BRB900 vs Eggfinder is there a difference other than build time and price?

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OH-FER

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I have been narrowly sneaking by with my RF beacon and rocket hunter system. But now I see that there are GPS modules that I can afford and some that are cheaper than the radio beacons. The two that seems best for me are the BRB900 with there standalone tracker and the eggfinder with the LCD system. I'm not a pro at soldering but I would like to get better so I'm not too worried about the Egg builds.

I would like to know if anyone has noticed a performance difference between the two. From what I can tell they seem to be relatively similar besides price and that one comes as a build kit.

Also does anyone have any recommendations on antennas to max the range out on these guys? Looking for Omnidirectional because some of my rockets are small an go out of sight so trying to keep a directional antenna on them might be tough. (feel free to argue that point).

But any help making this decision on what system to go with or other options would be helpful.
 
Eggfinder is on a fixed frequency (but you can chose which one when you order it). BRB uses a spread spectrum transmitter.
 
Eggfinder is on a fixed frequency (but you can chose which one when you order it). BRB uses a spread spectrum transmitter.

But The the new LCD receiver allows you to change the frequency to work with any of the egg-finder transmitter frequencies. right?
 
As mentioned above, the BRB900 uses spread spectrum transceivers, and each pair is assigned a unique ID so multiple systems can be active at once with out interfering with each other.

The GPS used is a u-blox MAX-7, approved for TRA records, and accurately tracks altitude during the flight after the microcontroller puts it into "air" mode.

On-board 1 M-bit flash memory tracks 2.5 hours of flight data at 1 hz for later download and viewing in google earth.

Operates off of a single cell LiPo battery.

Configurable transmit rates

Those are the differences that I can think of

Greg TRA 7960 L2
 
But The the new LCD receiver allows you to change the frequency to work with any of the egg-finder transmitter frequencies. right?

Yes but the transmitter isn't tunable with the EF. Only the receiver is tunable. Show up with a buried EF transmitter in a rocket and someone else is flying on "your" frequency, you'll have to wait until they get their transmitter turned off. Oh, you could tune your LCD receiver to monitor the other guy's flight if you want. Another negative is if someone's rocket gets stuck in an inaccessible place within field range (trees/power lines) with an EF on "your" frequency, you are SOL when it comes to flying your EF that day. Two EF trackers on the same frequency will interfere with each other.

The major difference like Greg points out is the BRB (he's the originator of it BTW) has onboard memory that makes it acceptable for
TRA record attempts. The EF does not do that and unless you have experience with data capture with your chosen ground station, you won't get a .kml file
compatible with Google Earth. (Well there is a way around this but it isn't easy) Since the BRB stores onboard, you'll get data all the way to the ground that's available for download when you recover.

If you simply want to find a sport rocket the EF/LCD is a no-frills economical choice. You can get mapping ability with an Android phone with Rocket GPS Locator if you add an HC-06 bluetooth board to your EF receiver. If your Android device doesn't have network access, you'll still have two spots and a datum line to follow to the last known position or you can simply input the lat/long into a handheld mapping GPS.

If you want the capabilty the BRB has to offer such as you don't have to build it, it works right out of the box, run it anywhere never having to worry about if anyone else is on "your" frequency, can get a very nice .kml file for perusal on Google Earth. (I've done that with the BLGPS ham version and it's a cool representation of your flight) and you can use it for record attempts, it would be worth your investment.

Another way I look at it is if I'm flying a nice rocket with a commercial load I believe stands a very good chance of a nominal flight, I use my BLGPS.
If I'm going to fly an unpainted test mule for an intial flight of an Ex load (after a successful ground test) that might get blown to high heaven, I'll fly
the EggFinder. It's easier to swallow the destruction of an EF than the pricier BLGPS. (I've lost a BLGPS in a crash and it hurts!) Also dropped an EF and terminally broke it on a hardwood floor. Less spectacular than a rocket crash and less expensive too.

I have both because 7 years ago APRS (Ham radio based GPS tracking) was the only economical game in town. The unlicensed options then were really pricey and with the Ham stuff at least one could use it for something else. The BRB 900 at $378.00 is a very economical option compared to the other "full featured"
TRA record acceptable units out there currently.

