A few days ago the new version of the Raspberry Pi 4 was announced, news that was unveiled here on the blog, how will you know this new version of this unique board retains the same appearance and starting price as its predecessor ($ 35) for specs that can't help but notice the leap made compared to previous versions: up to 4GB of RAM (four times more than any previous Pi, faster processor and GPU, faster Ethernet, Wi-Fi network dual band, double HDMI outputs and two USB ports 3.
Also, the Raspberry Pi 4 it is the first computer in the Foundation's catalog equipped with a USB-C connector for your power supply. This is also where there is bad news.
The USB-C port dedicated to the supply of electrical energy necessary for the operation of the computer, It is not compatible with any type of cable.
Well recently Eben Upton, one of the co-founders of the Rasbperry Pi Foundation, confirms the information.
“The new Raspberry Pi is equipped with a USB Type-C connector for power and some users complain that some chargers do not work with it (including MacBook chargers).
Some have speculated that this is due to a manufacturer limitation in the power supplies, but in reality this is due to a design flaw in the USB connection. The root of the problem is the presence of a pull-to-ground resistor on lines CC1 and CC2 of the USB Type C connector, "he explains.
Raspberry Pi 4 partial diagram.
“With most chargers this will not be a problem because the base cables use only one DC line and as a result the Raspberry pi is correctly detected and powered. The problem is with electronically marked cables that use both DC connections, "he adds.
A design problem that they did not contemplate
In the current state, using a USB Type-C cable with charger will make the Raspberry Pi ID detect it as an audio accessory and not a power source, which will bring the power to provide no power.
The Raspberry Pi co-founder said that smart chargers with an electronically marked cable "An e-marked cable" will incorrectly identify the Raspberry Pi 4 like an audio adapter and will refuse to provide power.
That is why for the moment the Raspberry Foundation recommends that Raspberry 4 users use the cables they use to charge their smartphones or tablets, since most of them are not "e-marked" and they will not have any problems.
Also consider using a power supply that can supply the 5.1V / 3A that the board needs.
Google's Benson Leung has spoken out on the matter and accuses the Raspberry Pi designers of non-compliance.
The Raspberry Pi team made two critical mistakes.
The first is that they designed this circuit themselves, perhaps trying to do something clever with current level sensing, but they didn't do it correctly.
Instead of inventing circuits, hardware designers should simply copy the USB-C specification.
The second mistake is that they haven't really tested their design with different types of cables. For example, every MacBook has been equipped with a USB Type-C cable since 2016. "
After this bug reported by many users The Raspberry Foundation announced that a corrected version of the Raspberry Pi 4 is on the way.
This design flaw is the second problem a Raspberry Pi Foundation product has exhibited in recent months.
Since in August of the previous year, the Foundation launched the Rasperry Pi Power Over Ethernet (PoE) HAT. As with USB-C, there were power issues with this expansion card.
For those who do not have a different USB Type-C cable to the "e-marked", lThe only option is to buy the official power supply $ 4 / £ 8 Raspberry Pi 8.