Hi, all. I’m new to GHI and want to use the Cerb40 in a project. It seems like an interesting low cost controller, but I’m having trouble identifying the power requirements.
The schematic shows a LM1117 voltage regulator supplying 3.3 V, but it is attached directly to the USB port as well as a pin marked VBUS on the schematic, and USB on the silkscreen. There is a VCC pin, but it seems to be VCC in relation to the micro, not the system. Then there is a pin marked VBAT directly attached to the micro. This is a bit confusing when there seems to be no datasheet available for this system.
When not powered by USB, can I assume I use the VBUS pin for power? Does it support the entire 6 to 12V range of the LM1117 regulator? What happens when I plug a USB cable in and VBUS is at 12V?
Thanks in advance.