Throw me Away

Cleaning out an entire business operation has led to a few discoveries.

Throw me Away... A bright yellow sticky on a laptop computer
Throw me Away… A bright yellow sticky on a laptop computer

Hidden caches of tools, bottles of unknown substances, pieces of strange equipment that even I struggle to identify, and so much trash… All of the stuff a couple dozen employees leave behind in five years of a busy algae-growing operation.

This included a stack of five laptop computers, two Macs and three pc’s. So one evening I handed off the Macs to my wife to check while I diagnosed the pc’s.

One Mac is toast, a cracked screen and damaged case, clearly dropped at some point. Checking the model and vintage, we find it is not worth the effort to fix… One for the bin. The second Mac is questionable, with a flaky charge port and dodgy WiFi.

The pc’s? One, a very low-end HP model seems fine.

The second machine, a more promising-looking Lenovo IdeaPad that is only a couple of years old. Opening the machine, stuck beside the trackpad, I find a bright yellow sticky note with large, friendly letters written in Sharpie… “Throw me Away”.

Hmmm… Maybe not.

Well? The machine boots easily enough, screen, keyboard, and trackpad are working just fine. I am presented with the login screen for an employee who left the company over a year ago. I cannot go further, Windows and the drive are locked down pretty hard.

This is not a real concern, I really do not want another Windows machine. I downloaded the latest version of Ubuntu and set up a USB drive. The machine boots just fine into Linux off the thumb drive. It took some command-line futzing and a fair amount of AI assistance to find the right Linux commands to wipe the hard drive. I cleared the encrypted Windows partitions and configured an Ubuntu install.

After waiting for Ubuntu to install, I found I have an operational laptop that seems to be in pretty good shape. I wonder… why the doomed sticky note? Was it the lockdown and encrypted drive that stopped anyone from re-using the machine?

Well? I need a reliable work machine, and Windows has become increasingly unacceptable over the years, time to get serious about Linux. I peel off the yellow sticky note and follow the instructions… I throw it away.

Raspberry Pi, Python and SPI

It has only taken me much of the day to get it working. Hours spent reading documentation, searching for postings on the same issue, ripping up the code and trying completely different approaches. Hours of frustration mixed with some solid learning.

Victory was seen in three bytes.

Three bytes shown on the logic analyzer display and in the Python console window. The same three bytes… The hardware and software agreed. The serial timing also looked great, chip select going low when it was supposed to, a 500kHz clock, all of the edges just as the data sheet specified.

Victory is connecting an eight channel A/D converter IC to a Raspberry Pi computer with the hardware SPI module. Four channels for voltages, four channels for temperatures. The project is coming along nicely. Will talk about what in a later posting. Meantime my thanks to Connor Wolf, Louis Thiery, and Brian Hensley. It was their method and SPI code that worked!

A small victory, another step forward, this is what hackers and makers do…

Raspberry Pi Data Acquisition
A Raspberry Pi computer set up with an A/D daughterboard