5 ms·
Common misconception: USB Power Delivery is not what the RPi4 is doing. The base Type-C spec provides the schematic for analog signaling of either a 5V/1.5A or
by brandmeyer 7y ago
Common misconception: USB Power Delivery is not what the RPi4 is doing. The base Type-C spec provides the schematic for analog signaling of either a 5V/1.5A or 5V/3A state. USB-PD uses a much more complex digital signaling method across the CC lines, and is its own separate spec.
- baybal2 7y agoYes, it is not a PD. I am talking specifically about the case of doing USB fast charging aka USB PD, which is much, much more complex
- brandmeyer 7y agoThe entire USB power situation is complex. Lets see, there's pre-enumeration classic 5V/100mA, post-enumeration 5V/500mA, a host of proprietary signaling methods for additional power, the more or less de-facto BC 1.2 method for extra power, Type-C analog signaling for 5V/1.5A or 5V/3A power, and USB-PD digital signaling. Oh, and there's also Type-C VCONN power in addition to VBUS power. The irony in all this is that Type-C analog signaling was meant to greatly simplify the market situation and UX well above and beyond what happened in the micro-B charger world. And it is simpler. RPi4 just goofed in their implementation.