Updated Variant PWM (markdown)

Variant-PWM.md

@@ -10,7 +10,11 @@ DEBUG_SERIAL will be automatically enabled on the opposite cable.<br>
 * Connect your receiver VCC to 3.3v from programming port, 5v from hall sensor cable, or a voltage regulator, ⚠️ Red wire from sensor cable delivers 15v !!!
 * Connect channel 1(steering) of your receiver to blue wire and channel 2(speed) to green wire of the cable selected in config.h
 * Connect the receiver to ground, ⚠️ On some boards, the black wire is 15v !!! Check with a multi-meter to make sure 15V and ground are not swapped
-* PWM is highly prone to noise : keep cables short, use 100nf capacitors, use shielded cable, use ferrites, stabilize voltage
+
+As the speed/load increases, there can be a lot of noise in the PWM signal, triggering unwanted movements :
+* Keep cables short, use shielded cable, use ferrites, stabilize voltage
+* You can scratch the pcb and solder 100nf capacitors to ground, that will act as a RC filter and reduce the signal noise  
+<img src="https://user-images.githubusercontent.com/20670049/166141871-08b8fc3e-dd4c-4704-8576-0e055b6fabee.jpg" width="200">
 
 ## Transmitter configuration:
 * Assign desired joystick to channel 1(steering) and channel 2(throttle)
@@ -23,4 +27,5 @@ If the board is [beeping](https://github.com/EmanuelFeru/hoverboard-firmware-hac
 * Make sure you are using the sensor cable(left=CONTROL_PWM_LEFT or right=CONTROL_PWM_RIGHT) selected in config.h
 * You might have a defective input, because of a fried resistor or MCU pin (e.g. [issue](https://github.com/EFeru/hoverboard-firmware-hack-FOC/issues/244)), you can configure the firmware to work on the other cable
 
-PWM is highly prone to noise : keep cables short, use 100nf capacitors, use shielded cable, use ferrites, stabilize voltage.
+If you get unwanted movements, check the wiring section.
+