Minimal connections

This may be a stupid question, but what are the minimal connections required for a module to work properly ?

The manual says VCC, GND and DOUT, DIN, but I don’t have an UART; all I want to do is send command frames through WIFI, which works just fine while the module is attached to the dev board.

Once I put it on the breadboard with just VCC, GND and the PWM0 connected back to the devboard, the leds light up just fine, but it doesn’t respond to frames or send sensor status periodically (which I have configure it to do and it works while on the dev board).

Any help is appreciated. Thanks.

After reading the manual thoroughly, I think I figured out the cause :

To help reduce noise, we recommend placing a 1.0 μF and
8.2 pF capacitor as near as possible to pin 1 on the XBee

Placed an even bigger capacitor, and everything is working just fine.