Realistically, look at your needs. Simply find a rocket and don't mind building a kit = EggFinder
Want out of the box carefree reliability with some nice options = BRB 900

Don't have the $$$$ and still want GPS tracking? You'll have to learn to solder with head magnification. (It's not that bad.)
Kurt
 
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Wow,Thanks for all the great info. I think for now Ill probably go with the economical route just to find rockets. But If and when I need more Ill probably go with a BRB. Thank again.
 
Is there any way, or any plans to make it possible, to get a map on a tablet/phone with the BRB900?
 
Is there any way, or any plans to make it possible, to get a map on a tablet/phone with the BRB900?

I suspect if the NMEA packets are read into a laptop they could be displayed using something like MapSphere as can be used with the EggFinder.

https://www.mapsphere.com/

I don't own a BRB900 or I'd try it and report. MapSphere is the simpliest program one could use and you could download some maps for portable use.
Only problem is it's not a real tracking program. By real I mean you have a GPS receiver on your base station and can monitor with a datum line to
your rocket. MS will show the rocket on a map but not related to your current base station position. It will show a breadcrumb line from the launchpad to the last known position of the rocket. Also with MapSphere one can't read lat/long from a screen directly. One has to save a logfile, minmize MapSphere and use a file reader to get the last lat/long to input manually into a handheld mapping GPS for the trip out the the rocket for recovery

Xastir can be kluged using a python script gps2aprs.pl to take the incoming GPS NMEA datastream from the rocket and display it as a trackable icon.
Xastir is a real PITA for the uninitiated. The only two realtime tracking solutions I've had experience with is with the Ham Radio protocol using a Beeline GPS 70cm (or 2m) transmitter with a Kenwood D72A, VX-8GR or FT1DR with a single serial cable plugged into a mapping Garmin 60Cs(X) or
78S(c). The Garmin will navigate in realtime to the rocket waypoint automatically but oh it is costly $$$$$. Can hit "navigate to" and can scroll to a datum line to direct you to the last known packet. If you get close and a new packet comes in, it'll take you there.

The other device is the EggFinder that simply transmits the NMEA sentences remotely. It's like having a USB GPS receiver plugged into a port on the laptop. With the EggFinder, one can use a Bluetooth module to bond to an Android device, phone or what have you and use Rocket GPS Locator:
https://play.google.com/store/apps/details?id=com.frankdev.rocketlocator&hl=en

It will download maps if one has a real time connection to the Internet. It doesn't seem to store many maps in the device without an internet connection.
It will STILL give one two dots, one blue for your position and one red flag for the rocket postion along with a datum line if there is no internet/map connection. Can still use it to track. Walk towards the rocket/red flag on the datum line and it will track you towards the rocket. If one carries the EF receiver along with their phone, if a new packet is received, it will be displayed.

I don't know the display mapping options of some of the other systems out there that don't require a Ham license. I am talking about the systems that cost more than a BRB900. I would think it would not take much work to develop a B/T option for the BRB900 but it is tied to a laptop with it's USB power/data cable. It might be convertible to portable power too if a B/T module were added. Could then bind to a laptop or an Android device to display the NMEA data on a map
by using GPS Rocket Locator.

If one's rocket lands several miles away, the last known position packet might be some distance away from the final landing area. By navigating to the last packet, one is likely to be in range to reacquire a new position to guide one to the final resting place. The reason for this is the reception range is much farther with the rocket up high. As it gets close to terra firma, if it's far enough away from the receiver the signal may be too weak for reception. Reception range on the ground is much less than in the air and if the rocket lands in a depression or ditch, it's even shorter.

Folks tied to a laptop tracking base station sometimes find if they read the last lat/long into a mapping handheld, triapse out to the
"presumed" landing site, they find no rocket. They have to go back, gather up the receiver/laptop and go back out to get within range to get a "new" packet. That is the advantage to carrying a portable receiving station.

