Rocket Track - Open Source GPS Tracker for Smartphones

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It has been brought to my attention that the ebay seller who sold the UP501 gps module is currently out of stock. I don't know if this is a temporary issue or not.

In the meantime, there are a couple of workarounds if you are in need of a UP501. In no particular order:

1. Buy a UP501 based shield from someplace like ebay and remove the module. They are actually pretty easy to remove with a little bit of solder wick.

https://www.ebay.com/itm/Fastrax-UP...434?pt=LH_DefaultDomain_0&hash=item33861c95f2

2. Buy a PAM-7Q module from ublox. This should be a drop in replacement for the UP501, but I have not tried this!

https://shop-america.u-blox.com/en/usd/3~106/Positioning-modules/Standalone-positioning/PAM-series

3. You can still buy the UP501 from ublox, but they aren't exactly cheap ($119). See link above.

4. Googling for UP501 turns up a couple of vendors.:

https://www.elecfreaks.com/store/fastrax-up501-gps-receiver-module-with-antenna-uart-p-236.html
https://www.glynstore.com/fastrax-up501-gps-antenna-module/
https://www.pwsstore.com/fastraxup501.aspx

5. Alibaba has quite a few vendors still selling it. I'm hoping that this is where our ebay vendor sources his from and will restock soon.

https://www.alibaba.com/trade/search?fsb=y&IndexArea=product_en&CatId=&SearchText=up501

So all is not lost (yet). A couple of the vendors in #4 actually have decent prices. However once I sell my remaining tx boards I'm not sure if I'll build any more.

If you find any other vendors selling the UP501, please share here.

Thanks!
 
Derek said:
It has been brought to my attention that the ebay seller who sold the UP501 gps module is currently out of stock. I don't know if this is a temporary issue or not.

In the meantime, there are a couple of workarounds if you are in need of a UP501. In no particular order:

1. Buy a UP501 based shield from someplace like ebay and remove the module. They are actually pretty easy to remove with a little bit of solder wick.

https://www.ebay.com/itm/Fastrax-UP...434?pt=LH_DefaultDomain_0&hash=item33861c95f2

2. Buy a PAM-7Q module from ublox. This should be a drop in replacement for the UP501, but I have not tried this!

https://shop-america.u-blox.com/en/usd/3~106/Positioning-modules/Standalone-positioning/PAM-series

3. You can still buy the UP501 from ublox, but they aren't exactly cheap ($119). See link above.

4. Googling for UP501 turns up a couple of vendors.:

https://www.elecfreaks.com/store/fastrax-up501-gps-receiver-module-with-antenna-uart-p-236.html
https://www.glynstore.com/fastrax-up501-gps-antenna-module/
https://www.pwsstore.com/fastraxup501.aspx

5. Alibaba has quite a few vendors still selling it. I'm hoping that this is where our ebay vendor sources his from and will restock soon.

https://www.alibaba.com/trade/search?fsb=y&IndexArea=product_en&CatId=&SearchText=up501

So all is not lost (yet). A couple of the vendors in #4 actually have decent prices. However once I sell my remaining tx boards I'm not sure if I'll build any more.

If you find any other vendors selling the UP501, please share here.

Thanks!
Click to expand...

The PAM 7Q is form factor compatible but not necessarily drop in. The input voltage specs are slightly lower but still compatible with the TX board. Also, the MTK commands don't work since the receiver is Ublox-7 and not MTK. So, you probably want to download the U-center eval software instead of the Fastrax Workbench, to change receiver settings. The Ublox specific software seems to have some more/better features, but I haven't played with it that much. Additionally there is an Android app on the Ublox site for the Ublox chips.

I kludged a TX together with the PAM-7Q using Sparkfun parts, but am still waiting on oshpark to deliver some of Derek's TX boards, to really test it out.

I also emailed Sparkfun about carrying the PAM-7Q as a UP501 replacement and they said they would have their new product guy look into it. Not holding my breath
 
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The input voltage range difference isn't an issue for my tx because the voltage regulator outputs 3.2v for the gps and xbee and the configuration difference shouldn't be a problem for the most part. By default, the PAM-7Q looks to have SBAS enabled unlike the UP501 (one of the two changes the app does to the UP501). The other config change the app does is set the gps to only output the gpgga string to improve battery life. I couldn't find a description of what strings the PAM-7Q outputs, but I'd be surprised if it didn't output gpgga. I didn't see any command to set the output strings in the manual, but I may have missed it.

