Technology

August 31, 2018 3:24 pm Update

I have a simple solution to make America Great Again.

Just replace all the labels that say “Hertz” (International System of Units) with “Cycles Per Second” or “CS” (English Units). America resisted that change until the mid-1970s, even though 1 cycles per second = Hertz.

Indeed, well into the 1970s, American-made equipment was rated kilocycles and megacycles per second, even though that’s a mix of the International System and English Units.

Headless Raspberry Pi Setup – learn.sparkfun.com

Headless Raspberry Pi Setup – learn.sparkfun.com

I was thinking I needed some kind of portable screen and keyboard to use with my Raspberry Pi when I took it down to the library to download software for it. Then I thought about it a bit more, then said there is a simpler, more portable way to do this.

I could instead just use a ethernet-crossover cable, and ssh (secure shell) into the Raspberry Pi from my laptop. Then if I ran X11 over ssh, I could run everything through my laptop, including the graphical interface. Such an obvious solution!

Raspberry Pi

I got a Raspberry Pi 3B+, case and power adapter for $50 including shipping. It also comes with an HDMI cable. I have a wireless keyboard and MicroSD card I’m on using that with it. I wasn’t sure if the existing USB power supplies were beefy enough to power it so I bought one too. At least some of them would have worked others probably not due to voltage drop. While the Raspberry Pi is priced at $35 that’s before shipping and tax, and I needed a case to protect it. It arrived in the mail today.

I wasn’t going to buy it until I got the $50 rebate for my contact lens order. Then I decided I had the money to pay for it. I also decided I could make use it in several ways after reading up on it more on the internet.

First off, I could use it as a second computer when I was traveling for work in case my laptop was having problems. It’s not powerful enough to do mapping but it can do basic web surfing and office applications including the LibreOffice. With the lightweight window manager and MicroSD card providing solid state disk access it’s very quick.

At home I’m planning on using it primarily as a way to play back YouTube videos I’ve downloaded onto a flash drive. This way I can use my Bluetooth headphones which never work quite right with my laptop while watching videos. But I do need to access the internet to get some software updates, but I will have to do somewhere I can get wifi. For portability purposes I’m thinking about getting a small screen to use with it so it doesn’t always have to be hooked up to my computer monitor. It’s a full Linux based operating system so I can write whatever code and scripts that I like.

Third, I read the power specs more carefully and discovered that the power consumption wasn’t that bad for the Raspberry Pi – while they recommend a 2.5 amp 15 watt power supply to ensure ample power for all the ports, during ordinary operations it uses more like 700 milliamp or less based on my own metering of the usage. Roughly 3 watts not including the monitor. Sure that’s a lot more power than a Arduino Nano or ESP32 but I don’t expect this to be running 24-7. It’s a full featured computer that runs Linux and X11 not a microprocessor for driving specific applications.

It’s an interesting technology I want to play with more over the coming weeks. With an open source Linux based operating system, plus a full window manager, browser and a lot of IO pins there is much I can do with it.

August 27, 2018 2:56 pm Update

I noticed that 512 MB M.2 SSD drives are now in the range of $100. I’ve wanted to upgrade to SSD since I got my laptop during the end of 2016, so my laptop boots up quickly and loads applications really fast; I think I will come November.

August 23, 2018 11:18 am Update

I keep getting this phone call from a number that I don’t know. Never leaves a voicemail. So I decided to call from a different phone with caller ID blocked, and guess what, that number is “disconnected”. I am sure this must be a legitimate call. ☎️

August 20, 2018 8:28 pm Update

I learned a new handy thing today.

In BASH if you want to repeat the last command, just type !!

This is really handy when you forget to type in sudo to do something as root. For example:

apt-get update
sudo !!