Power management module

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yeah speeduino uses flexcan_t4 on teensy versions, but they use STM mcus as well, im on their discord as well
 
Not trying to build an ecu. But pmu, i would like to build some pcb to switch on lights etc using can bus. I would not like to use fuses in the car, so i would need to monitor current going through mosfet's. What mosfets would be suitable for this?
 
i am using an esp32 with mosfets being commanded by teensy over CAN. So teensy can control the 10 gpios currently connected to the esp32. i also posted a sketch for it on github. mosfet boards you can get from tindie unless you want to build a circuit yourself
 
i am using an esp32 with mosfets being commanded by teensy over CAN. So teensy can control the 10 gpios currently connected to the esp32. i also posted a sketch for it on github. mosfet boards you can get from tindie unless you want to build a circuit yourself

Not possible to connect mosfets directly to my teensy?
 
Not possible to connect mosfets directly to my teensy?

With most mosfets, no, do not connect the mosfet gate directly to a Teensy pin. At the very least, you need a resistor like 150 or 330 ohms, because the mosfet gate acts like a capacitor. The resistor limits the current to a safe maximum when the voltage changes. 330 ohms limits to 10mA which is safest.

There are 2 common problems.

1: Teensy only gives 3.3V output. Many mosfets do not work at all with only 3.3V at their gate, or perform so poorly they're unusable. Many of the types meant for controlling large loads are meant to have 10 volts minimum. Very few (especially high current types) are designed to work with only 3.3V.

2: Charging the gate takes time. If using a 330 ohm resistor, this may be too slow, especially if higher frequency PWM is used. Generally, the higher mosfet's rated current, and the lower the voltage needed at the gate, the more capacitance it has. This is why so many are designed for 10 volts - it allows a much lower cost mosfet.
 
As paul said you need a proper circuit with logic mosfets and series resistor to protect the pins. You shouldn't be driving loads only applying a signal where the mosfet or relay takes care of the load end. czhlabs has relay boxes designed to connect directly to the gpios that also include series resistor built in the circuit.
if you want well designed mosfet boards check out tindie
 
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