{c}

2022-10 ELEGOO Upgraded Electronics Fun Kit https://www.elegoo.com/products/elegoo-electronics-fun-kits-4-versions Manuals:

* https://www.elegoo.com/blogs/arduino-projects/elegoo-electronic-fun-kit-upgraded-electronic-fun-kit-tutorial
* http://69.195.111.207/tutorial/ELEGOO/05%20Accessory%20Kit%20Tutorial/09%20Electronic%20Starter%20Kit/E2&E3/Elegoo%20Electronics%20Fun%20Kit(No%20UNO%20Board%20Included)%20V1.0.19.09.10.zip

<Breadboard> power supply module MB‐V2:

* Input voltage: 6.5-9v (DC) via 5.5mm x 2.1mm plug
* Output voltage: 3.3V/5v
* Maximum output current: 700 mA

TODO center positive or center negative?

Does not come with <AC adapter>, getting this one: https://www.amazon.co.uk/dp/B08ZN476FW output: DC 9V 1A Power Supply Adapter, Plug 5.5mm x 2.1mm, Center Positive,B rand: Security-01, input: AC 100-240V 50/60 Hz, Cable length: 1.8m

<LEDs>:
* maximum Continuous Forward Current: 50 mA
* under 20 mA
  * Forward Voltage: 2.0 V typical, 2.5 V max

20 mA appears to be the typical operation. So with the 2.0 V drop on 5 V power we want a resistor such that:
$$
(5 - 2)/r = 20 10^{-3} \implies r = 150
$$

for the max 50 mA we would instead have 60 <Ohms>
