In this video of the Meshtastic for Makers course, we'll be exploring channels and frequency slots, two very important settings that you need to know before you start sending your valuable data. We're going to be continuing with our Pico, which we set up last video, link in the description if you need that. First of all, let's look at frequency slots. org. Under config and then Lora, you're going to set the option here to change your frequency slot. By default, it will be set to zero, which sets your device to the default frequency slot of your region. And if you change this number, you will change the frequency your device is operating on. Just so we can see what's going on, I'm using this tool on the mesh test site. And as you can see, frequency slot one in the Australia region is going to be 915.125 megahertz. But if I were to change over to frequency slot two, it's going to be 915.375 megahertz. While this 0.25 megahertz difference might not seem like much of a change, if one device is on frequency slot one and another is on frequency slot two, that slight change in frequency is enough that they won't be able to talk to each other. In fact, they probably won't even know that the other one exists. More importantly, these two devices won't be creating that meshing network together. If a device on slot one sends a message, the device on slot two is not going to repeat it. They are both sort of isolated from each other on different frequencies. And that is what frequency slots do. It allows you to isolate yourself from other devices on the mesh testing network.

But why would you want to isolate yourself? For mesh testing networks can actually be overloaded if there are too many devices in one area. If there are lots of people in your area using mesh testing and sending messages all at once, you can actually have too much network traffic and cause kind of a metaphorical traffic jam. This will probably only be an issue in larger cities. And when we say a lot of devices, we mean like a few hundred or so, but it really does depend. So there is an element of responsibility here. If you're going to be sending sensor data a few times a minute and you already live in a very busy area with lots of other mesh testing devices, chances are you may overload the network and cause a traffic jam of all your messages. In that instance, you should probably think about moving your device to acquire to frequency slot with less or no devices on it. But also be smart about it. If you do live in a busy area and you're only sending maybe a message every hour or less from one device to another, you're probably not going to be putting too much of a load on this system. And you might be able to get away with staying on the default slot. Be responsible, use your head and maybe even ask the Meshtastic community in your local area. What is the good thing to do here? But for the majority of viewers who live in an area with barely any devices, stay on that default frequency slot. There is already a lack of devices around you and if you change frequency slot, you're not repeating messages and helping to build your local network. There's also one more thing here. You should probably manually set your frequency slot. If you set your device to slot 0, it's just going to automatically set your device to whichever slot is the default in your region. In Australia, if I set it to slot 0, it's actually going to be set to slot 20, which is the default number. So if I set one device to slot 20 and another device to slot 0, they're actually going to be on the same frequency. Zero just sets it automatically and when I put in 20, I'm setting it manually. We'll talk about it in a little bit, but if you leave it on slot 0, a mesh test, it might actually change the slot that you're working on. And that might isolate you from everyone else without you even knowing. So we're going to go ahead, set it to 20 and save it. But remember, the default frequency slot is probably going to be different depending on your region. And in the written course below, we'll have a list of what frequency slot is the default in what region. So go check it out and set that at your slot.

All right, now let's talk about channels. So right now, our Pico is able to use the Meshtastic network very happily. But by default, it's going to be using the public long-fast channel that everyone in range is a part of. This is fine for a friendly conversation or meeting people over the network, but not for sending sensor data over. So we're going to create our own private channel. This is not only going to protect our data and keep it a little more private if we want, but it's also going to prevent us from annoying everyone around us. Because if we constantly sending sensor data every minute on the minute or some sort of automated message in that public chat, this is probably going to annoy everyone in the area very quickly. Now, changing channels is different to changing frequency slots. Changing channel keeps you on the same frequency. And it's more like creating your own private group chat for your devices. Let's say I set up two devices in a private channel and a third in the public default channel. All of these devices will see each other and repeat each other's messages. If I send a message in my private channel, only the devices in that private channel will be able to read those messages. The third device will repeat the message and build the mesh network, but it won't know what the message means because it's not a part of the channel. It just repeats word-for-word the encrypted message it hears without understanding it. So if you set up your devices in a private channel, you will still be able to see all the other devices in your area. They will still repeat your messages and vice versa, and you'll still contribute to building your local coverage and everything like that. But you'll be able to send messages that only you and other devices that have the details to this channel can read.

So to set a channel, we're just going to head on to channel. And here you'll see that eight different channels that your device can be a part of. There is the primary channel and then seven secondary channels. Now, unfortunately for us, much of what we would do in this course will only allow us to use the primary channel. This is because the method that we're using to automatically send data is only going to be able to send it through whatever we have set as the primary channel. This isn't really a thing to worry about though. We just need to know that our data will only be sent through whatever channel we have set as the primary one here. So to create a channel, we'll just go ahead and create a name for this channel. We're just going to set core demos, our channel name, whatever you want as long as it's not too long. You also have the option here to create a password. You can leave it as empty, which means it actually doesn't have a password. Or you can send an 8-bit 226-bit password. Just be aware that if we generate a password here, yep, and we take a look at it, it's going to be a certain amount of characters followed by two equal signs. Every password is always going to be followed by two equal signs. Just important thing to know. We're just going to leave it on empty because we're not too fast about our security here. Once you've created a channel, go down and hit submit down below like that. And if we head on over to messages, you can now see that we're part of the core demo channel. Whatever channel name that you've just set. If you want to add another device to this channel, just do the exact same process again with the same channel name and password if you're using one. Also remember that these are case sensitive. So core demo and core demo are two different channels. Now, I've gone ahead and set up two more devices here. The test device too is actually on the public long fast channel, that default channel. And test device three is set up without private channels. So if I go ahead and send a message from test device two, we get nothing because it's not on the channel. But if I send one from the test device three, it says it like so. That public default channel was assigned to the primary channel. So by changing it with kind of removed it. And if you ever want to return to that channel, you can do so by entering in these channel details here.

Okay, one more little thing. And this is a very important catch. Messedastic does something a little bit weird if you change the channel of your device. It may also change the frequency slot as well. When you change your channel, Meshtastic might automatically change your frequency slot to help fight network traffic congestion and all that sort of stuff. The good news is if you set up two devices in the same channel, it is smart enough to set them on the same frequency slot so that they can actually talk together. But because they're on their own frequency slot, they're going to be isolated from everyone else's devices. This is why we said to manually set your default frequency slot for your region. If you manually set your slot, it stays there. If I set it to 20, it's always going to be on 20. Messedastic will only change it if I set it to zero. When I changed the channel of test device one here and test device three, it actually isolated it and I couldn't see test device two here because it was still on the public slot. I had to go into my config, Laura, and then change them to both frequency slot 20 so that they still remain part of this machine network.

All right, that was a lot of very important information. So let's quickly recap. One, if you live in a really busy area where sending messages might cause a traffic jam, change your frequency slot to isolate your devices. Two, you can create your own channel to privately send messages between your devices, but it won't isolate you from other people's devices. And three, if you do change channel mesh testing might try and change your frequency slot. So ensure that you manually set it to the one that you want to use. Do not leave it at zero unless you just want mesh testing to decide for you. And as always, until next time, happy making.