@@ -151,9 +151,9 @@ Once you have added the 1.9v power supply you can add a new power net, and conne
Now add a reset button. Suitable value for capacitor is found in the MCU data sheet.
### 13) Power LEDs and probing pins
### 13) Power LEDs and test points
In order to see that your system is correctly powered, it is common to add both probing pins/pads and LEDs. You can use (_HA_) and a [led caluclator](https://ohmslawcalculator.com/led-resistor-calculator) to design suitable current limiter. Use values from the E12 series.
In order to see that your system is correctly powered, it is common to add test points for easy probing. 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 [](https://www.elfa.se/en/smd-led-645nm-0805-65cd-30ma-kingbright-kptd-2012surck/p/30118951), together with a suitable current limiting resistor. 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.
### 14) SPI
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@@ -176,7 +176,7 @@ Decide on which pins you want to use, and connect the PMW3389 to your MCU. You c
Until now you have used the USB only to power the system, but you will need to add data lines +D/-D as well for communication. Check the data sheet for specifics.
You may also want to protect your system from ESD (Electrostatic discharge). To that end you may optionally add protection circuitry (_HA_).
You may also want to protect your system from ESD (Electrostatic discharge). To that end you may optionally add [ESD protection circuitry](https://www.elfa.se/en/esd-protection-diode-bi-directional-25v-sot-23-st-usblc6-2sc6/p/30034148).
