On Thursday, September 26, 2019 at 5:09:06 PM UTC-4, [email protected] wrote: > > Hi Guys, > > I am having some strange things going on with voltage levels and voltage > drop. > > First I noticed issues when powered from my MacPro, If I loaded the cpu > then the board could reboot, it could also get in a state where it needed > multiple reboots to get started. > > So I connected up to a 2.5A USB supply and this issue goes away. > > Another issue I am seeing though is I am only getting 4.6V on SYS_5V. I > have connected a BBB to the same supply and see 5V on SYS_5V. > > Also under cpu load SYS_5V drops to 4.3V. > > When powered from the MacPro SYS_5V is 4.3V and drops to 4V under load and > reboots. I tested a BBB connected to the MacPro and only get 4.7V on > SYS_5V. >
This much drop on SYS_5V is certainly unexpected. Do you have some kind of load on it or just the probe? BeagleBone AI should peak out about 1.8A (9W) under full processor/memory/flash load (including DSPs/EVEs/etc.). I don't know what your MacPro is outputing. 5W (1A) is much more typical. I find something like https://www.amazon.com/Satechi-USB-C-Power-Tester-Multimeter/dp/B01MT8MC3N/ to be really useful for monitoring the current consumption and voltage. Which port of your MacPro are you using and is it actively connected to a power source (not just battery)? > > Also when connected to the power supply VDD_5V is only 2.16V. > On BeagleBone AI, VDD_5V is input-to-BeagleBone-only, so the voltage really isn't of interest. > > Has anyone got any idea what might be going on here? > > Many thanks > > Andy > > -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/beagleboard/00530837-903f-4622-b62f-c4258b2df8cf%40googlegroups.com.
