this is my easy project to build shield for arduino mega (due is easy update)
options:
sensors ITGS3205 ADCL345 HMC5883L // BMP085
current sensors acs758 100A/200A
voltage sensor
wireless module nrf24L01
bluetooth module hc-05/06
wifi module esp8266 configured in transparent mode
optocupler for motors and servo
optocupler as logic level converter for nrf24L01, hc-05 and esp8266
5v board separate from 5v esc/servo
5v / 3.3v with high capacity tantalum capacitor
beta version is working
https://youtu.be/OpTypWmU9sY?t=84
first image of project: