The Grove port can be managed in I2C or GPIO way but not in Serial or Analog way. Please check the lines tipology of your Grove modules before use them.
To use the GPIO 44 and GPIO 45 lines as I2C bus insert this line in /boot/config.txt and reboot the Raspberry Pi.
#Set the I2C1 interface on GPIO44 and 45 dtparam=i2c_arm=on dtparam=i2c_arm_baudrate=400000 dtoverlay=i2c1-bcm2708,sda1_pin=44,scl1_pin=45,pin_func=6
Install the i2c-tools package:
apt-get update apt-get install i2c-tools
then check if your module is detected on the I2C bus by using this command:
i2cdetect -y 1
CM3-HOME-B - Home automation carrier board for Raspberry CM3L module
Motherboard designed to provide a reliable Home Automation solution based on Raspberry Pi CM3L industrial module