4 gigahertz express lrs uh parts from happy model, so they have a micro module and three different types of receivers for the 2.4 gigahertz system, so the express lrs firmware obviously is open source. I did a video on the 900 megahertz system previously i’ll link that down in the video description. You guys can check that out. Im grunde, they have um modified the hardware so that it will work for 2.4 gigahertz antennas, but i think the firmware is largely based on the same um software. So you can you know you can correct me if i’m wrong on that, but uh you know, tun. Let me know down in the comments as far as my understanding is: it’s uh the same base software and then they’ve, Äh, branched it off into the 2.4 gigahertz and the 900 megahertz systems. And i think the hardware is a little bit different. But the chips and stuff um, the actual receiver parts are really tiny on the on these new 2.4 2.4 gigahertz parts. Also, first let me just show you what comes with the um, the micro module there’s, going to be a nano module at some point in the future. I don’t know when that’s going to come out so get the module here. You get this 3d printed case for the module, so that obviously it’s a jr module bay case and then you get a uh looks like an ipex, connector or microfl to looks like sma, and then this is the antenna for the transmitter, obviously shorter for 2.
4 gigahertz And it’s an sma antenna and you get a screws and some sticky pad to hold the board inside the module there or inside the little case, but this is what the actual board looks like. This is where you connect the antenna, get some jumpers there. You got a micro, usb port there that doesn’t look like that’s going to be accessible, it’s going to go in like this and then it’s going to get covered up with those screws. You put those four screws in there and then obviously this will go into your radio, so whatever firmware updates occur. Äh. How to you have to take this cover off, to be able to access that port to be able to make those changes, but um looks like it’s fairly straightforward. You just connect up the antenna like that, and then this will go Music in here. You know i just put nut on the other side to hold it in place, close it up and that’ll get your module going, but this is what it looks like and nothing on the back side now the receiver or the the receivers are super tiny. So these are there’s three types there’s this one called pprx over here that’s, like the the reference design that was actually originally designed by the express lrs developers, and then they have the ep1 rx and the ep2 rx. And then these are uh designs from happy model and my understanding is the main difference is and how the firmware is updated so and the reference design, the pprx, the the firmware on here, will get updated via video flight pass through.
Also, im Grunde, through your flight controller and then on the newer or, Ich vermute, the other alternative receivers from happy model, these are the happy metal designs, the ep1 and ep2 there’s, actually a different chip, a different mcu that actually has a wi fi antenna on there, so That will basically allow you to update the firmware on the receivers via wi fi. I don’t have any details on how to do that, specifically so i’m, going to have a future video later to explain that, because i didn’t get a clear understanding of how that is done via wi fi. Offensichtlich, you have to connect to it, probably through a smartphone app or something that i imagine i wasn’t too clear, yet um again, ich bin, going to link all of the the stuff that i linked before in the other video the 900 megahertz video. In terms of the the github and the wiki pages, and all that they’re, probably going to have more more up to date, information down the road – this is more or less a preview. I haven’t actually flown this or tested this yet um, but it’s going to take some time to get all this tested. But i just wanted to make sure you guys were aware of this and that they are on pre order now and i think uh will be available in probably about a week after this video is out, but mainly i wanted to get the size of these things.
Just to scale this out there, because it’s just amazing how tiny these are so here is a standard crossfire nano receiver from tbs, pretty you know pretty statuses with the uh. You know regular uh standard antenna, not the immortal antenna but here’s the pp antenna that’s, a reference design from express lrs and it’s got this ceramic antenna on here, so there’s new antenna, Connector, obviously there’s going to be some debate about range or whatever i you know, We’Ll see i’ve done any range testing yet but yeah. This is incredibly tiny. You know you just can’t really depict how tiny these are. These i’m afraid i’m going to lose them somewhere because they’re so small. They literally look like about half the size of a crossbar nano receiver and let’s see how much this weighs yeah so coming in at 0.42 Gramm. Now this uh this one here is the ep2 design from happy model similar in size, but the ceramic antenna. So with no external antenna – and there is a small little wi fi antenna right there in the corner, you can barely see yeah it’s really hard to show. That is the connect as the antenna to connect to the chip to do the firmware updates. But i think it’s the same size as the pp2, so ist hier, the the pp receiver on the left – and this is the ep 2 on the right let’s see here. You know they’re about the same size.
So ist dies, the in terms of the transmitting or receiving chip, is the same it’s. Just the mcu is different uh for the wi fi functionality. Let’S see this so they’re, both the same size and then uh let’s, just see if it’s, probably the same weight 0.44, and then this one here and we’ll get these mixed up. This one here is the ep1 design with the again there’s the into the wi fi antenna, and this one has the micro fl connector, the ipex connector. I think it’s ipx4 and then you get uh two types of antennas. Here they have a 40 millimeter antenna and a 90 millimeter tan that’s included in the package. You can buy these separately if you break them or lose them. Those are also available with. Obviously this is gon na be a little bit lighter because it doesn’t have the ceramic antenna on there. But of course you have you, don’t account for the weight of the antennas themselves. That’Ll actually increase the weight so 0.’, no antenna and here’s the 40 millimeter antenna that will make the weight 0.81 Und die 90 Millimeter 10. It goes up to 0.96. So offensichtlich, if you’re going to go for the lowest weight, you want one of the ones with the ceramic antenna and obviously it’s not going to take up a lot of space other than the fact that the antenna, the ceramic can just stick up a bit. So you do have to account for that, but you can definitely put this into some really small whoops or something like that.
Weighs almost nothing and you’re going to get like massive amounts of range on something that’s not going to have the flight time to fly. That far, basically for anything that you’re going to be putting this into that’s, really small and light isn’t going to have enough battery to fly to the limit of this receiver. I'M. Pretty sure about that, and you can put these into something bigger and possibly see what the amount the maximum range is. But why would you want to put something with a minimalistic antenna like this into something that’s much much bigger when you can just put it? You know just go with the bigger antenna. I mean the half a gram weight isn’t going to cost you anything on a seven inch, so yeah it’s kind of kind of pointless to put putting something like this on a seven inch to see what the maximum range is uh. This is going to go into something more like a three inch or something smaller and the flight time of those is going to be short, so a point that you’re not going to be able to run out of range of whatever. This is pretty sure about that. Aber ja, if you disagree with me, let me know down in the comments. If you have different findings uh, my understanding is uh. The range on this is pretty similar to the 900 megahertz parts. Offensichtlich, it’s going to be somewhat different with the ceramic antennas, but it’s just i just don’t, see it running out based on just battery life or something that is tiny and what this might go into anyway, more videos on this later.