What strings did you see the PAM-7Q output?
 
Yeah, I checked the v reg specs on your TX board, but if someone were to connect straight to a 4 volt li-po that would probably not be good.

The PAM 7Q defaults to outputting all the NMEA messages. They can be disabled by going to message view (see screenshot) and right clicking on the string you want to kill, then click disable. Also, I found the protocol for turning off NMEA messages on Ublox 6 recievers here, scroll down the page a bit:
https://ukhas.org.uk/guides:ublox6.
I haven't tried them yet by I'd assume they'd be the same for Ublox 7. The Ublox 7 protocol might be found on the Ublox site
but I didn 't try looking very hard, after I found the Ublox 6 info with a quick google search.

NMEA.jpg


edit: I didn't mean the PAM 7Q wouldn't work with your board, just that the manual refers to it as form factor compatible with the UP501 which implies there are some slight differences, and that it isn't a drop in replacement in a general sense, for all applications.
 
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Good find. Here is the the relevant code:

Code: 
// Turning off all GPS NMEA strings apart from GPGGA on the uBlox modules
Serial.print("$PUBX,40,GLL,0,0,0,0*5C\r\n");
Serial.print("$PUBX,40,ZDA,0,0,0,0*44\r\n");
Serial.print("$PUBX,40,VTG,0,0,0,0*5E\r\n");
Serial.print("$PUBX,40,GSV,0,0,0,0*59\r\n");
Serial.print("$PUBX,40,GSA,0,0,0,0*4E\r\n");
Serial.print("$PUBX,40,RMC,0,0,0,0*47\r\n");

Thanks!
 
Here is the face plate in black. I think this is the best color yet:

rx face plate black.jpg

Would anyone actually be interested in purchasing these?
 
Today I ordered a pair of UP501 GPS modules from elecfreaks.com. Free shipping as I was over the minimum purchase. Comes from Hong Kong, we'll see how long it takes for delivery.
 
I assembled one of Derek's Mini TX 1.0 boards this morning. Knowing I had no chance of putting on the 0402 parts by hand, I used solder paste and a friend's reflow toaster oven, which turned out great. I decided to use a Micrel 5219 3.3V regulator to get a wider input voltage range and higher output current since I'm using old Xbee modules, it's pin-compatible with the one Derek uses. Board seems to be working fine except that I will have to tweak the configuration strings to set up the NMEA message frequency, as the Adafruit module uses different strings than the old DIYDrones module I was using before.

Nice job, Derek!
 
Way to go! Did you make a stencil or just squirt some paste on the pads? I've wanted to try the toaster oven soldering trick for a while now.

P.S.

the passives are 0603, not 0402. :)
 
Derek said:
Did you make a stencil or just squirt some paste on the pads?
Click to expand...
I just used a syringe, but if I was doing more than one board with this many parts, I'd make a stencil. They're only $25 for 4 square inches. https://www.pololu.com/product/446

That said, the paste is extremely forgiving of just blobbing it on.

the passives are 0603, not 0402. :)
Click to expand...
Yikes, you're right. Well, I know I wouldn't have a chance with 0402 then.
 
Good to know. I've watched a bunch of videos and read a few sites and I'm tempted to try it but I just need the paste.

Where did you get the solder paste from?

My cm was just in the other day too. I should have asked them for a little bit. Bummer!
 
Derek said:
Where did you get the solder paste from?
Click to expand...
I used Superior 3033-85 no-clean, which is a lead-free paste (Sn96.5/Ag3.5). A co-worker had some and I'm not sure where it came from -- sra-solder.com maybe. Digi-key sells paste and I'd probably go with a leaded type unless I had a strong need to avoid lead -- for example, 5cc of no-clean Sn63Pb37 is about $12.
 
Finished my second tx module (on left). Well I still need to actually solder the GPS receiver to the board, but I verified everything works. The resistor in line with the transmit LED was not making good contact on one side so the tx LED was not working at first, but I put pressure on it with tweezers and hit it with the soldering iron and now all is good. The 603 sized parts aren't too difficult to solder. I pretty much used the same method farsidius describes back in post 11.

transmitters.jpg
 
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Looks great! I'm glad you figured out your led problem.

