Single spdt switch working

NeonHorizon / lipopi

Guide to setting up LiPo batteries on the Raspberry Pi

GNU General Public License v3.0

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Single spdt switch working #25

Closed hex007 closed 7 years ago

hex007 commented 7 years ago

I was wondering if something like this will probably work. The goal is to switch the EN to float for some time and then close it (just like Push button NC). This will cause the powerboost to stay on till Pi is booted and automatically switch off once Pi boots down. I often forget to switch it off after shutdown. I tried making this and I faced two problems.

Without R1 the Pi causes speaker to emit high pitched noise.
The Uart Tx doesn't go low but stays high after powering down hence power boost stays on.

   Uart Tx  o-----'\/\/\,------o,
                     R1          'o----------------o  EN
         Floating ------->     o

NeonHorizon commented 7 years ago

What version Pi is this?

hex007 commented 7 years ago

Pi1

NeonHorizon commented 7 years ago

OK please disconnect your electronics, power up your Pi with a normal power adaptor and measure UART TX. Then shut it down and measure UART TX. What voltages do you get? You should get 3v3 when its on and 0v when its shut down (even with the power connected).

hex007 commented 7 years ago

I dont have a multimeter. Does it make a difference shutting down via sudo halt or sudo shutdown ?

EDIT : Seems that i should use shutdown command. You have specified in the article. Any reason for the speaker noise?

NeonHorizon commented 7 years ago

I wouldnt have thought it matters which you use. I don't know about the speaker noise I've not used LiPoPi with audio. Lets see what voltages you get as it may be that you have a wrong wire.

NeonHorizon commented 7 years ago

If you dont have a multimeter use an LED with the right size resistor.