What's the difference between ROCK 3A and 3B?
- 3A and 3B comes in different form factor, 3A is credit card size while 3B is 2.5inch SBC, gives more features and provides other advantages such as heat dispatching. Check hardware revision page for the detail difference.
Why doesn't ROCK 3A boot ?
- Check the following one by one.
- Power supply
- The ROCK 3 is powered by Type-C port and has a wide range of input voltage, from 9V to 21V. ROCK 3 supports USB Type-C PD 2.0 with 9V/2A, 12V/2A, 15V/2A and 20V/2A. Besides, the Pi supports QC 3.0/2.0 with 9V/2A and 12V/1.5A. The Type-C cable you using needs to support data communication. We call it USB Type-C charging data cable.
- Short-circuit the FSPI_CLK pin and GND pin to make SPI Nor flash unavailable.
Please note that you should short-circuit pin#1 and pin#2 always when spi nor flash is not used. Like the yellow left hat.
How "plug n play" is the CM3 with the Raspberry compute module?
- For compatibility of Radxa CM3 with Raspberry Pi CM4, most high speed buses just works such as USB, MIPI, PCIe etc. For the GPIO, since the pin mux is not identical, we can only be compatible with the primary alt function of Raspberry Pi CM4.
Radxa APT public key is not available
- When I try to run apt update, i get following error:
$ sudo apt update ... Err:21 http://apt.radxa.com/bionic-stable bionic InRelease The following signatures couldn't be verified because the public key is not available: NO_PUBKEY B99C4BEFEC47E96E Get:31 http://ports.ubuntu.com/ubuntu-ports bionic/universe Translation-en [4941 kB] Get:32 http://ports.ubuntu.com/ubuntu-ports bionic/multiverse arm64 Packages [126 kB] Get:33 http://ports.ubuntu.com/ubuntu-ports bionic/multiverse Translation-en [108 kB] Reading package lists... Done W: GPG error: http://apt.radxa.com/bionic-stable bionic InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY B99C4BEFEC47E96E E: The repository 'http://apt.radxa.com/bionic-stable bionic InRelease' is not signed. N: Updating from such a repository can't be done securely, and is therefore disabled by default. N: See apt-secure(8) manpage for repository creation and user configuration details. ...
The reason is the public key used before is expired. You can execute the following command to get the new available.
sudo apt-get install -y wget export DISTRO=bionic-stable wget -O - apt.radxa.com/$DISTRO/public.key | sudo apt-key add - sudo apt-get update