Version 4 of the Raspberry Pi, which was launched last year, is now said to be compatible with a larger number of USB-C adapters. According to The Register the Raspberry Pi Foundation assumes that the handicraft computers with a correspondingly modified construction plan are now available to customers. This was confirmed by the head of the foundation, Eben Upton, at the request of The Register. The previous configuration meant that power supplies with so-called active cables could not be used.
After the problem became known in July 2019, Upton gave the impression of downplaying the bug. "That means (the Pi) can practically not be powered by a Macbook charger, so if you have a nice smart charger and a nice expensive USB-C cable, chances are your charger doesn't have the Raspberry Pi powered "he said in a video interview.
However, it remains unclear whether and how potential buyers can recognize whether the problem with a newly ordered copy has actually been resolved. According to Upton, further changes were made to the board layout, for example to prevent unwanted solder bridges during production. The latest revision code with revision number 1.2 will be from the Foundation With "C03112" specified. However, users report in forumsthat the error had not yet been corrected for such copies purchased in November 2019.
An active cable has already integrated two Ra. (Image: (Image: Scorpia)
After the USB-C error became known, the Foundation was accused of not having delivered the Raspberry Pi 4 in accordance with the standard. The problem was caused by a lack of resistance. The USB-C connector requires two resistors instead of just one. In the Raspberry Pi 4, the resistor R79 was previously connected to Configuration Channel (CC) 1 and to CC 2. The problem with an inserted active cable with an E-Mark chip is that an additional pull-down resistor (Ra) is integrated in the cable. In combination with the pull-down resistor R79 (Rd), this results in a total resistance of 836 ohms on both channels.
The charger interprets these two values according to the USB Type-C standard (PDF) as if the Pi was an audio adapter that does not require a power supply. Therefore, the craft calculator is not supplied with power. Active cables are often required for power delivery power supplies with an output of more than 60 watts and a current of 5 amperes. Typically these are notebook power supplies.