The idea of the project came up in early 2016 as I
(Marc-Antoine) was working on a work-in-progress
(WIP) project named dlibox but only in the
summer of 2016 I saw that there was real value into making the Hardware
Abstraction Layer (HAL) a real project. The working name of the project was
pio but everyone agreed it was a bad name. :)
The first first commit as a separate git repository was on September 28th 2016 but the code had been worked on from within the dlibox repository back to August 2016. There was already the core concepts of automatic host detection and registered drivers, separation of HAL interfaces, device drivers and host drivers.
As Thorsten said, the library has probably been rewritten 10 times since then. :) For a long time I delayed making the project public as I thought " as long as the library doesn’t have users, I don’t mind making breaking changes “. 💣
In April 2017 the github repository was made public but not marketed at all as I still felt a lot of things weren’t right in the designs. Albeit a few weeks later it was listed on opensource.google.com and people discovered the project.
A year after coming up with the initial core design, v1.0.0 of periph was tagged on August 10th but v2.0.0 is getting released as many design elements were fine tuned…