I've build a board with and ESP32 and a USB-C type connector with a FUSB302B Programmable USB Type‐C Controller.
I implemented the power delivery protocol and can do a successful power role swap between the ESP32 and a tablet. Upon connecting the tablet to the board, the tablet provides the power to the board and after a power role swap the board provides the power to the tablet.
But after the power role swap the tablet only draws 0.6 amps, and not the negotiated 1.5 amps. How is this possible?
During the power negotiation I send the source capabilities (5v / 1.5 amps), the tablet then requests the 5v / 1.5 amps. Then I accept the request and send a power source ready. (There is now a contract between them). But the tablet is only drawing the 0.6 amps.
I would expect that the tablet would draw 1.5 amps. If I connect the tablet to my laptop usb-c connection with power delivery, it draws the 1.5 amps.