Powerboost 1000C switch/sensor

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Fireshark
 
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Powerboost 1000C switch/sensor

Post by Fireshark »

Hi, I'm relatively new to this, and hit a snag of confusion.

For the Adafruit Powerboost 1000C, I'd like to switch the 5V power on and off using a hall sensor (US5881LUA).
I believe I can use this in some manner with the VS, EN and G pins, and a resistor.

What orientation do these pins need to be?
Would it be possible to make it such that when a magnet is nearby, the power is on?

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adafruit_support_mike
 
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Re: Powerboost 1000C switch/sensor

Post by adafruit_support_mike »

Yep.. power the Hall effect sensor between Vs and GND, and connect the PowerBoost's En pin to the Hall sensor's output pin.

When the sensor detects a magnet, it will turn on its internal mosfet, pulling En to GND and disabling the PowerBoost's 5V output.

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Fireshark
 
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Re: Powerboost 1000C switch/sensor

Post by Fireshark »

adafruit_support_mike wrote:Yep.. power the Hall effect sensor between Vs and GND, and connect the PowerBoost's En pin to the Hall sensor's output pin.

When the sensor detects a magnet, it will turn on its internal mosfet, pulling En to GND and disabling the PowerBoost's 5V output.
Hi Mike!
So the leftmost pin is VS, middle is GND, and the right 'listen' pin is to EN?

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adafruit_support_mike
 
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Re: Powerboost 1000C switch/sensor

Post by adafruit_support_mike »

It depends on the orientation of the part.

The datasheet has a drawing and pinout table on page 3:

https://cdn-shop.adafruit.com/datasheet ... rev007.pdf

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Fireshark
 
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Re: Powerboost 1000C switch/sensor

Post by Fireshark »

adafruit_support_mike wrote:It depends on the orientation of the part.

The datasheet has a drawing and pinout table on page 3:

https://cdn-shop.adafruit.com/datasheet ... rev007.pdf
Okay, I see it. It looks to be what I described, then with the UA part!
The hall sensor will only turn OFF the connection, right? It can't be used to do the opposite (when a magnet is near to turn things on).

Thank you for your advice.

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adafruit_support_mike
 
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Re: Powerboost 1000C switch/sensor

Post by adafruit_support_mike »

That sensor will only pull EN low when a magnet is close.

There are other sensors which have the kind of output you want though. This one has complementary output, so one pin stays low until a magnet is nearby:

https://www.mouser.com/ProductDetail/Di ... GW1Q%3d%3d

karxpava
 
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Re: Powerboost 1000C switch/sensor

Post by karxpava »

In using a AH277AZ4-CG1 normally closed Hall effect sensor with the powerboost, would one also connect a 10k resistor between one of the output pins and VDD?

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adafruit_support_mike
 
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Re: Powerboost 1000C switch/sensor

Post by adafruit_support_mike »

Yes. The outputs on that one are open-drain, and require a pull-up resistor.

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The_Feral_Child
 
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Re: Powerboost 1000C switch/sensor

Post by The_Feral_Child »

Hi,
I would like to use the US1881 latching hall sensor to switch the PowerBoost 1000c on/off. I have drawn the attached diagram based on the previous posts in this thread and the information the manufacturer provided for a three-wire circuit for harsh environments because the device I am powering will be going underwater. Would this work?
Thanks,
Farrell
Attachments
US1881 Hall Sensor Switch for PowerBoost 1000C.png
US1881 Hall Sensor Switch for PowerBoost 1000C.png (10.59 KiB) Viewed 172 times

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adafruit_support_mike
 
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Re: Powerboost 1000C switch/sensor

Post by adafruit_support_mike »

D1, Z1, and R1 prevent voltage spikes large enough to damage the sensor, and probably won’t be necessary if you power the sensor from the LiPo. Other than that, the circuit looks okay.

For the sake of clarity, Rpu and C2 need to connect to the sensor’s output.

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The_Feral_Child
 
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Re: Powerboost 1000C switch/sensor

Post by The_Feral_Child »

Mike,
Thank you for your reply, it is good to know that I do not need the extra components (D1,R1, and Z1).
Farrell

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