I picked up a Raspberry Pi 3 B+ to run OctoPrint on my Prusa Mk3s. I'm attempting to hardwire to the Mk3's Rambo board (5v) but I hear the Rambo board may not supply enough power to feed it directly (without using a dedicated separate power supply). The Rambo board can supply enough power for the Pi 0w.
I researched power consumption and it appears the Pi 3B+ uses about double the power of the 3B (690mA vs 350mA). For ease of reference the Pi 0 w uses 230 mA.
The article I'm going by says the main reason for the additional power consumption when comparing the 3B+ and the 3B is due to the newer gigabit lan chipthe new Gigabit LAN chip. This is the article: https://raspi.tv/2018/how-much-power-does-raspberry-pi-3b-use-power-measurements
My thought process is that if I turn off some of the 3B+'s hardware, such as BT and the new gigabit LAN, it should use less power (closer to 3B or even 0 w power levels ideally per the above link).
I THINK I need to add a few lines of code to the config.txt file to turn off some hardware that's not necessary for OctoPrint. Is that correct? If so, can someone chime in on what lines of code I should add to turn off some of the hardware? I think I can turn off BT and the LAN. Anything else? I just need the wifi on of course to allow OctoPrint to work. I will try to do some before/after power consumption measurements as well (while using an dedicated power supply for now to not damage the Rambo board).
As another way to reduce power, what line of code can i use to underclock the Pi3 B+ in addition to turning off some unused hardware capabilities.
My main goal is to switch off enough unused hardware so that the Pi 3B+ runs at similar power levels as the Pi 0 w (which I started with but I'm abandoning for this project due its inadequacies) and power the 3B+ directly with the Rambo board without an external/dedicated power supply. The main accessory I plan to run off the Pi 3B+ is a web cam along with a few plugins and I MIGHT add a USB light as well, but that's a later phase of this project.
Thanks in advance