UPDATE: I learned something too because of YOUR feedback. The BN-180 here bit.ly/3f3PHW4 does have a battery (so a faster fix potentially) and does also come recommended for those looking for a light weight GPS from other pilots. For me, as seen, I'll stick the biggest one possible into a smaller model due to the dynamics I have where I fly frequently (I have issues getting a lock before launch). Matt
Hey Matt! The battery isn't to remember the sats for the same location, it's for any location you can still 'see' the same sat. Having the battery is the most useful for when you land and swap batteries- without one it would take the full 1-5 mins to get a fix. The fun detailed answer: (I've worked extensively on low-level GPS software) Your GPS unit needs to know where the sats in space are. It takes time to receive all of what's called ephemeris data which are the orbital parameters for a satellite and is only valid for a few hours (hence being ephemeral). Once it's received ephemeris data for 4+ sats it can calculate your 3d position. It also, slowly, receives what's called almanac data that's valid for many days but gives a less-accurate sat position. Having the battery lets your GPS receiver store ephemeris, almanac, and often keep its clock running- all so power-cycles can get near-instant fixes. The reason your smartphones can get instant fixes anytime anywhere? It asks the internet for that ephemeris data and never waits to load it from the sats themselves!
how does a GPS module like in this video get it's time synchronized? Because if I comprehended right, the satellites send a signal with their position(coordinates/location above earth) and exact time of transmission, and the receiver receives this signal and compares the time of transmission to the current time to calculate how far the satellite is(the more time difference the more far the satellite is, and vice versa), but if the receiver doesn't have synchronized time how can it know how long it took for the signal from the satellite to be received?! could it be that the manufacturer of a GPS unit synchronizes the time of the unit at the factory and the small battery mentioned at 1:12 is like a CMOS battery on a computer to always remember the time? But I don't think that is the answer because the battery can become empty in storage.
Good question@@flat-earther, time is vitally important for this system to work. Time is a variable to solve for, just like position, and the reason four satellites are needed for a 3d fix. Initially the GPS receiver can guess it’s rough time from the timestamp in Ephemeris packets. Then, from the delay it measures, it can calculate the distance to each satellite. Because the receiver’s time is a rough estimate these distances are called pseudo-ranges and the actual ranges are all off by a single delay to all satellites.. that’s the delay the receiver can solve-for and get an extremely accurate time.
Some notes: iNav supports a magnetometer for multirotors, Betaflight detects it but Betaflight's rescue mode does not require a magnetometer (in fact it seems to work better without one). There is a variant of the BN-220 called BN-220T which seems to get the initial position fix slightly faster. The provided cables are of the cheap plasticky kind so if you happen to have silicon wires with a 4-pin JST-SH connector (or a crimping tool) you are much better off using that.
Hi Matt, You totally killed the pronunciation of the brand "Beitian". You made it sounds like its from another planet like martian! It should be pronounced as "Bei-T-an", "Bei" as in Bei-jing, "T" as in the letter T, "an" as in the english word "an". If properly translated it means Northern Sky. Cheers mate!
the 880 has an active antenna from where as the 880q is just a passive antenna. I however think the extra durability outweighs any loss in sensitivity i get 18 sats solid most of the time in inav. Be careful some FC boards 5v supply can fry the compass chips i would power these gps units from a known 3.3v supply on the board. Plus of this is you can get your gps a fix via usb power.
Hi Matt, don't forget the BN220's BIG antenna brother the BN280.. And don't place it under too much foam, despite being an insulator, it (and plastic) has a tuning effect that can degrade the performance, with some EPO and EPP foam it's quite a bit. It doesn't block the signal, it just alters the resonant frequency of the antenna when placed very close.. Cheers.
I use the BN220 for just about everything these days. It often detects up to 23 satellites, it's cheap, and light enough to use even on a high-altitude balloon where every gram counts. The BN180 is only half a gram lighter at 5.0g vs 5.5g and only a few mm smaller so I'm not seeing any major advantage over the 220. As far as I can tell performance of 180 and 220 is the same.
I have a BN880Q, and for some time now, it's taking 7 minutes to get 4 sats, and more than 11 minutes for 8 sats. It hardly surpasses 9 sats. A year ago it locked 21 sats easily and in less than a minute. Could that be the battery? Could it be a past crash? I'm clueless.
These key details saved my life: those boards with i2c pins (SDA and SCL) have a compass, RX from the GPS needs to go to TX on your FC and vice versa and quadrotors needing a compass to navigate. Also: i2c is just a network, so you can connect more than one device to the same i2c port, just make sure their addresses are different. :)
Thanks for this video! Poked around Aliexpress after watching and found the BN-250, which looks like a 3mm larger BN-220 but with the 880's antenna. Going to give that one a shot as I definitely don't need the compass on any 880 model. Looking forward to your performance tests.
Weight is always relevant in Fpv reviews... #Breakoutthescale! Thought the 880q has a compass which does not seem to function well with INAV... Love your enthusiasm and the way you communicate the joy of model aviation.
Not boring at all. Pretty helpful. It's tempting to get the 880Q when BG has them for 11 USD, but most of the reviews/Q&A say the compass is fake and doesn't work. After hearing that bigger is better with antennas, the 880Q might still be a viable option at that price.
Hey Ted, I don't ever use the compass, it's the size of the antenna that really does make a difference. Did you see the size of the one rammed in the Dart 250g lol!
