argen96

@Tomek51 Regarding klipper and rk3318/rk3328. I have done this setup with an rk3318 box and this armbian distro. In terms of performance it works fine. I also have a webcam and stream over the network with gstreamer. The comment I could make is be prepared to spend time (If unlucky) in setup and working around hardware bugs/issues. It is not like a raspberry pi where you plug it in and it just works. For example I boot from emmc and that works intermittently, about 50% of the times I need to go and unplug/plug back in. If booting from sdcard it works always so I will do a mixed kernel boot from sdcard and have a link to the root mount on internal emmc. These manufacturers don't have a standard bill of materials so for example the wifi chip that will be on your box will be unknown until you get it. In my case it was version of wifi chip that needed special modification of NVRAM settings and I found out about this from another user in the forum a few months after I had the box. On top of that you will be working with other issues related to the 3D printer so adding uncertainty with your server may not be desirable. Anyway, good luck!

Hi @jock & @hexdump Thanks for the reply, very interesting. The way I came to the fixed voltage conclusion was by looking at the reference design of the buck regulator IC on the board. There are 3 SOT-23 ICs marked "AS20B5". Here is what I found online: https://uccpd.com/article/97.mhtml Then I probed on the inductor with a DMM to measure the output voltage. In the reference design, the regulator output voltage is set by a voltage divider relation between R1 and R2. However, you may be right, if the circuit on the board feeds the output of RK3318 PWM into that resistor network, then I guess the SOC could in effect modify the output voltage by using its PWM controllers. Chinese designers come up with some clever cost cutting ideas, would be great. I don't have schematics, actually could not even find the datasheet for RK3318, I assume it is an RK3328 with 100Mbps ethernet which is the only difference I found. If you have a dts/dtb file for current kernels on similar boards I would love to give it a try. Thanks, Jose

I reply myself , for the record in case someone has the same board / issue. My PCB has a black solder mask and is marked in silkscreen as "RK3318_V1.2" . Upon inspecting the PCB I see that it does not have a proper power management IC. Instead it has 3 discrete switching regulators which output 3.3V, 1.18v and 1.15v respectively. These regulators have a fixed output voltage set by resistors so the 'dynamic' voltage frequency scaling through 'operating-points' is out of question. However throttling the CPU frequencies may be possible if not pushed beyond the limit set by the supply voltage. I will keep researching if anyone can point me towards some relevant info I would appreciate it.

Hello everyone, I have an rk3318 h96 max , 2gb, 16gb configuration. I've followed installation but couldn't get frequency scaling working. (/sys/devices/system/cpu/cpu0/cpufreq/ is empty) I am wondering if anyone can confirm that it works with the latest images. If it does work maybe there is something wrong with my dtb file. Thank you! Regards, Jose