Interfacing switched resistors to an ADC input of a microcontroller
Using pull down resistors, you can get the following ...







simulate this circuit &ndash; Schematic created using CircuitLab

As the resistance of the ADC is confirmed as 2.12k, with the module removed, you get more or less full scale out of the ADC. With the module in circuit, you can switch between 0, 20%, 40%, 60%, 80% and 100%.

With your schematic that uses 2 more resistors, you get 45% of FSD with the module absent, then switch between 45%, 48%, 50%, 55%, 64% and 96% of FSD. Is that some particular non-linear law you want to achieve?