Hi Ted, I believe it was the earlier models of the BN880Q that had issues with the compass, I have a recent one (withinn the last 5 months) and have not had any problem with the compass, saying all that you dont need it for aircraft so just disable it in Inav unless you are using it on a multirotor 😎
The 880Q uses the newer QMC5883L instead of a HMC5883L compass. The chip pinout for these two compasses is compatible but the data registers are different so you can't just use the same communication code. Most likely the people saying the Q was fake were using firmware that simply did not support it.
Measure the voltage on the 3.3V button battery. I got 0.8V on a gps less than 6 months old. The uBlox data sheet spec the backup current at 15uA. That would give you a month on a 10mAh battery. I used a razor blade and broke the tab spot welds by gently tapping razor blade to cut through. 3d printed a cr2032 battery case to solder up to gps. Should give about 6 months based on 15uA. I guess most people just wait for cold start every time the put a new flight pack on. Ugh!
Hi Matt, would you be able to do a comparison in regards to signal strength? For these devices there is a PC software called u-center that is capable to get raw data from these GPS units and compare signal quality and strength.
I strongly do not recommend the BN-880 GPS module. Motos highly influence its magnetometer. Recently, I have lost my drone, and I have switched the BN-220 to BN-880. Before the change, the GPS Rescue was working properly. After the change, my drone does not go back to me when GPS Rescue mode is activated. Apparently, the Drone gets crazy, and it does not manage to fly direct to me. I am using BN-220T, this version has a hot start. Salute from Brazil. Way to go!
From Hubby Paul (newbie) - Thanks Matt, very well explained. I have started installing ZOHD Kopilot Lite (fixed wing ) and they all come with the BN-220. It can take forever to lock in GPS. I would like to try out the BN-880Q but how will I connect it to the ZOHD controller as the wire is different?
Hi, I am in the same situation as yours. I am also have units of BN-880Q, but aren't able to find any information on how to DIY the wires to have it connecting to Kopilot Lite. Wish you can share if happened that you had this information by now. Thanks in advanced.
Hi, great video! May I ask a few questions? I have the Kopilot Lite the bundle with my ZHOD 250 wing; recently I ordered the BN-880Q GPS module. May I know, does the BN-880Q can work with the Kopilot Lite? Do you have the pins configuration of how to connect the BN-880Q with the Kopilot Lite ? Also, I am not able to find pins assignment of the BN-880Q, is BN-880Q and BN-880 same pins assignment? Btw, I do understand Kopilot Lite will not support compass, I will not connect the compass wires. Sorry for asking so many questions.... appreciate your helps Thanks in advanced.
I'm about to made a motorbike telemetry app, and i want to know if the BN880 is precise enough for road navigation, and if the compass + an accelerometer could be a nice combo for getting precise telemetry. Thanks and nice video!
1:15... I have a BN-180 in front of me and it DOES have a battery. I would however still like to know the difference between the BN-180 and the BN-220.
@@goku445 Takes me right to the GPS-Max Speed Module page. Google J.BAUER Electronics GPS-MS or see the Y/T review here... ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-mABL0a5B73U.html links in the description.
What a useful video it is! Although I use BN-880 for airplane, I also have wanted to use BN-220 in terms of price and size. Next time, I will try BN-220. But GPS which doesn't has compass may not be useful enough for rover and boat, may it?? Because it is possible to stop it.
Hey Matt! Sorry for the off-topic question, but your shot of the Dart 250G prompted a question. I noticed that you're using a standoff between the motor and plane. How did you attach that? Did you use a screw that went all the way from the plane body, through the standoff, into the motor?
which way is the module supposed to face when mounted (or what way is "forward" on the 880?) and does the antenna side always have to face upward toward to sky?
I've a Matek 765-wing with Inav and GPS BN-880, I need some spare cable to solder Dupont to the GPS. What kind of connector is it ? (6 wires) thanks for tip answer if you can.
Would it help to have a shield (metal foil tape, for example), under the gps mod. to shield it from an esc, ( or other radiation ) or would it cause a "reflection" with the gps antenna. Also, can i use the 880Q with the Zhod Kopilot ?
Interesting video, thanks! Now all I need to do is work out why my BN-220 thinks my altitude keeps changing by +/- 25 meters. Even with 12 sat's it's not reliable (thank fu*k for barometers!). And no, I don't live on or fly from a boat. ☺
hahahaha is not boring i gess that some times you need to do your homework to be able to have a nice flight , i have lost 2 models before i understood that if you want to have a nice flight you need to make sure that each of the componets from your model no matter if is a fixed wings or just a quadcopter is working as is suposed to due to a simple mistake could get your model flying where you will never see it again or hurt sombody.
Has anyone managed to "talk" to these using arduino? Just to change settings. I have looked on the web, but nothing so far. I want to set the "pedestrian mode" and baud rate.
Hi Matt. I'm wondering about the compass in a fixed wing. I plan to use a Matek F405 in a model. I have no experience of inav or flight controllers. In the case of a return to home function how does the FC compensate for drift due to wind? Does it lay off for drift or just keep pointing to home so flying an arc rather than a straight line. Would a compass be useful for setting a particular heading in order to achieve the desired track? I live in Tasmania which is in the Roaring Forties so it is windy a lot of the time. Keep up the good work.