Derek

P.S. Your pm mailbox is full.
 
Range test.jpgOk, so I did a range test on the transmitter today, with the wire whip antenna.
I'm planning a 12000 ft flight at URRF, so I just wanted to verify I'd be good to two miles.

After work, I asked the building manager where I work for permission to hang the transmitter off the side of the building ( 6 stories). I tied the TX (mounted in a nosecone) to my backback with some Kevlar and let it hang over the side of the roof a couple feet. For the receiver I used a 16 inch rubber ducky rated at 5 dBi gain.

In the attached photo my building is at point 0. My first test was 1.5 miles down the highway at point 1. I got out of my truck, had a clear line of site, and got constant 1 Hz signals.

Second test was 2.3 miles away at point 2. This was a hill off the highway in a church parking lot. I had trees in the way here, and could not see my building, but nonetheless I still got perfect 1Hz updates.

Third stop (point 3) was an overpass about 3 miles away. This location was less elevated than the second spot, and again I had no direct line of sight because of trees in the way. However, I was able to get sporadic reception.

Based on these tests, I'm pretty certain I could get continuous reception w 1Hz updates from 3 miles away if I had direct line of sight. I'd venture to say I may be able to get reception at 4
miles with an unobstructed line of sight.
 
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Did my L3 yesterday at URRF, using Derek's TX PCB and the Ublox PAM 7Q GPS module. Data file during boost is attached. It hit mach 1.1 and about 11200 feet, and landed about 1/2 mile away. Tracking was pretty solid throughout. The GPS lost lock during boost but regained at near apogee. I was going to fly the day before but there must have been others using 900 Mhz trackers, because I was getting a lot of signal dropouts just testing it out with the rocket ten feet away from me, so I decided to not even put it on the pad.

11kft flt 62814.jpg

I screwed up the calibration of the field map I imported into the Ublox software, so I couldn't track it on my screen in realtime, and had to rely on the data points, but I was looking at the sky anyway till I figured it was down. Here is a playback in google earth after the fact, thankfully it made a dogleg left around the trees.

google earth track.jpg
 
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Congrats on the l3! The dropouts the previous day are strange but I'm glad it worked out in the end. The xbees are supposed to be frequency hopping to reduce dropouts due to interference. I wonder if that feature needs to be enabled? I'll try ti dig into this some more.

Derek
 
Having issues with mine. Once rigged to the laptop it drops out. Varying from 20 mins to an hour. Any ideas?

We any closer to this working via BT to an IOS Device?


Sent from my iPhone using Rocketry Forum
 
Pyropetepete said:
Having issues with mine. Once rigged to the laptop it drops out. Varying from 20 mins to an hour. Any ideas?

We any closer to this working via BT to an IOS Device?


Sent from my iPhone using Rocketry Forum
Click to expand...

Are you trying indoor or outside, indoor take a lot more time
 
Area66 said:
Are you trying indoor or outside, indoor take a lot more time
Click to expand...

Both. Sorry it was late and I should of said in the laptop with the software shows as if it's been unplugged.


Sent from my iPhone using Rocketry Forum
 
Pyropetepete said:
Both. Sorry it was late and I should of said in the laptop with the software shows as if it's been unplugged.


Sent from my iPhone using Rocketry Forum
Click to expand...

what has been unplugged? the rx xbee or the tx? are the lights still on the tx and blinking?
 
Derek said:
The xbees are supposed to be frequency hopping to reduce dropouts due to interference.
Click to expand...
As best I can tell they are always hopping between 25 frequencies on 7 hopping patterns. It might be that transmitters with the same hopping pattern (set by the HP parameter) could interfere with each other if they were transmitting with a large duty cycle.
 
Derek said:
has it always behaved this way? are the rx lights still on and flashing?
Click to expand...

Have only started to test fully recently. I put the TX outside in a sandwhich box to keep it protected. This was to test battery duration. All LED's in tx flashing.

RX again LED's flashing and working. Have tried all USB ports. Made 100% sure the system doesn't time out. The system works for a bit then drop pout as if the RX is unplugged.


Sent from my iPhone using Rocketry Forum
 
do you have the 6 pin usb to serial cable?

I know that one member here got a bad rv42 bt module. if you have the cable you can bypass the bt module and see if it still drops out. if it doesn't, then I suspect the bt module is bad.
 

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