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TPL5110 to cycle only once when button is pressed
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TPL5110 to cycle only once when button is pressed

by vin7102 on Sun Aug 04, 2019 12:51 am

Hey Guys,

The TPL5110 sounds like a perfect fit for my 3v project but I need a little clarification.
I only need this unit to power some LED's for 2 hours after the tactile button is pressed, then shut down indefinitely until the button is pressed again (which may be a day or a week later).
Can I make this happen with this board?

Thanks,
Vin

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Re: TPL5110 to cycle only once when button is pressed

by adafruit_support_mike on Sun Aug 04, 2019 1:50 pm

The TPL5110 has a one-shot mode, but the breakout is wired for continuous restarts. The trace you’d need to cut and reconnect is under the chip, so there’s no easy way to modify the board for to use one-shot mode.

We do have the Push-Button Power Switch which can do roughly the same thing:

https://www.adafruit.com/product/1400

Pressing the button turns power on, and there’s a logic input that can turn power off again. You’ll need something to generate the turn-off pulse, but if you’re already using a microcontroller it’s easy to run a counter and allocate a GPIO pin.

If you don’t already have a microcontroller, a Gemma M0 or Trinket M0 can do the job:

https://www.adafruit.com/product/3501
https://www.adafruit.com/product/3500

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Re: TPL5110 to cycle only once when button is pressed

by HermieDug on Sun Aug 25, 2019 10:03 am

I also require the TPL5110 breakout to run in one shot mode. I wondered if de soldering pin 6, and connecting it to ground would then set the chip to One_shot, can anyone advise before I try it.

Thank,

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Re: TPL5110 to cycle only once when button is pressed

by adafruit_support_mike on Sun Aug 25, 2019 12:19 pm

Nope.. the connection you’d need to break is under the chip.

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Re: TPL5110 to cycle only once when button is pressed

by HermieDug on Sun Aug 25, 2019 2:30 pm

adafruit_support_mike wrote:Nope.. the connection you’d need to break is under the chip.

Is there an image of the track any where, but I'm confused, why is de soldering the pin of the chip and isolating it from the track, different to cutting the track that goes under the chip. Can you help me find more info.

Someone else suggested shorting the Drv and Done pin to simulate the trigger being applied.

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Re: TPL5110 to cycle only once when button is pressed

by HermieDug on Sun Aug 25, 2019 5:01 pm

Ok so farther searching I found this fabrication design imag. If I cut the track under the EN/One_shot contact I would be cutting the Vdd feed to the rest of the circuit, but if I lift the contact, insulate it and connect it to Gnd, the system would then be in One_shot mode.


https://learn.adafruit.com/assets/39784

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Re: TPL5110 to cycle only once when button is pressed

by adafruit_support_mike on Wed Aug 28, 2019 12:13 am

That will work in theory. In practice, move gently when you're ready to bend the pin up and away from the pad. SOT-323 pins are thin, and snap off at the edge of the package easily.

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Re: TPL5110 to cycle only once when button is pressed

by HermieDug on Wed Aug 28, 2019 4:21 am

adafruit_support_mike wrote:That will work in theory. In practice, move gently when you're ready to bend the pin up and away from the pad. SOT-323 pins are thin, and snap off at the edge of the package easily.


I'm still waiting for it to arrive, thanks for the warning :) if I ruin the chip I could buy a new one to solder to the board. Ideally it would be good if it was designed with solder pads to select what mode you want, or even a jumper selector.

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