XBee Basics - Lesson 2 - Simple Chat Between Two XBess in AT Mode

Key Takeaways

Hello and welcome to lesson two video tutorial on XB basics. In this lesson, I'm going to show you how to create a simple chat using two XBs in AT mode. All right, let's keep this as simple as we possibly can. Here's a diagram of what we're going to be doing. We have XB number one is going to be the coordinator and it's going to be in AT mode. XB number two is going to be the router in AT mode. They're both going to be connected to the laptop. using a serial ca cable. What we're going to try to do is get into the terminal of router of the router XP and then send data messages over wirelessly to the coordinator XP and see if we can receive that data. Okay, so let's hook everything up. First, we'll deal with the coordinator. We're going to hook the FTDI cable up to the coordinator, and we'll connect this into the laptop. Come on. Okay. So, that one is ready to go. That's done. Next, we'll connect the router. So, first, um, we'll connect this into the breadboard like so. And then we'll connect this into it using the right pins. like so. And I demonstrate all of these different serial capabilities in the previous lesson. So, if you're unsure what I'm doing, just go back a lesson and watch that one. Okay. So, now I'm connecting this one in here. And our connectivity is complete. So now that I have both XBs connected, let's open up the XCTU software. Here you're going to see two comp ports hooked up. Comport 11 I know as a router and compport 12 is the coordinator. So let's let's configure comp port 11 first. So we're going to go into the motor configuration and then read. I'm going to actually restore this to factory default just so that you can follow along with me from scratch. Okay. So, from here we see that the router well this this Ziggb this XB is a router and in AT mode. So, that's great. We'll set the pan ID to 7779. Just something random. Let's keep them all the same. Um, I'm choosing JV as enabled so that I can more aggressively try to join the network. The destination address I'm going to leave as zero, which means that it's going to try to communicate to the coordinator only. So, I'm going to write those settings. And that's it for the router. I'm now going to open up a second XCTU instance. And I'm going to move this to the side. And this time, I'm going to go into 12 COM 12 and check out the modem configuration for this. Again, I'm going to restore and then read. That way, we're setting at factory defaults again. Okay, this one I can see already needs to be changed. The coordinator, yes, but at needs to be what we're dealing with. So, let's write this as a at. The reason why they're both at is because we're going to be using transparent communication through the XBs and not to them. Okay. So now it's the coordinator and I'm going to read after it finished uploading. That's good. Okay. So now the pen ID, we need to set this to the same which is 7779. And basically that's all we need to do here. So I'm going to write that and that's going to save the settings to the XP itself. So here it says write as complete. So now what I'm going to do is go into terminal tab on both of these and on the router side I'm going to type a message and you can see it showing up on the coordinator side. So basically anything that I chat on the left side shows up on the right side. Um the router is wirelessly sending data to the coordinator. I just want to talk about these lights real quick. So I could tell that this is the coordinator one because the green light here is blinking about once per second. Uh the router one is blinking about two times per second and endpoint will also blink two times per second. So this little green light helps you understand which one is doing which. If the light is solid, it either means that it's booting up or it's looking for a network. Whenever we send data across the network, you can see the red light turns on. Here I'm hitting enter key. And you can see the red light here is turning on and the red light here is turning on. So anytime that I send traffic across, the two red lights turn on. So, I think that was a little bit too easy. Let's complicate this chat program a little bit more and make use of Arduinos. So, I love diagrams. And once again, I'm drawing a diagram to show you exactly what we're going to be doing in the next step. So, XB1 is still going to be the coordinator and it's still going to be in AT mode. And XB2 is still going to be a router and an AT mode. And what we're going to do is connect an Arduino up to each one. this Arduino, the TX is connected to the RX port on XB and the Arduino RX port is connected to the XBTX port. And the same thing here, Arduino TX is connected to XBrx and Arduino RX is connected to XBTX. Then the both Arduinos are connected to the laptop. And what we're going to do is tell the lab tell the Arduino program to send a message to XB which is then going to wirelessly communicate that to the other XB which is then going to be read into Arduino. And then we're going to monitor that Arduino session on the uh terminal on the laptop. There's actually no changes that we need to do to the XBs themsel. All we're really going to do is add the Arduinos into the network. So let's get to work on building this. So this I've configured as the coordinator. So I'll use this Arduino as the coordinator's Arduino. So first I'll plug it into the breadboard. And now I need four pins connected here. Um first we'll do TX on the XB to RX. And then we'll do RX to TX. And now we're going to need 5 vols plugged into it which is there and ground which is that one. So now the coordinator Arduino XB pair is complete. So now let's do the other one. Uh we'll put this guy right here at the end. Can you hear that? That's my neighbor shooting fireworks off in his front yard. So now the router XB I plugged into the breadboard and we'll use this um Arduino here and we're going to do the exact same thing. Um TX here goes to RX here. It's hard to see at it. And then RX goes to TX. And now we'll do plus 5 volts here goes to 5 volts here. And ground here goes to ground there. Okay. So, now let's get let's get these guys connected. We'll use this guy here. All right. So, they're all connected the way we want. So, now let's look at the Arduino software. So, I've loaded up the Arduino software. Um, on the left side is the router. On the right side is the coordinator. So, let's start with the router. First we have to establish the serial port and then our main loop is just print line hello world wait for 5 seconds and then do it again and again and again and again. So basically just sending out the serial on the coordinator side. Same thing. Start the serial connection in the loop. If serial is available if it's more than zero, then we're going to do serial write whatever is in the serial buffer. So serial read and then write whatever is in serial read out to the buffer. So, whenever you go to upload a uh a program to the Arduino and the RX and TX ports are connected to the Arduino, you need to disconnect those to upload it. Otherwise, you get an AVR dude error. So, I've already uploaded both of these files to the Arduino. And I'm just going to head the serial monitor on the receiving side. So, this is the one that we're receiving it to. And although it doesn't look exciting, it certainly is working. The router is sending the message hello world to its XB. The XB is then transmitting that wirelessly to the other XB, the coordinator, which is then sending that data to the Arduino. And then I am reading the comp port for the Arduino on the on the coordinator side. This is actually the coordinator on this side. Now you can see it blinking once per second. This is blinking twice per second. The red light goes on. It stays on for 4 seconds. Now it went off for a second because every 5 seconds we're actually sending data from this Arduino to this XB over to this XB to this Arduino. And then the output of that is right here on the screen. Hello world. So that is a simple chat program that you now know how to make between two XBs using a combination between combination of either serial cables or an Arduino. And as you can see, it was really simple to do this. But that's just scratching the surface of what XB is capable of doing. In the next few lessons, we're going to be learning how to get data from individual pins off of the XB and communicate to the XB and um gather data from the XB itself. So, basically on the remote side, we won't be needing this Arduino anymore. Hopefully you tune in to those and I'll see you next