My philosophy for Carl is to manage load to find limits and stay out of trouble. Perhaps, if you want to try really pounding a Pi4 get another one and put it on your desk. The GoPiGo3 board will not supply enough 5v to drive the Pi4 to the max, but will serve up enough for exploring lots of topics.
You can also just add a usb-c powerbank to the Pi4 power connector and use the existing batteries to power the GoPiGo3, no?
I really want to post a picture of Charlie connected to a 12v car battery with huge-honkin’ jumper-cables as a goof. Not really connected, but to make it look like I’m powering Charlie off a gigantic DieHard!
Put Charlie up on a pedestal, strap a multimeter between the battery and bot, and start plugging and unplugging, driving and not, sensing and not, speaking and not, etc.
Interesting observation:
I have Charlie sitting on my desk with a fresh set of batteries installed. With that, the battery voltage returns 9.6.
If I attach a True and Authorized Raspberry Pi-4 Power Supply to the USB type-C connector, the “measured” battery voltage jumps to 18.something!
Obviously, the battery voltage hasn’t jumped by that amount. I suspect I’m going to have to take a look at the GPG driver board schematic and propose a hardware change.
. . . has a link to the voltage regulator data-sheet, and according to that, the absolute drop-dead max voltage is 45 volts for the garden-variety version.
The DMP3017SFG power switch has a 30v breakdown voltage and who knows what the caps are rated at, but Matt didn’t seem to be too worried about being slightly over the 14v limit.
Definitely possible. I have to look at it myself - when I get back from visiting friends.
I’m seriously considering unsoldering that cap and moving it to a different place on the PCB attached with a twsted pair so I can attach my Pi-4 without having to completely re-engineer the 'bot.
