New tracker range test result

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I thought it was stated 137,000 feet with > 90% position recovery of positions at the receiver. Correct me if I miss stated.
Pretty impressive opening test if you ask me. Kurt
 
I thought it was stated 137,000 feet with > 90% position recovery of positions at the receiver. Correct me if I miss stated.
Pretty impressive opening test if you ask me. Kurt

That is correct - and that with only a ~2" antenna on both the transmitter and receiver...
 
Impressive numbers.

Yup, I foresee someone will eventually come up with an easy "live-tracking-on-a-map" algorithm/solution the masses can use as opposed to the P.I.T.A. hacked together setups I've come up with.

Manual input works fine as long as one is certain of their units and will likely suffice with 95% or greater of sport flying. I think we're fast
approaching the day when flying out of sight rockets with GPS tracking is going to be the rule rather than the exception. That has the potential to increase flier satisfaction and retention in the
hobby. I wonder how many in the past got discouraged and quit after losing pricey hardware once or twice. Only the hardcore enthusiasts are likely to "hang on" after losing a lot of motor cases.
(Or they got "smart" and invested in a tracking setup.)

RDF is likely to be relegated to backup tracking or instances where a GPS tracker just doesn't fit in the project. That Ham stuff on 70cm for RDF can be cost effective if one has a radio receiver with a true
signal strength meter, get a $25-$31 offset attenuator: https://www.west.net/~marvin/k0ov.htm and either buy a Yagi or make one.

Kurt
 
Is it possible to operate two ground stations receiving data from the same rocket? I do this with my Eggfinders, I have an EF RX back at my camp logging real-time data on my computer, and then the handheld unit on me to track the flight and navigate to the rocket. I realize this unit will do its own logging, but I'd prefer to have recording on the ground also in case it gets lost or crashes.

Oops, missed this question the first time around. Yes, the plan is for multiple ground stations to be able to track the same rocket.

Currently we're working on the infrastructure that will let us roll out new software features and automatically distribute them to all the users. The plan is for you to be notified on your phone that an update is available, and then with a single tap the microcontrollers on both units will get updated in less than a minute. That will allow us to start the first production run.
When we get that done then I'll be working on the protocols for multiple ground stations and multiple users.
 
That is correct - and that with only a ~2" antenna on both the transmitter and receiver...

And with only 25 mW transmit power.

...And there was two feet of snow and it was uphill both ways!
Some say you can still hear it transmitting, to this day...:rolleyes:
 
I find with B/T pairing of another product's ground station, it helps if one device is paired to the tablet/phone and then walk away with the second B/T receiver with its device and pair out of B/T range on that pair. I had a bear of a time trying to get two ground
stations to work otherwise. The second tablet seemed to be seeing the first paired set and trying to mess with that. I was using two ground stations to test two different terminal tracking programs. Might be just particular to the product I was using but
keep this characteristic in the back of one's mind.

Always ground test and practice with a system (no matter what you use) ad nauseum before going out to fly it. Will save you a lot of grief. Kurt
 
I find with B/T pairing of another product's ground station, it helps if one device is paired to the tablet/phone and then walk away with the second B/T receiver with its device and pair out of B/T range on that pair. I had a bear of a time trying to get two ground
stations to work otherwise. The second tablet seemed to be seeing the first paired set and trying to mess with that. I was using two ground stations to test two different terminal tracking programs. Might be just particular to the product I was using but
keep this characteristic in the back of one's mind.

Always ground test and practice with a system (no matter what you use) ad nauseum before going out to fly it. Will save you a lot of grief. Kurt

Kurt, I've been thinking about this already and think I can make something that makes this easier. I was more concerned with a user powering up and seeing 10,000 Featherweight Trackers at a launch to pair to :)smile:) but think my method will work for your case of two tablets and two ground stations as well.

Right now, I am working on the 'update GS/TRK firmware over the BTLE' link so we can get to production sooner. When that is complete I will have some time to work more back on making the BTLE intuitive and 'solid'. I'll let you know when I can confirm my suspicions / methods...

And again - thanks always for your inputs/thoughts/concerns! :smile:
 
You're welcome. The easier this becomes, the more folks might consider larger motors to tickle the waivers at whatever venue they fly. Though some might
consider the "finding" of a rocket an acceptable "challenge", I tell you that gets old quickly and I just as soon find the project expediently and go on to launch the next one. Those of us stuck in the Midwest with the fickle weather and seasonal venues have a tendency to want to fly as many rockets as we can when we can.

Kurt
 
The easier this becomes, the more folks might consider larger motors to tickle the waivers at whatever venue they fly.

Yes, I know I will be more aggressive in my rockets/motors/flights if I know I can easily find them afterwards....!
 
LoRa technology is certainly interesting. You can have more than 1 user on the same frequency with different spreading factors and they don't interfere with each other. And it looks like they are building a network using this technology (LoRa Alliance). Hopefully that won't mess things up for your tracker product.
 
LoRa technology is certainly interesting. You can have more than 1 user on the same frequency with different spreading factors and they don't interfere with each other. And it looks like they are building a network using this technology (LoRa Alliance). Hopefully that won't mess things up for your tracker product.

I wonder if the electric meter on my house will know where my rocket is...? :smile:
 
LoRa technology is certainly interesting. You can have more than 1 user on the same frequency with different spreading factors and they don't interfere with each other. And it looks like they are building a network using this technology (LoRa Alliance). Hopefully that won't mess things up for your tracker product.

