Soldering Advice

[Bryan Mayland]

In the event that his 3.3V regulator has gone missing, is there any harm in using the 3.3V from the RasPi to provide 3.3V, like the old HM 4.0 boards did?

Yeah it is fine, but it is a little noiser due to it being a switching regulator. It was pretty insignificant, but the reason we don't use the Pi's 3.3V is just because it confused people about if they should install the HeaterMeter regulator or not so now it is disconnected on the circuit board from the Pi.