H bridge with MOSFETS and PWM input

You need to setup the MOSFETs first. By default, the MOSFETs have 1/3um channel width. The simplest thing to do is to max it out.

Hey thanks! Now check out the wicked shoot through.

It's looking better now...

Now I'm working on how to switch only the low side mosfets with the PWM signal for motor speed control. I can have separate outputs from the arduino drive the high side on or off (using the BJTs) depending on the desired direction of motor spin. This also has the added bonus of (almost) eliminating shoot through. I have specific low side mosfet driver ICs through which the PWM signal controls motor speed. I haven't yet worked out how to simulate this effectively with EC. Also I've had some trouble with EC not being able to find the solution after I saved the circuit. For now, connect and switch on the logic signal on the side opposite to the direction the 3 way switch is pointing.

Actually, you need to start the sim with both logic inputs switched off for it to work.