Running around in the field with a laptop is a PITA. If the rocket isn't landing far away. no problem. Last received packet is likely close to where the rocket lies. Many laptop screens can't be read in sunlight very easily whereas handheld mapping GPS units are
readable. Some phone screens are readable in sunlight, some aren't.

There is no direct tracking program for Apple iPhones. Apple has an iron lock on licensing. There are GPS programs for the iPhone where one can manually input the lat/long and navigate to a spot. I don't have one so if one is aware of one besides Motion-X, correct me.

My suggestion is have a portable receiving station for GPS tracking that is handheld. One can use an Android phone for the EggFinder or just simply and manually input the lat/long into a handheld mapping GPS as can be done with a BRB900 or any unit that gives a remote lat/long indication. A used Garmin Legend would work for this (https://www.buya.com/Item/Details/G...4523417cc80e?gclid=CLb40ImUjMECFeZAMgodGywAQQ). One just has to be certain they have their lat/long units correct when going from their tracker/receiver into their handheld/mapping GPS. Practice this at home. Make sure the units jive between the devices or one won't find anything once they get out to the launchsite. Kurt
 
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First, I do not have an Eggtimer so only going off data sheets.

Eggtimer uses a SirfStar GPS chipset that is likely to give strange results on altitude during flight. It's filtering is designed for 2D movement not the high dynamics of 3D rocketry. It does well to find your rocket after landing but not so well at the actual flight track.

The BRB uses a uBlox chipset that is designed to be used in a variety of environments including flight. It does well on reporting altitude during flight.

Ken
 
First, I do not have an Eggtimer so only going off data sheets.

Eggtimer uses a SirfStar GPS chipset that is likely to give strange results on altitude during flight. It's filtering is designed for 2D movement not the high dynamics of 3D rocketry. It does well to find your rocket after landing but not so well at the actual flight track.

The BRB uses a uBlox chipset that is designed to be used in a variety of environments including flight. It does well on reporting altitude during flight.

Ken

Ahhhhh, it's "EggFinder". The EggTimer is a basic deployment computer.


I agree the altitude won't be as accurate but with the LCD receiver, can clue one in when to expect the main deployment. Since the unit doesn't have onboard memory, it can't be used for TRA record purposes. It was designed to be an economical GPS tracker to find one's rocket and the SirfStar IV chipset is adequate for that. Kurt
 
Absolutely agree it can find the rocket on the ground though somewhat skeptical about apogee. I flew a bunch of SirfStar 3 flights and found the altitude resembled an antigravity alien saucer more than than something obeying Newtons laws of motion. Apogee was an informed guess with signal processing offloaded to my imperfect brain.

The modest cost of upgrading this device to the vastly superior uBlox from SirfStar would be a good thing.

K
 
Absolutely agree it can find the rocket on the ground though somewhat skeptical about apogee. I flew a bunch of SirfStar 3 flights and found the altitude resembled an antigravity alien saucer more than than something obeying Newtons laws of motion. Apogee was an informed guess with signal processing offloaded to my imperfect brain.

The modest cost of upgrading this device to the vastly superior uBlox from SirfStar would be a good thing.

K

I think the current module is like $14.00 to $16.00 in bulk. I don't think a Ublox will run that cheap.:wink:

The price increase probably wouldn't warrant a change especially since there isn't onboard memory. Plus, once
the rocket is "easily" found, the flier can listen to the altitude beeps or download the apogee altitude. :D
Kurt
 
The primary purpose of the Eggfinder is to get your rocket back. Real-time 3D tracking is nice, but the reality is that all you need is the latitude and longitude of your landing position, or something close to it. Used with the LCD receiver, the Eggfinder makes that very easy. All you need to do is enter the lat/long into the navigation app on your iPhone; if you have an Android phone you can use Bluetooth and you don't even have to do that.

BTW, none of the ECIA distributors (Mouser, DigiKey, Avnet, Arrow, etc.) carry uBlox. They're a European company, so that's not terribly surprising; Bosch has changed distributors too over the past few years. The NEO-6 has been replaced with the NEO-7, which may account for its short supply.
 
