First is to connect the LED light string, and the PIR motion sensor to the Seeeduino Lotus board. The Seeeduino Lotus includes the same interface as grove base shield, so we could easily plug in everything. However, since the PIR motion sensor is not a grove interface, we need to do a little hack.
The PIR motion sensor act as a digital input module, so the better way is to cut out a grove wire, and ensure to connect VCC, OUT, GND to VCC, D4, GND. The LED string light is simply connected to D5.
Both the PIR module and LED string module are easy to work with. PIR uses digital 0/1 input, but the LED string we want to implement a breathing light effect, so we need to choose D5 (PWM) port.