Powering Trinket 5V from external 5 volt supply?

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twrackers
 
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Powering Trinket 5V from external 5 volt supply?

Post by twrackers »

I see on the documentation pages of both the Trinket and Pro Trinket, both 5V versions, that they are usually powered by either (a) regulated 5 volts into microUSB jack, or (b) 5.5 volts and up to at least 12 volts into the BAT+ or equivalent pin. Is there a way to power either of these devices from a regulated 5 volts that is NOT coming in via a USB cable, say one such device getting its power from the Vout pin of another? This would allow a single USB cable to power both and eliminate the need for a small USB hub just to split out power two ways.

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Re: Powering Trinket 5V from external 5 volt supply?

Post by adafruit_support_bill »

If you have a regulated 5v source, you can feed power via the GND and USB pins. The USB pin is directly connected to the VBUS pin of the USB jack.

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dastels
 
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Re: Powering Trinket 5V from external 5 volt supply?

Post by dastels »

You would want to use a diode the same way one is used on the Vbus line from the USB connector. See https://learn.adafruit.com/assets/10774. This avoids problems if both the 5v pine AND USB are connected at the same time.

That said, the old (non-M0) Trinkets and ProTrinkets aren't a good idea for new projects. As stated on the project page:
Deprecation Warning: The Trinket bit-bang USB technique it uses doesn't work as well as it did in 2014, many modern computers won't work well. So while we still carry the Trinket so that people can maintain some older projects, we no longer recommend it. Please check out the Trinket M0. It has built-in USB, more capabilities, and is comparable in price!
Dave

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twrackers
 
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Re: Powering Trinket 5V from external 5 volt supply?

Post by twrackers »

dastels wrote: Mon Apr 10, 2023 8:05 pm That said, the old (non-M0) Trinkets and ProTrinkets aren't a good idea for new projects.
I know, but it's a one-time project and I prefer to use a part I already have if it can work (the Trinket 5V) before I go obsoleting parts and buying new. I am transitioning new projects from the Pro Trinket 5V to the Itsy Bitsy 32u4, in fact an Itsy Bitsy is the main control processor for this project, and all the Trinket needs to do when enabled by the Itsy Bitsy is to flash an LED and repeatedly trigger an Audio FX board to mimic the warning strobe and alert sound of a railroad turntable in motion (a specific one in Japan which I made a YouTube of). The Trinket handles that just fine, only 3 GPIO pins required.

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Re: Powering Trinket 5V from external 5 volt supply?

Post by dastels »

Cool. I just wanted to be sure you knew. It's a nice little board, but its handling of USB can be problematic.

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twrackers
 
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Re: Powering Trinket 5V from external 5 volt supply?

Post by twrackers »

Yep, hold reset and click upload on IDE, wait for a few lines to scroll down on build then release reset. I'm used to it. Nice that the Itsy Bitsy doesn't require that ^_^ ... and I can program it with the Raspberry Pi IDE, which can't handle Trinkets, Pro or otherwise >_< o_O .

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