1.0 PCB Self-Heating

The PCB has ~3 degrees C of self-heating.


Putting the PCB in an enclosure will make the effect worse.

The primary source of heat is likely the LDO regulator. (These are inherently inefficient because they burn off excess voltage as heat.) The next suspects are the LEDs (LEDs were blinking in this case) and then the MCU.

There are a few options here:
1. Move the sensor to the corner of the board
2. Add cutouts to the ground plane around the sensor to reduce sensitivity
3. Switch the LDO regulator for a switching regulator.
4. Lower the clock frequency of the MCU
5. disable the LEDs during normal operation.

>[!NOTE]
> It's worth confirming that the regulator is the problem using a thermal camera.

### Regulator Option

The RT6150B is a good candidate for a new power supply option. It is 90% efficient in the operating region we will use, and it's identical to what's used on the Pico 2 board. See [Pico 2 Datasheet](https://datasheets.raspberrypi.com/pico/pico-2-datasheet.pdf). It will cost more board space, though.