Telemetry rig based on PF SL100 and XBee

[matthewdlaudato]

Hi, new to the forum but not to rocketry. I've seen lots of interest from my local clubs (I'm a CMASS and MMMSCLUB member) on the telemetry rig that I've been flying on my Super DX3. It's pretty basic, but it gives me realtime plots of altitude, so that's somewhat cool.

I wrote it up on my personal blog (see technistas.com/rockets/), but here's the basics.

First, a screen capture of what I see during a flight:



The setup is as follows:
Air station: PerfectFlite SL100 and an XBee Pro 60mw transceiver. Data out of SL100 is connected to DIN of the onboard XBee. XBee is mounted on a Sparkfun level shifter board (but I don't actually need level shifting, I just had one laying around). Ground of SL100 data port is connected to XBee ground for common signal ground. XBee immediately transmits any data that enters on its DIN pin.
Ground Station: Another XBee mounted on a Sparkfun USB adapter board, connected via USB cable to my Dell laptop, and paired to the onboard XBee. The XBee shows up as a serial device on the laptop. Ground software is written in Processing, the open source computing platform. It's about 100 lines of code. See my github repository for the code. As data comes in (about 20 data points per second), the ground software reads it from the XBee serial port and plots it.

Like I said, not too fancy, but fairly cool. The main advantage over other approaches that I considered is that I don't need a separate microcontroller. At one point I had the ground station using an Arduino Uno, but I eliminated that in favor of simply connecting the XBee directly to the laptop and using software - much simpler and less error prone, plus my laptop using Processing has more than enough horsepower to handle the 20 data points per second that stream in.

I've obtained data on flights up to 3300' and hope to push the one mile published limit of the XBees in the spring.

--
Matt Laudato
NAR# 91867
L1 8/17/2013 Madcow Super DX3 on H152
L2 11/2/2013 Madcow Super DX3, modified for Dual Deploy, on J285

 

[XrayLizard]

very nice

 

[Area66]

Thanks for posting the code, I will give a try

 

[dlb]

I'm getting ready to use these for a high altitude flight.

https://www.digi.com/products/wireless-wired-embedded-solutions/zigbee-rf-modules/point-multipoint-rfmodules/xtend-module

40 miles, WOW

 

[xenon]

I'm getting ready to use these for a high altitude flight.

https://www.digi.com/products/wireless-wired-embedded-solutions/zigbee-rf-modules/point-multipoint-rfmodules/xtend-module

40 miles, WOW

That's amazing. I previously had a pair of xbee pros but burned them out stupidly before I got any use out of them. These look really fun for a lot of things

 

[matthewdlaudato]

Too pricey for me, but they look very cool. If I upgrade it will likely be to something like the XBee-Pro 900 XSC - 9 mile range with a simple wire antenna for about $66 each.

 

[cerving]

I've gotten a mile out of the $29.99 Hobby King 3DR clones. I'm pretty sure it would work to about 7K, but I haven't had a chance to test it at that altitude yet. You can feed them with anything that puts out logic-level serial data, that includes the SL100, I believe the RRC3, and the Eggtimer (of course, which is what I used).

 

[matthewdlaudato]

I've gotten a mile out of the $29.99 Hobby King 3DR clones. I'm pretty sure it would work to about 7K

The XBee Pro 60mw version I use ran $34 from Sparkfun, so not bad. I suspect I could squeeze more than the stated 1 mile limit out of them, but not sure how much more. Guess I will have to build a really high flier to test!

BTW great conversation everyone on this thread.

BTWW the graph I included above is from the DX3 on a CTI I170. I don' yet have the software plot the time scale - flight time for everything you see there was around 53 seconds. I'll get that coded up over the winter.

 

[cerving]

You can use Excel or one of its free clones to plot a time vs altitude graph, if you save the data to a .csv file.

 

[matthewdlaudato]

You can use Excel or one of its free clones to plot a time vs altitude graph, if you save the data to a .csv file.

