Hello forum,

I'm using Rpi CM4, Rpi Pico and LoRa system all powered using a Buck converter which will provide 5V output. Sometimes when I connect antenna to LoRa the whole system gets turned off. Though it is not repeatable, it is happening and I wanted to know why?

 

You will need to provide more information for people to be able to help you with your problem. For a start are all the power rails at the correct voltage when you say that your system shuts down. That should have been the first step in fault finding.

Les.

 

You will need to provide more information for people to be able to help you with your problem. For a start are all the power rails at the correct voltage when you say that your system shuts down. That should have been the first step in fault finding.

Les.

Yes all are powered by 5V and the whole system will turn off. The sequence of sub-systems turning on is Pico turns on when I press the power on button. Later, CM4 and LoRa will be turned on. When I connect the antenna when the device is on, the entire system will turn off from LoRa to CM4 to Pico and again when I press the power button everything works properly.

 

Based on almost no information provided, a reasonable guess is that connecting the antenna causes an increase in the current drawn such that the power supply voltage drops far enough so that the devices switch off.

NOTE: IF YOU WANT A BETTER EXPLANATION THAT IS LESS THAN A GOOD GUESS, YOU NEED TO PROVIDE MORE INFORMATION. I do not know what a Rpi CM4, Rpi Pico and LoRa system are, nor am I willing to research and find out. As I have often stated, I have no mind reading ability and so folks need to provide information so that others and myself can actually see what needs analysis.

 

Does your system have any floating reset pins?

I would suggest discharging any static charge you might be carrying on your body before connecting the antennas.

And of course, the obvious would be to not attach any antennas while the system is powered up.