Raspberry Pi Compute Module 4 is one of the best platforms for hobbyist engineers and makers. A little while ago, we have covered the smallest carrier board at the time, however, a new contender from @arturo182 has just appeared, and it carries the name "Stick".
According to the Twitter feed of Sweedish engineer @arturo182, who is the founder of Solder Party, we are today blessed with the unofficial record for the world's smallest Raspberry Pi Compute Module 4 carrier board conveniently named The Stick.
The Stick breaks out a USB-C connector to power the Compute Module 4 and features a pinout for a few GPIO pins like GP2, GP3, GP8, GP9, GP11, GP14, GP15, alongside the regular GND, 3V, and 5V pins. These pins correlate to I2C (GP2 and GP3) Serial Peripheral Interface (SPI, GP8, 9, 11), and UART Tx and Rx via GP14 and 15. The Stick only connects to one of the Compute Module 4 100 pin high density connectors, so chances are that we will not have access to every feature of the CM4, but for basic use this is plenty of IO.
The diminutive size of the board brings one problem. A lack of any solid mounting mechanism besides the pinout connector, which provides a friction fit but can easily be removed. An addition of M2.5 screw holes would be a nice option for additional security, something that is present on the former smallest breakout board, MinCab.
As the board is just a fun project, the maker has raised a question of "Should I sell these", and if there is enough interest, he could start batch production. So be sure to show your interest in the Twitter thread and post your thoughts there.