For a LoRa receiver to start reacting to a signal, it has to be on the same frequency (out of 50-100 typical channels), with the same selected bandwidth (out of 3 typical choices), and the right spreading factor (out of 7 typical choices) and the same coding rate (out of 4 choices, though most people will probably opt for 1 of the 4 options). So the chances of an unintentional connection are pretty small. Transmissions on a different frequency won't affect the receiver at all, while transmissions that are on the same frequency but don't match up the other three factors just look like noise to the receiver, reducing the receive sensitivity by a few dB during the overlap in transmission.

If a rocket with a LoRa receiver does pick up an unwanted transmission, it can start ignore the signal because it will see that the packet doesn't contain the information specific to the user's ground station that it will be looking for.

The LoRaWAN (LoRa Wide Area Network) protocol is designed for users in a relatively dense area communicating with centralized gateways that will cover several square miles, and then those gateways send data back to the internet. There are a number of details about LoRaWAN that would prevent us from implementing several features that we plan to include, so that's why we're rolling our own protocol.
 
What should be the last prototype before production:

Top:
ui6Etw5.jpg

Dang, I soldered the antenna on a little crooked. (These prototypes, unlike the production units, are hand-assembled)

Bottom:
TDzpXsb.jpg


Edge:
YuzNhuM.jpg


By popular request, the mounting holes have round-number locations. Both of them are 0.25" from the centerline vertically and 1.00" apart horizontally.

I should have pictures of an assembled ground station next week.
 
Awesome. It looks like for onboard data logging, you'd need a separate OpenLog or similar..? Does the u-blox have recording space you can use?
 
Adrian is probably typing also but I'll just say "no, it's there - you just don't see it".. :smile: ..but you are on the right track...
 
Awesome. It looks like for onboard data logging, you'd need a separate OpenLog or similar..? Does the u-blox have recording space you can use?

There’s 96 kB of built-in non-volatile storage for data logging on the board. Not all of the software for the logging functionality has been written yet, but we’ve gotten far enough along to know that the hardware will support it.
 
There’s 96 kB of built-in non-volatile storage for data logging on the board. Not all of the software for the logging functionality has been written yet, but we’ve gotten far enough along to know that the hardware will support it.
That'll do!
 
I can’t wait. This is really promising. I am especially glad to see it will work with iOS.
 
I can’t wait. This is really promising. I am especially glad to see it will work with iOS.
Me too! CC waiting for it to come up for sale.

Thanks.


Any expected price yet and if I missed it is that an RP SMA connector or SMA? Kurt

It's SMA.

I'm getting close to setting a price but it will depend on the electronic assembly cost, which I will find out after I send them the released engineering data. There's a little more testing we need to do before that happens.
 
Thanks.




It's SMA.

I'm getting close to setting a price but it will depend on the electronic assembly cost, which I will find out after I send them the released engineering data. There's a little more testing we need to do before that happens.

Whoopee, I have a bunch of plain SMA Linx antennas from prior projects. Have a few RP-SMA but the bulk is SMA. (I had the board connectors an hand so that's what I used on projects as opposed to RP-SMA.) Kurt
 
Sounds like a great system. Any chance it will be out in time for Christmas?

I think so. I was hoping to make it order-able this weekend, but we're running a little behind on that. I may have the new website with more information up this weekend, though. No promises on Christmas until I test a production unit, but I'm expecting that to be in mid-December.
 
Just in time so I can integrate it into the 38mm Mongoose and maybe the sustainer of the Nike Apache if I end up with one of those. Any teaser on pricing?


Tony
 
Last edited:
What should be the last prototype before production:

Top:
ui6Etw5.jpg

Dang, I soldered the antenna on a little crooked. (These prototypes, unlike the production units, are hand-assembled)

Bottom:
TDzpXsb.jpg


Edge:
YuzNhuM.jpg


By popular request, the mounting holes have round-number locations. Both of them are 0.25" from the centerline vertically and 1.00" apart horizontally.

I should have pictures of an assembled ground station next week.
Beautiful work! I want!
 
Just in time so I can integrate it into the 38mm Mongoose and maybe the sustainer of the Nike Apache if I end up with one of those. Any teaser on pricing?
Tony

$130 per tracker.

A tracker can be used at either end of the link. An optional ground station enclosure that includes a large battery, battery charger and external switch will go for $40. More photos and info soon.

I just placed an order for a small production run, with an expected delivery time in time for Christmas. I’m tempted to open it up for pre-orders but my better judgement says to wait until they are ready to ship. I should have a new and improved Featherweight Altimeters website up tomorrow with more information.

Update: Here's a picture of a bare tracker and a tracker inside the new powered ground station enclosure. The ground station enclosure has a door on the underside that gives you access to the battery without unscrewing anything. This should make it straightforward for using the enclosure for charging batteries at both ends of the link.
TIjOlK5.jpg


BTW Thanks to Mark Haynes at StickerShock for making a nice label at a reasonable price.
 
$130 per tracker.

A tracker can be used at either end of the link. An optional ground station enclosure that includes a large battery, battery charger and external switch will go for $40. More photos and info soon.

I just placed an order for a small production run, with an expected delivery time in time for Christmas. I’m tempted to open it up for pre-orders but my better judgement says to wait until they are ready to ship. I should have a new and improved Featherweight Altimeters website up tomorrow with more information.

So $260 for the pair? Kurt
 

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