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Plug USB and battery same time blew LED's
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Please be positive and constructive with your questions and comments.

Plug USB and battery same time blew LED's

by jfalbo18 on Mon Mar 23, 2020 4:43 pm

in the manual it states that you can safely plug in both a battery power supply and USB at the same time and CPX will take the higher of the two. I did this with the battery even shut off and I blew all but three of my LEDs :-( have had the CPX for about two weeks.
just checking to see if this is something common or if there are any options to resolve? Thanks

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Re: Plug USB and battery same time blew LED's

by dastels on Tue Mar 24, 2020 11:26 am

That's weird. You have a battery box with a switch? If it was switched off then it's the same as a battery not being connected. And you are correct, the power circuitry automatically uses the higher voltage.

I'm curious: why do you say it blew all but 3 (which is, by itself, odd).

Dave

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Re: Plug USB and battery same time blew LED's

by jfalbo18 on Tue Mar 24, 2020 11:47 am

hi Dave when I tell the CPX to light up all lights on the ring only three light up. in addition when I eliminate the USB power and plug in the battery power the CPX doesn't respond. As if the battery is dead. Volt checked good.

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Re: Plug USB and battery same time blew LED's

by dastels on Tue Mar 24, 2020 11:58 am

What is your battery?

Dave

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Re: Plug USB and battery same time blew LED's

by jfalbo18 on Tue Mar 24, 2020 1:58 pm

https://www.amazon.com/gp/product/B00P2 ... UTF8&psc=1

Adafruit Accessories 3xAAA Battery Holder w/ On/Off Switch (1 piece)

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Re: Plug USB and battery same time blew LED's

by dastels on Tue Mar 24, 2020 2:23 pm

I can't think of any reason why this would have happened. Did you notice anything odd at the time? A bit of smoke, a burnt smell, flash?

What code was running at the time?

Dave

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Re: Plug USB and battery same time blew LED's

by jfalbo18 on Tue Mar 24, 2020 5:30 pm

the speaker chirped slightly no smoke or Sparks. running make code. Do you work for Adafruit?

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Re: Plug USB and battery same time blew LED's

by dastels on Tue Mar 24, 2020 7:01 pm

I'm freelancing for them, writing guides and helping on the forums as I can.

Does the board work other than the LEDs?

Dave

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Re: Plug USB and battery same time blew LED's

by jfalbo18 on Tue Mar 24, 2020 7:45 pm

I will run a series of tests on the rest of the board tomorrow. I'm even going to videotape what I can and send the link.
As long as this forum allows links you should be able to see everything I'm talking about.
I appreciate your time on this and appreciate the work Adafruit is doing with the face shields.
FYI I run a robotics program at a community college and like everyone else been forced to transition online.
Ran across MakeCode and some Adafruit projects and that is how I ended up using the Microbit and CPX.

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Re: Plug USB and battery same time blew LED's

by dastels on Tue Mar 24, 2020 8:36 pm

Yes, links are fine.

Very cool about the lab!

I'll watch for the video and testing results.

Dave

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Re: Plug USB and battery same time blew LED's

by dastels on Tue Mar 24, 2020 8:40 pm

Cool.

Gamesense was a feature the I developed at SteelSeries that let games publish events to our software (which controlled keyboard, mice, and such). One thing that could be done was control lighting on our devices. E.g. display game data using the lighting on your keyboard. See http://techblog.steelseries.com/2015/06/30/new-in-3.4.html

Dave

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Re: Plug USB and battery same time blew LED's

by jfalbo18 on Wed Mar 25, 2020 6:59 pm


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Re: Plug USB and battery same time blew LED's

by dastels on Wed Mar 25, 2020 8:28 pm

This is great! Thanks.

It seems really odd/suspicious that the first 3 pixels work, but not the subsequent ones. Can you have a look at the PCB area around the 4th pixel and between the 3rd and 4th. It feels like the chain has been broken somehow. If the power/ground connections to the 4th pixel or the data connection (a very visible trace near the Rx pad) from the 3rd to the 4th has been damaged it could explain what you are seeing. Also, look closely at the 4th pixel, comparing with the 1st through 3rd. If it's damaged somehow it would also explain what you see. A magnifying glass or jewelers loup would be handy for this inspection.

Dave

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Re: Plug USB and battery same time blew LED's

by jfalbo18 on Wed Mar 25, 2020 10:05 pm

Dave thanks for your time. A magnifying glass showed the problem. The edge of one of the LEDs is cracked.
Tell Adafruit to keep up the good work.....

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Re: Plug USB and battery same time blew LED's

by dastels on Thu Mar 26, 2020 8:49 am

OK, please email support@adafruit.com with a link to this thread, your order number, and request a replacement of 1 CircuitPlayground Express
I have no idea when it'll get shipped given the current situation, but this will get it into the system.

It seems the rest of the CPX is working fine. If you have a NeoPixel strip or ring you should be able to connect that. Depending on your equipment and skill (and availability of a spare neopixel - check digikey.com) you could replace the 4th pixel (note: these are the smaller neopixels). Or just work with the other features of the board for now.

Dave

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Please be positive and constructive with your questions and comments.