Month: November 2020

Hot Raspberry Pi

Steven Guccione

My downstairs TV Raspberry Pi 4 started showing a little thermometer icon in the upper right corner while I was streaming some hi-def video. Turns out it was overheating, or close to it. I didn’t put the fan in since I put heatsinks on the processor and two other chips and didn’t think it was necessary. But I suppose under heavy use, especially streaming video, heat gets to be a problem. I snapped the fan in, plugged it in to the 5V on the header and the temperature quickly dropped 40F. Now I wonder if my WiFi problems on my desktop were heat related. Both my Raspberry Pi 4s are now on ethernet, so I’ve stopped fighting the wifi battle.

Raspberry Pi 4 Video

Steven Guccione

I decided to put a Raspberry Pi 4 on the downstairs TV, with the vague idea of watching streaming media. We already have an Apple TV and a Chromecast, but their mirroring is always more complicated and lower quality than advertised.

Getting set up was easy. Bought an 8GB CanaKit on Amazon and it arrived in one day. I used the default install of 32-bit Raspberian OS as a test, then installed 64-bit Ubuntu. The only hiccup was using 20.04 LTS, which didn’t come with an included user interface. No problem, I can install Gnome. Except modern Ubuntu servers seem to secretly do a security update in the background by default, which blocks any other updates or installs. Once I figured this out it was off to the races.

I went to YouTube for a video test and the results were disappointing. Slow, pixelated and choppy. I know the processor in the Raspberry Pi 4 has a pretty decent Graphics Processor (GPU) so performance should be better. A bit more Googling showed it needed to be enabled at the kernel level.

Some earlier postings showed how to rebuild libraries and the kernel, but that seemed like too much work. It did look like later postings using more recent kernels could enable the GPU with a single line in a configuration file and a reboot. I gave it a try, adding the lines below to the /boot/firmware/usercfg.txt file.

disable_overscan=1
dtoverlay=vc4-fkms-v3d

The first line just fixes the annoying black borders around the display and allows the full screen to be used at full resolution. I’m not sure why this isn’t the default. The second line enables the GPU. After a reboot you can tell if it works by looking at the Graphics field in the About page in Settings as below. The default (slow) software graphics interface is called llvmpipe. It should now say V3D, the 3D “Vulcan” graphics driver.

After this change video was smooth and fast, even in a browser. I was impressed. It also seems to help with regular desktop rendering. You may also need to do special enabling in applications such as Chrome and VLC.

Shaft Couplers

Steven Guccione

Got my little 500W motor for my riding mower conversion to electric. The good news is it fits in the space under the seat near the differential. My hope was that I would easily and directly be able to hook my motor shaft to the shaft of the differential of the mower. It might not be that simple. There is a whole catalog of shaft couplers out there but the particulars of both the motor shaft and the mower shaft might make this a non-starter. I’m not skilled or set up to do metal work so I’m searching around for the simplest way to do this. I could go with a belt drive which keeps the belt pulley for the differential in place, but I’ll need a belt pulley for the motor and probably another on a spring for tension. Or I could use the chain sprocket on the motor but I would have to fit a chain sprocket on the differential shaft. There might be an way to use the existing belt pulley as a plate and bolt it to another plate fixed to the motor. Need to think about it.

Downtown Walk

Steven Guccione

It was a nice day so we decided, for a change of pace, to go downtown, put on a mask, and walk around. The last time we had been downtown was in the early days of the pandemic. The road down was busy, but parking was easy. There was nobody around. Some construction workers, but basically a ghost town. Lots of places closed and even boarded up. Perhaps it looks different in the evenings or on weekends. Went home and made some chicken and egg ramen for lunch.