The long and winding road of Raspberry Pi 4

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 A new project requires a Raspberry 4. It should be easy to get it working, I thought. But as the devil is in
the details, my morning bumped into several major showstoppers:

  1. It turns out the new RPi4 comes with a micro-HDMI. That, of course, is not hidden information but something I should have paid attention to in advance, but I did not. So it was now when I realize it was not possible to use any display for the initial configuration of the board or for any of my tests. 
  2. I remembered that RPi's had a serial connection over the GPIO bus I could attach to. But it turns out that feature is now disabled by default on versions 3 and 4 of the RPi, as they use that hardware serial port for Bluetooth communications. It is possible to get it back with the enable_uart=1 line on /boot/config.txt
  3. Unfortunately, the brand new SD card I have got with the RPi4 did not work. I am not sure is was defective or whether it was damaged when trying to get it out from its packaging (Intenso brand in case you are wondering). So that was a no go. I got another card that, after using the Raspberry Pi Imager software to write the OS to it, burped a verification error, so it was again useless.
  4. I finally got a new SD card that was happily written and verified so I could boot the system. I am using a 3V3 serial to USB adapter by SILabs and, as usual, I connected it wrong, as I was not sure what policy RPi wires followed. It was in fact the popular one where they tag the TX output as such. So in order to connect to my adapter TX needed to be connected to RX on the adapter and RX on the Pi had to be connected to TX on the serial to USB adapter.
Finally, I was able to use the Putty serial terminal to access the RPi4 and, using the raspi-config tool to configure the wifi information plus enabling SSH communication (so I no longer need to be using the serial terminal). Mission accomplished, but not before wasting most of the morning.

Oddly enough, I am not able to see the boot messages on the serial console, but at least I can log into the RPi4 using SSH over WiFi after a reboot. Now I am able to do the tests I needed to do with that new board. 

The new USB-C power input seems to be a much better choice than the flimsier micro-USB of previous models, and the new power supply rated to 5V/3A feels solid and stays cool.

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