I wanted to get some feed back on a PWM motor controller I've been working for a 30W 12V motor. I got the Idea after seeing that 555 timers could be used for PWM and learned about the LM3914 so I wanted to combine the two. The P-Channel MOSFET is for reverse polarity protection. I don't have any official education in electronics/circuit design (chemical engineering student) besides what I've learned on my own and looking at schematics online so any advice on good practices is greatly appreciated. I tried to use a low-pass filter on PWM signal to convert it to an analogue signal for the LM3914 to read. My goal is to use the bar mode to show it's speed, but I'm not completely sure if I've wired it correctly.

 

My goal is to use the bar mode to show it's speed,

That will only give a rough indication of motor speed, since the speed for a given motor voltage is greatly affected by the motor load.

For accurate speed indication, you would need to use a sensor (magnetic, optical, etc.) to detect the motor shaft rotation speed.