The primary purpose of the Eggfinder is to get your rocket back. Real-time 3D tracking is nice, but the reality is that all you need is the latitude and longitude of your landing position, or something close to it. Used with the LCD receiver, the Eggfinder makes that very easy. All you need to do is enter the lat/long into the navigation app on your iPhone; if you have an Android phone you can use Bluetooth and you don't even have to do that.

BTW, none of the ECIA distributors (Mouser, DigiKey, Avnet, Arrow, etc.) carry uBlox. They're a European company, so that's not terribly surprising; Bosch has changed distributors too over the past few years. The NEO-6 has been replaced with the NEO-7, which may account for its short supply.


My question there is are the ublox units as economical as the Sirf IV that is currently used? John says they're as economical. I wonder if
that's true? The EF wasn't designed to chase records so the relevant thing is the accurate lat/long to track the rocket down. It certainly can do that based on the picture of a flier standing next to the red shockcord of a nominally recovered rocket, "buried" in a millet field.
Kurt
 
I always use the following to help me understand what we have here.

It's called an Eggfinder, not an Eggtracker.

It helps you find your rocket. If you want something more, there are other options on the market. This product fills a niche of a low cost gps locator which is what we wanted. Of course now that we have it, we start lamenting about the things it can't do rather than the thing that it does do (and does very well at a low cost).

When I'm at the point where I want to track my flights, I'll upgrade to a GPS tracker such as offered by Big Red Bee and Altus Metrum.

Color me one happy Eggfinder (and Eggtimer) customer.
 
The goal of the Eggfinder was to build an economical GPS rocket recovery device that was relatively simple to use, and didn't require the user to futz around with programming the GPS module. The uBlox units are more flexible, there is no doubt about that. They are also significantly more expensive than the Maestro Wireless unit, are not as readily available, and wouldn't do what I wanted to do right out of the box. The A2235H GPS module that's in the Eggfinder has its firmware in ROM, so it can't be messed up, but the corollary is that there are a limited number of "programming options" available for it. Out of the package it does what I needed it to do: stream NMEA serial data at 9600 baud. The only thing that I would really think about changing is to have it omit the $GPGSV records since I don't use them and they take up bandwidth, but it's more of an annoyance than an actual problem.

I think that BRB & Altus Metrum should be glad that the Eggfinder is doing well, because as Chuck inferred it's going to be a "gateway drug" into telemetry for many users. I've already had some people inquiring about the Eggfinder being a general-purpose telemetry platform; it ain't gonna happen, folks. There are plenty of other options, so I really wouldn't be bringing anything to the party. If you need more range, BRB & Altus Metrum may be a better choice; if you want a ton of telemetry options, Altus Metrum has you covered.
 
The goal of the Eggfinder was to build an economical GPS rocket recovery device that was relatively simple to use, and didn't require the user to futz around with programming the GPS module. The uBlox units are more flexible, there is no doubt about that. They are also significantly more expensive than the Maestro Wireless unit, are not as readily available, and wouldn't do what I wanted to do right out of the box. The A2235H GPS module that's in the Eggfinder has its firmware in ROM, so it can't be messed up, but the corollary is that there are a limited number of "programming options" available for it. Out of the package it does what I needed it to do: stream NMEA serial data at 9600 baud. The only thing that I would really think about changing is to have it omit the $GPGSV records since I don't use them and they take up bandwidth, but it's more of an annoyance than an actual problem.

I think that BRB & Altus Metrum should be glad that the Eggfinder is doing well, because as Chuck inferred it's going to be a "gateway drug" into telemetry for many users. I've already had some people inquiring about the Eggfinder being a general-purpose telemetry platform; it ain't gonna happen, folks. There are plenty of other options, so I really wouldn't be bringing anything to the party. If you need more range, BRB & Altus Metrum may be a better choice; if you want a ton of telemetry options, Altus Metrum has you covered.

