The Raspberry PI 3 Plus came about out of a need to collect data from the weather station, and the solar panels and stuff it all in one database. Sounds like that should be easy for a guy like me who has been programming Microsoft SQL server off and on for 28 years. I must admit mostly off the last few years. What the heck, it sounds like a good winter challenge.
I envisioned the final product looking like this:
After discovering the PI does not have a hi-res graphics card we finally settled on what it could deliver. The picture is stretched, but clear.
You have to download the operating systems from raspberrypi.org The internet decided to die, fortunately we had two modems. The dead one, and the one we are using now. Seems the project is going well so far.
Athena downloaded NOOB’s for me along with Debian / Raspian Stretch. Who comes up with these names anyway. Once the PI was up, we connected two Exar corporation RS485 interface cables to two of the four USB ports on the PI, and to the EPEVER 4210 A Tracer MPPT chargers. To know if everything is ready for programming you go into the /DEV directory on the PI. In that directory you should find two files one for each charger. The file names should be TTYUSB0 and TTYUSB1. Instead they came up TTYACM0 and TTYACM1, which will not work with the MOBUS serial interface protocol that’s on the 4210. So as a good Windows guy would do, I went to Exar corporation to get the linux drivers. Found some, but the were a year out of date, and not compiled. After staring at them for a bit I found they were in “C” and a simple make command should be all that would be required.
On issuing the make command, I got no headers found! so I placed the build directory in kernel directory. Ran the make command again, and it said entering kernel directory over and over again until my 1GB ram chip crashed the command. I then created a 40GB ram drive (swap file) to use as memory, and issued the command again. The results were the same only it took about an hour to crash.
On further inspection, I found the files were meant for a 3x kernal, Raspian and Debian could not supply that. I then placed Ubuntu Mate on the pi. Was able to compile the code in a 3x kernal. On testing the Mobus calls, the serial ports would identify themselves correctly, my software could see them, but the scripts just timed out. After a few weeks of this, the Raspberry PI is vacationing in my desk drawer. The weather station, is just dumping files in a directory on my Windows machine.
Meltdown and Spectre vulnerabilities
Athena got a call from all her customers; Each lost at least one production computer. At first we thought it was a virus that wiped out some files and took the hard drive offline. We did some forensics and found out that a Microsoft update had occured right before she did a reboot. The customer had already done a reboot and repair. Her data was gone and had to be retrieved from backup. Don’t do the repair!
Solution that appears to work
Athena was helping the same customer when her computer suddenly rebooted, and came up asking to do a repair. We said no, and let Windows replace the startup files. This is an option under advanced in the Windows diagnostic screen. She removed the Microsoft update, I don’t know the update number. As of this writing, Microsoft is releasing a new update to remove the last update. We believe that anyone running the Intel chipset could have issues. The bug effects Linux, MAC, and Windows. We had one MAC with the same symptoms, but who knows the source on that one. Athena is not back logged on PC repairs. We are wondering if Microsoft and Intel are working together to spur the PC economy. We have customers calling us saying they bought new machines and need them setup. Athena is busy filling a contract for IBM, so work is stacking up.
Computers are driving me to drinking, someday it might be something harder than Mountain Dew, and it will not be long until Athena is drinking right along side of me. At least I’ll be able to claim that I am only a social drinker.
Have a good evening and a good night …