Phat beat on/off button


#1

I’m exploring the pirate radio kit. I’ve been looking at how the on/off button works using the internet radio script specifically and I noticed that the on/off button reliably switches off but not on.

From reading the pinout, I’m not sure how it could act as an on switch; could someone confirm that it cannot or have I missed something?


#2

I might very well be wrong here but I was under the impression that the button was designed for turning off and on the radio (ie in software rather than turning on and off the hardware).

Generally though, it’s more important to have an off button to instigate a safe shutdown on a pi as just unplugging it might corrupt the SD card. Turning it on is just as simple as plugging it in - you need a bit more circuitry to do the full on/off thing (essentially you’d need an OnOff Shim) - and I doubt that’s on the pHAT BEAT.


#3

The button is for a safe shutdown that turns off the pi.

Once it is off the button can not turn on the pi because there is no power. To turn it on you need to unplug and plug in the micro USB cable.


#4

There is always a microcontroller added method. That it acts as a on/off gateway for the power and send a hi to a Pin on the pi that will preform a initiate softshutdown then giving a few moment cuts power. the ATTINY85 breakout is the size less then a U.S. 25cent piece and costs around 3 dollars. A small relay or regulator chip may or maynot be needed depending on the amperage draw required and to what limit the ATTINY can produce, There is an onboard voltage regulator on the ATTINY breakout. The Arduino mini or Micro would work too but is larger.
Many people use microcontroller aided shutdowns in projects so you should be able to find some varitions of this method. I was going to use one for a coin operated Retro-gaming cabinet.


#5

Thanks for the insight folks! I’ve a follow up question but I’ll create a new topic