing power Teensy 2.0 requirements.
? That is just a chart of the power draw that the Teensy needs to run, not how much it can supply.
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The Teensy dosen't supply power. The power is supplied by the USB. So, available USB power minus required Teensy power (from the chart) equals remaining available power.
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Here's a chart (https://www.pjrc.com/teensy/techspecs.html) which lists digital I/O power. maybe this will be more useful.
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The Teensy dosen't supply power. The power is supplied by the USB. So, available USB power minus required Teensy power (from the chart) equals remaining available power.
Okay, makes more sense that you brought that up now. Still not sure how much current my USB ports can supply though...Would it most likely be 1.5A per port? My mobo has USB3.1 ports(both gen1 and gen2 Type-A) but I can't find any mention of current ratings for the ports besides the fact they meet the spec, which I can't seem to find anymore than the "up to 100W" info, and I highly doubt the ports can support 20A...
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The Teensy dosen't supply power. The power is supplied by the USB. So, available USB power minus required Teensy power (from the chart) equals remaining available power.
Okay, makes more sense that you brought that up now. Still not sure how much current my USB ports can supply though...Would it most likely be 1.5A per port? My mobo has USB3.1 ports(both gen1 and gen2 Type-A) but I can't find any mention of current ratings for the ports besides the fact they meet the spec, which I can't seem to find anymore than the "up to 100W" info, and I highly doubt the ports can support 20A...
Yeah, there is a charging spec for USB 3, but to enable it you have to negotiate (for higher power, it also switches to 9V,12V or 20V, depending on what's requested). But unless you want to light a room, you certainly do not need that much power. You should be able to limit the power to the WS2812 by only allowing lower values to RGB, like only the lower 4bits per channel. The input values probably do not scale linearly with current consumed, so you will need to do some tests. I do not think that you need any more than 500mA to make more light than you would want...
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Yeah, there is a charging spec for USB 3, but to enable it you have to negotiate (for higher power, it also switches to 9V,12V or 20V, depending on what's requested). But unless you want to light a room, you certainly do not need that much power. You should be able to limit the power to the WS2812 by only allowing lower values to RGB, like only the lower 4bits per channel. The input values probably do not scale linearly with current consumed, so you will need to do some tests. I do not think that you need any more than 500mA to make more light than you would want...
I was expecting to limit brightness but I guess testing would be the best idea then. I was just wanting to get help so I could integrate the LEDs into the case before hand rather than trying to setup a test system.
Still don't know a good number of LEDs, my strip has 60 total, and if I limited it to half brightness the max it should pull(if linear)would be 1.5A, but it would probably be best to not use all of them(might use half of them), I was just planning on lining the front and sides for underglow, but due to the density of LEDs, I was worried about power consumption.
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The Kona Classic has optional underglow via LED strips and I think 15 LEDs looks nice on a TKL sized board (about 13in wide). The strips I used are 30 LEDs/meter.
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The Kona Classic has optional underglow via LED strips and I think 15 LEDs looks nice on a TKL sized board (about 13in wide). The strips I used are 30 LEDs/meter.
Yeah I wish I had bought a less dense strip now...but it was really cheap and I just bought it on a whim. I am going to have to figure a lot of things out in order for this to look like I want, without having too many LEDs.
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The Kona Classic has optional underglow via LED strips and I think 15 LEDs looks nice on a TKL sized board (about 13in wide). The strips I used are 30 LEDs/meter.
Yeah I wish I had bought a less dense strip now...but it was really cheap and I just bought it on a whim. I am going to have to figure a lot of things out in order for this to look like I want, without having too many LEDs.
You can just cut between the LEDs and space 'em out however you want. It's more work, but certainly doable.
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You can just cut between the LEDs and space 'em out however you want. It's more work, but certainly doable.
Good point...Wasn't thinking of spacing out each LED, that would be quite a bit of work, but it would allow me to have more uniform lighting with less LEDs and less current.