Sunday, September 27, 2020

A Simple Public Safety Radio Scanner with the Raspberry Pi - Part 2 - Building an Amplifier

Amplifier sketch

Now that I have my Raspberry Pi pulling in the local radio stations and playing some tunes, I really needed to find a way to have the music play at a volume that an average human can hear. 

The simplest way to do this is to plug some sort of amplifier into the phone jack of the Raspberry Pi and have it put the sound out to an external speaker. 

There are a lot of pre-built circuits out there that you can simply buy and plugin. While that can be a very easy solution to the problem, it would be a strangely unsatisfying thing to do from my point of view. I have never really built an amplifier before. since I am just looking to have something that can broadcast public safety transmissions and I don't really care if it was high fidelity quality sound I figured that this would be a perfect time to learn how to build one. 

Sunday, September 20, 2020

A Simple Public Safety Radio Scanner with the Raspberry Pi - Part 1 - Receiving Signals

All the bits needed to make a radio scanner

As I may have mentioned previously, along with a fondness of making sawdust, I am also a bit of a radio nut.

As I sit here typing out this post, I have my trusty HF Amateur Radio transceiver (an Icom 718 if you're curious) and my digital VHF scanner (a Grecom) keeping me abreast of what's going on, both locally and internationally.

My scanner in particular is quite busy since it is always checking the frequencies for a large number of public safety agencies in my area. While I certainly enjoy being in the know of what's going on in my local area, I do find that I may miss something that has happened closer to home because the scanner is busy telling me about something happening over in the next county.

This is particularly true about activity that involves my local fire department, which is about a kilometer away from my house. There have been a few times where I missed a call out and did not know that there was something going on until I saw the fire trucks rushing by my house.

I really wanted to have some way of scanning full time the four call out frequencies that the fire department uses in my area but still keep tabs on the other frequencies that I am scanning. It didn't really make a lot of sense to buy another scanner just to monitor a handful of frequencies.

However, I did have a few spare SDR (Software Defined Radio) dongles sitting around from my Glider and Balloon tracking projects. Could I use these for a dedicated scanner for my fire department?

Sunday, September 13, 2020

A Wee Life-hack - Making a Simple USB Battery Adapter

Who needs batteries?

Towards the end of summer, I always make a pilgrimage north to do a little bit of fishing. 

Since the place that I usually go has a decidedly poor coverage area for cell and internet signals, I find that those few days of fishing to be my time to fully disconnect from the world and recharge my body and spirit. 

The type of fish that I go for typically is the type that will go only for the freshest of bait - for some reason they are just not easily fooled by artificial lures. 

They especially seem to have a fondness for minnows, which, for those that aren't familiar with all things fishy, are a small fish that about an inch or two long - just the right size for the big ones that I am angling for to swallow in one bite. 

The issue is that the minnows up north know this too, and tend to be very timid about being captured for use as live bait. 

The minnows in the creek near my house however, don't seem to have this fear and are easily persuaded to enter my minnow trap with a few bits of bread. 

The challenge is how to transport my minnows so that they stay alive and well for the 2 hour trip to my fishing spot.  The key to transporting minnows is to make sure that they have plenty of oxygen in the container that I am hauling them in. 

Sunday, September 6, 2020

A Monthly Surprise in the Mail - Checking out a Kiwi Crate

A box of goodies

A few months back I developed a bit of a guilty pleasure in watching unboxing videos that seem to be everywhere on YouTube. 

The concept is that you get a box from an online store and you film yourself opening the box, removing and critiquing the items in the box. I actually tried my hand at doing one myself with my new table saw.  

Admittedly a very odd concept - but a very popular one, and strangely compelling to watch.  I suppose with fewer people going to physical stores, this has replaced "window shopping". 

I am especially drawn to watching unboxing videos which definitely are a spoof on the whole genre

In particular, the videos that I watched seemed to delve into something called "Crate Boxes". Crate boxes are usually part of a monthly subscription where you get a box full of goodies delivered to your front door each month. These crates are usually geared to a particular interest (movies, video games, etc.) and the contents of the crates usually follow a monthly theme. 

Most subscriptions are actually pretty reasonable for what you get - usually around 20 or 30 dollars a month. 

There are quite a few of these subscription crates out there. For example, my spouse subscribes to a crate that sends her goodies for her card making hobby. 

The other day, I saw a post in my Facebook feed about a crate subscription service called KiwiCo that offered something called a Kiwi Crate. 

KiwiCo focuses its crates towards providing STEM, STEAM, and Science kits, mainly for kids. 

While I haven't been a kid for a long long time, I noticed that they had various levels of crate subscriptions based on various age and interest levels. 

I was actually surprised to see that they did offer crates for "older" kids in the 14 to 104 age range with 2 crates - a Eureka Crate that was geared towards Science and Engineering projects and a Maker Crate that was aimed towards Arts and Design projects. 

Of course, I was more drawn towards the Eureka crate so I checked it out a little more. 

I was actually pretty impressed with what you got in a crate. A crate usually contains a very useful item, such as an electric pencil sharpener, or an articulated desk lamp the comes in a kit form. Again the items have a heavy STEM slant as they use the assembly of the item as part of a teaching exercise. 

I was actually pretty intrigued, so I subscribed for the Eureka crate, with my first crate arriving at my door a couple of weeks later.