Whaddya mean Cris? Don't use $GPGSV? :rant::wink: One can download the Android Program "Bluetooth GPS" and certainly monitor that data:

https://play.google.com/store/apps/details?id=googoo.android.btgps&hl=en

$GPGSV
GPS Satellites in view

eg. $GPGSV,3,1,11,03,03,111,00,04,15,270,00,06,01,010,00,13,06,292,00*74
$GPGSV,3,2,11,14,25,170,00,16,57,208,39,18,67,296,40,19,40,246,00*74
$GPGSV,3,3,11,22,42,067,42,24,14,311,43,27,05,244,00,,,,*4D

$GPGSV,1,1,13,02,02,213,,03,-3,000,,11,00,121,,14,13,172,05*67

1 = Total number of messages of this type in this cycle
2 = Message number
3 = Total number of SVs in view
4 = SV PRN number
5 = Elevation in degrees, 90 maximum
6 = Azimuth, degrees from true north, 000 to 359
7 = SNR, 00-99 dB (null when not tracking)
8-11 = Information about second SV, same as field 4-7
12-15= Information about third SV, same as field 4-7
16-19= Information about fourth SV, same as field 4-7

All's I do is pair the HC-06 from the EF receiver (LCD or the blind receiver), fire up the B/T GPS program and click on HC-06. What that does is subvert the internal GPS of my Nexus 7 Flo (no cell phone inside) and it will allow me or anyone to see exactly what is coming out of the EggFinder and what satellites it's using and the relative accuracy. This messaging stuff I don't know anything about but can get an idea what's going on "inside" the EF remotely while on the pad.

When done, I just disconnect the HC-06 from the program, shut it down and fire up GPS rocket locator to get my two tracking points and a datum line to follow. One could use the "Bluetooth GPS" program by itself as it gives a dashboard with lat/long and one could transfer the info to a handheld mapping GPS. That would entail the use of three devices though. I have a small box I painted the inside flat black to suppress the glare of the sun and I can hold it with one hand containing the N7 and an EF receiver. That way I have a one handed tracking station that is readable under most conditions. Substitute a Ham radio H/T and a Mobilnkd TNC for the EggFinder receiver and one has an APRS tracker for the Ham band with APRSDroid. Kurt :gavel:
 
The $GPGSV records can give you a nice picture of where the satellites are and their relative signal strength, but I don't use it in the LCD receiver. The only thing that I really use is the number of satellites in view and the HDOP, they're conveniently in the $GPGGA record.

Of course, the $GPGSV records are parsed by other software such as MapSphere, so if you are using a mapping app then they are useful. I use it all the time when I'm troubleshooting GPS data. It's kinda cool to turn on satellite tracking and watch them move across the hemisphere, too.
 
Are you questioning my truthfulness? :D

UBlox units are not as available but they are as economical. You can get integrated UBlox GPS pcbs from China suppliers for about $13 to your door.
https://www.ebay.com/itm/Ublox-NEO-...297?pt=LH_DefaultDomain_0&hash=item2ec7488539

Naw, I trust ya John. :blush: Technically one could simply solder the appropriate pads I suspect on the EF board and use the Ublox chipset. It would be kludged together but should work if one wanted accurate altitude (FWIW). Whad'ya think Cris? Possible? :D
Kurt
 
If you left off the GPS module you could just feed the uBlox' serial data into the Hope RF module. Nothing magical...

I'm not a big fan of the separate antenna and board on the Chinese uBlox modules, I can see the u.fl connectors coming loose under vibration/G's. You could pot them, I suppose, to help prevent this. The Maestro Wireless modules have the antenna soldered on. It IS possible to break one off (I've had a few people manage to do it) but it takes some effort, i.e. a direct hit and/or a decent lawn dart. Better would be to have the NEO module mounted on the board, and have a 50-ohm strip line going to a SMT GPS patch antenna. No wires, just solder.
 
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And it is easy to find complete uBlox modules on Amazon for $25 in single units.

It is fine to have differentiated products but by simply changing the GPS unit the Eggfinder becomes an Eggtracker at basically the same price but with much more value. Particularly for folks interested in the science of rocketry.

Time for a competitor if the vendor chooses to ignore building the best product they can?
 
