All measurements at 5 VDC. Raspberry Pi 2 has Wi-Pi (USB Wi-Fi dongle).

• mBot idle (with LED matrix, line following, etc): 0.15 mA
• mBot motors running (@ 100 out of 255): 0.21 mA
• mBot motors starting/spinning up: 0.27 mA
• Pixy camera starting up: 0.25 mA
• Pixy camera idle: 0.18 mA
• RPi2 starting up: 0.38 mA
• RPi2 idle: 0.28 mA
• RPi2 Wi-Fi data transfer: 0.38 mA to 0.44 mA
• RPi2 capturing video: 0.46 mA (note: CPU is idling)
• RPi2 capturing video and Wi-Fi data transfer: 0.66 mA
• RPi2 one CPU thread busy loop (25%): 0.31 mA
• RPi2 four CPU threads busy loop (100%): 0.41 mA
• RPi2 CPU 100%, video and Wi-Fi transfer: 0.76 mA

All up: RPi2 0.76 mA + Pixy 0.25 mA + mBot 0.27 mA = 1.28 mA total