PrimeWire

Isaac Asimov’s “I, Robot” and “Foundation” series are connected through his broader “Robot” and “Foundation” universes. While the “I, Robot” short stories were initially separate from the “Foundation” series, Asimov later integrated them, making R. Daneel Olivaw, a robot from the “Robot” stories, a character in the “Foundation” universe centuries later. This connection is solidified through the “Robots and Empire” novel, which bridges the gap between the two series by describing the settling of worlds that would later form the Galactic Empire in “Foundation”.
Here’s a more detailed breakdown:

Initial Separation:
The original "Foundation" trilogy (Foundation, Foundation and Empire, Second Foundation) was written as a standalone series, separate from the "Robot" stories. 

Integration:
Asimov later decided to link the series, particularly when writing the later “Foundation” books like “Foundation’s Edge” and “Foundation and Earth”.
R. Daneel Olivaw:
The robot R. Daneel Olivaw, introduced in the “Robot” series, appears in the later “Foundation” novels, appearing as a character twenty thousand years later in the Galactic Empire’s history.
“Robots and Empire”:
This novel serves as a crucial bridge, detailing how the worlds that would become the Galactic Empire were settled and how Earth became radioactive, which was a detail first mentioned in the “Foundation” universe.
Unified Universe:
By integrating the “Robot” and “Foundation” series, Asimov created a vast, unified “future history” encompassing his works.
Reading Order:
While the original “Foundation” trilogy can be read without prior knowledge of the “Robot” series, the later “Foundation” books, particularly the sequels and prequels, benefit from familiarity with the “Robot” stories, especially “Robots and Empire”.