And it is easy to find complete uBlox modules on Amazon for $25 in single units.

It is fine to have differentiated products but by simply changing the GPS unit the Eggfinder becomes an Eggtracker at basically the same price but with much more value. Particularly for folks interested in the science of rocketry.

Time for a competitor if the vendor chooses to ignore building the best product they can?

No Ken, it doesn't become an EggTracker and still would not be acceptable for records chasing as the unit does not have on board memory. The EF was designed as an economical GPS rocket finding kit. The receiver is not provided with a B/T module and if someone wants to substitute a different GPS module for more accurate altitude reporting, it's a free country and by all means do it. I believe the Ublox unit is twice as much than the Maestro chip that fits on the EF board. Now if Cris feels accurate altitude reporting is a "must" he can redesign the board, flight test and offer one forsale but it won't be at the current price level.

The idea is to "find" the rocket. The max altitude can be read off of the altimeter(s) after recovery. If chasing records that require GPS derived altitude, will have to invest in an approved device. Kurt
 
It is perfectly fine with me that this product stays as is. It is also good that consumers know they have alternatives and the limitations and design choices of products particularly in the sometimes confusing world of radios and GPS.

As far as I know there is no requirement for on board storage for altitude records. Recording telemetry at the base station should be just fine, though perhaps less reliable when hunting for altitude records.
 
As I'm smack dab in the middle of my GPS/Telematics design, I've been conferring with the records committee regarding all the "fine points" of GPS data content. I'm certain the committee considers the GPS engine itself when evaluating approvals. There's no current requirement for VDOP/vAcc in the data, however I will say that my persisted data includes other "fix solution status fields".

Also, if'n it matters for the discussion, here's the TRA Records rules for flights > 30K AGL (requiring GPS data):

3.0 Rules and procedures for GPS Based Flights

3.1 Rockets expected to achieve altitudes of 30,000 MSL and over are required to contain a flyer-supplied GPS unit approved by TRA, (as listed on the TRA website ) to generate altitude data. This data must be recorded and sent to the TRA Competition committee for review and validation.

3.2 Flyers are required to submit the GPS data file as recorded on the in-flight GPS unit for review and validation. Downlinked radio data (i.e. packet radio data) is not sufficient.

3.3 Flyers are required to submit any recorded barometer and accelerometer flight computer data along with the GPS data file for the flight.

3.4 Should the GPS fail to record some fixes, no interpolation will be allowed. Only physical data logged can be used.
 
It is perfectly fine with me that this product stays as is. It is also good that consumers know they have alternatives and the limitations and design choices of products particularly in the sometimes confusing world of radios and GPS.

As far as I know there is no requirement for on board storage for altitude records. Recording telemetry at the base station should be just fine, though perhaps less reliable when hunting for altitude records.

You're wrong. I enquired with TRA HQ and telemetered records via Rf only are not acceptable. If the memory is corrupted the flight is a DNF. Email them yourself.
When I asked, I mentioned the fact I noticed all the units had onboard memory and they confirmed there was a reason.
(I didn't see Jim Amos post above.)

Personally, I wouldn't want wires hanging off my EF for a kluge setup for a little more accurate altitude with a ublox chipset. The BeelineGPS is right on the money for prediction of main deployment when monitoring the altitude with a D72A. If it doesn't happen, you're in trouble unless there's backup.

Now if Cris modifies the board so the Ublox chipset could be mounted there in one piece, that would be another story. I bet some would be willing to pay a premium for more accurate altitude reporting. It still wouldn't be acceptable for records. Kurt
 
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Sigh. Silly rule. Something new it appears. We used to accept them when I was on competition committee.
 
Sigh. Silly rule. Something new it appears. We used to accept them when I was on competition committee.



Question Ken, New for whom? Reason I ask is the "recent prior" approved units for TRA all had onboard memory. They updated the list recently of approved devices because a few more became available. I didn't count but several of the approved units looked like they were out of production but still usable.

Was there a time in the past where an Rf derived record was acceptable? If so that would have been before the Beeline GPS initially was approved one cycle back. Kurt
 
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