I've finally come to the point where I need to use an external brick to power my project. This isn't a surprise given the large 5v current (500ma) as well as the 3v3 @150ma
. I've got all pin jumpers set to VIO so to use the switching reg. I'm using pins 0-24 so these groups will probably need to stay @ VIO. I haven't moved these jumpers yet since I haven't found a need, haven't had a chance to mess with VGA or anything..
I've been testing things with ~40ma on the 5v rail, not sure the 3v3 draw. But after connecting the larger 5v draw, the P2 no longer responds. I haven't done much troubleshooting yet since I've been surprised things worked so far on the desktop's USB current alone. Like I said I have a 5v brick (phone charger) I plan on using as "supplemental" supply but I'm wondering if there's an edge-case that needs to be prevented?
I'm thinking the power up sequence should be
PC-usb -> P2-usb
and power down is
P2-usb -> PC-usb
but I'm not really sure? Sorry if this has been answered before. Thanks in advance!