@@ -157,7 +157,7 @@ Now add a reset button. Suitable value for capacitor is found in the MCU data sh
### 13) Power LEDs and test points
In order to see that your system is correctly powered, it is recommended to add test points for easy probing, in the form of exposed pads on the board. It is recommended to use a pin header footprint for GND test points so you can easily clip the scope probe's GND alligator clip to it. Place at least one GND clip for each subcircuit block on your boards. You don't need to stuff them with pins by default during assembly, but it is nice to have the option to add those in when troubleshooting.
In order to see that your system is correctly powered and to have easy access to probing your signal lines, it is recommended to add test points to your board, in the form of exposed pads. Preferrably se a pin header footprint for your GND test points so you can easily clip the scope probe's GND alligator clip to it. Provide at least one GND test point for each subcircuit block on your boards. You don't need to stuff them with pins by default during assembly, but it is nice to have the option to add those in when troubleshooting.
It is also recommended you add LEDs to your power rails so you can see they're powered up correctly. You can use an LED such as [this red one](https://www.elfa.se/en/smd-led-645nm-0805-65cd-30ma-kingbright-kptd-2012surck/p/30118951), together with a suitable current limiting resistor. The forward voltage drop of a red LED is around 1.8V, aim for a forward current of about 2mA. You can use this [LED calculator](https://ohmslawcalculator.com/led-resistor-calculator) to calculate suitable resistor values for your LEDs. Use resistor values from the E12 series.
