Seeeduino+Grove electromagnet

Hello - I am looking to control multiple electromagnets with a Seeeduino v4.2 board. The Grove electromagnet has a working voltage of 400 mA but the output of the Seeeduino board is only 40 mA. I am considering two options:

1. Using the DC outputs on the Seeeduino board to drive the Grove electromagnets. However, I can only control one electromagnet per board. I could use multiple boards.
2. Pairing the Seeeduino board with a SeeedStudio - Motor Shield V2.0 board - which gives me the capability to control two electromagnets. Is this option feasible or am I missing something?
   Any other suggestions? I am relatively new to all this and do not fully understand the nuances of electrical circuits.
   Thanks
   -Gaurav

Hello Gaurav! I’ll suggest you to use transistors instead. Use transistor as a switch. By using a transistor as a switch you can power your electromagnets from an external power source (eg. 9v battery). Connect the emitter of the transistor to the ground (Common to ext. source & Seeduino). The Electromagnet connected in between the + terminal of the source and collector of the transistor. Connect the base of the transistor with the digital output pin on seeduino through a 10k ohm resistor. Even the low current provided to the base would be enough to trigger your electromagnets.