Turn off power draw for the Particle Electron IC2 battery only shield

Hardware
1

Hello NCD community!

I have an Electron connected to the PR35-17 IC2 battery only shield.
It works perfectly as i want, but i would like to turn off the boost circuit, so that it isn’t drawing unnecessary power, when unused (in sleep mode).

I believe I read (before it was taken away) that you could cut the boost circuit power, by setting the A3 pin to low on the electron. I can even see the connection to the boost circuit on the board.
But when I set the A3 pin to LOW, nothing happens. It still flows 5V out the I2C power pin.
I’ve checked with my multimeter, that the power on A3 is in fact cut, and it is.

What am I doing wrong?

This is discussed earlier here:
https://forum.ncd.io/content/Turn-power-draw-Particle-Electron-IC2-battery-only-shield
but as said, it apperently isn’t sold anymore:
https://store.ncd.io/product/i2c-shield-for-particle-electron-or-particle-photon-for-battery-only-power/

Thanks in advance,
Nme

2

Hi,
The A3 does shut down the boost circuit but when the boost circuit is off it bypasses the input voltage to the i2c port. We were not aware of this when we designed the product( this is the reason we took it away).
We can issue a refund If you want.
Thanks

3

Ah i see, that makes sense.

I was then looking at this product:

And was wondering if it is possible to cut the power to that via some pin?
If not, are you creating a board that has this feature eventually?

Btw now that we are on the topic, do you have an idea of what kind of MOSFET could be used instead?

(About the refund, I kind of bought the board because it had the power cut, so it would be nice with a refund :wink: )

Thanks

Nme

4

Yes, you can use a n-channel fet to cut the 5V line.

We are building for new particle modules, we can share an early prototype with you if you want.

Thanks

5

@Bhaskar Is it possible to get the PCB drawing of the PR35-17, you know the components and all (perhaps even in EAGLE format?)

I want to make it part of a bigger board with other things I need for my Particle device. And if I get it to work as intended, I can send the schematics.

What are the features of this prototype?
If we skip the refund on the PR35-27, could I receive one of those early prototypes without the hassle of getting money involved?

Nme

7

in the new version

  1. there is a boost circuit ( 5V/400mA)
  2. Cut off circuit ( this will disable all the on board power as well i2c port power)
  3. will work with new particle and feather boards

Sure, i will ship you an early prototype ( will be out in 3 weeks)

I will see if i can get a sch for you.

Thanks

1 Like
8

Do you have my information for shipment, @Bhaskar?
And could you get the I2C shield schematic for me?