How to shut down the RPI4 for a certain time or prevent it to turn on power on booting

Question

For my project, I access the RPI remotely. The RPI continuously powers sensors over its 3.3vdc rail. For testing & troubleshooting, I would like to cut current to those sensors for some time.

After searching, I don't think there is an easy way without additional hardware, a timer or anything like that to turn off the raspberry pi for a certain time, let's say 30minutes.

Another fix for my problem wold be to prevent the RPI from powering up it's peripherals.

I know that the RPI is using an MXL7704-P4 for power management. Does it always output the 3.3V when the source is connected or just after booting?

Answer 1

You have asked a number of questions.

To answer the last it is possible to get the Pi4 to shutdown to a very low power (a few 10s of mA). The PMIC (and thus 3.3V) off. Indeed this is how it initially worked (until the luddites convinced RPT to change it) but it is simple to restore this.

It is simple to program shutdown based on timer or command.

You would need some external hardware to reboot.