I do save the data in a text file, and have plotted it in Excel post-flight, but what I was talking about is the real-time plot as the flight is happening, which is the purple/black plot you see in my original post. It should be a small amount of coding in Processing to add a horizontal axis with a time scale.

 

[XrayLizard]

real time is where the fun is at

course ya need someone to watch the rocket....

 

[Area66]

Hi Matt, what 3.3 power source are you using for the Xbee in the rocket ?

 

[matthewdlaudato]

course ya need someone to watch the rocket....

Yup, I do a lot of turning my head back and forth - screen, rocket, screen. Real-time is way fun!

 

[matthewdlaudato]

Hi Matt, what 3.3 power source are you using for the Xbee in the rocket ?

I use 2xAA Gerard. The XBee can operate with a supply voltage 2.8-3.4v and a fresh AA is 1.6v per my measurements, so it works out fine.

 

[Area66]

I use 2xAA Gerard. The XBee can operate with a supply voltage 2.8-3.4v and a fresh AA is 1.6v per my measurements, so it works out fine.

thanks I was thinking to use this regulator and here my schematic ( oups I forget the connector betwen the J2 - and the battery - ) , but I will give a try to 2 x 1.5V eventually I will connect a GPS on the Xbee too

 

[matthewdlaudato]

thanks I was thinking to use this regulator and here my schematic ( oups I forget the connector betwen the J2 - and the battery - ) , but I will give a try to 2 x 1.5V

I had thought about using a single battery and a level shifting board to mount the XBee on, but ultimately decided to fly paranoid and use separate power supplies. A bit more crowded on the sled. I also had some trouble with using the Sparkfun level shifting board - when I powered it off of 5v, it seemed to hold the data out pin on the altimeter high at 5v, and thus I was never able to get a signal. I will probably experiment over the winter with other configurations. I like your setup and think it should work though.

 

[Crazy_Rocketeer]

Hi, new to the forum but not to rocketry. I've seen lots of interest from my local clubs (I'm a CMASS and MMMSCLUB member) on the telemetry rig that I've been flying on my Super DX3. It's pretty basic, but it gives me realtime plots of altitude, so that's somewhat cool.

I wrote it up on my personal blog (see technistas.com/rockets/), but here's the basics.

First, a screen capture of what I see during a flight:

View attachment 154138

The setup is as follows:
Air station: PerfectFlite SL100 and an XBee Pro 60mw transceiver. Data out of SL100 is connected to DIN of the onboard XBee. XBee is mounted on a Sparkfun level shifter board (but I don't actually need level shifting, I just had one laying around). Ground of SL100 data port is connected to XBee ground for common signal ground. XBee immediately transmits any data that enters on its DIN pin.
Ground Station: Another XBee mounted on a Sparkfun USB adapter board, connected via USB cable to my Dell laptop, and paired to the onboard XBee. The XBee shows up as a serial device on the laptop. Ground software is written in Processing, the open source computing platform. It's about 100 lines of code. See my github repository for the code. As data comes in (about 20 data points per second), the ground software reads it from the XBee serial port and plots it.

Like I said, not too fancy, but fairly cool. The main advantage over other approaches that I considered is that I don't need a separate microcontroller. At one point I had the ground station using an Arduino Uno, but I eliminated that in favor of simply connecting the XBee directly to the laptop and using software - much simpler and less error prone, plus my laptop using Processing has more than enough horsepower to handle the 20 data points per second that stream in.

I've obtained data on flights up to 3300' and hope to push the one mile published limit of the XBees in the spring.

--
Matt Laudato
NAR# 91867
L1 8/17/2013 Madcow Super DX3 on H152
L2 11/2/2013 Madcow Super DX3, modified for Dual Deploy, on J285

Can't you make xbee have more power? Like an amplifier. I've seen rc planes go 20 miles before with amplifiers.
Also why can't you use one of these? https://www.robotshop.com/en/seeedstudio-433mhz-rf-long-distance-transmitter-receiver.html

 

[mikec]

The XBee Pro 60mw version I use ran $34 from Sparkfun...

FYI, you can buy a 250 mW Pro 900 XSC (range 6-9 miles) from Digikey or Mouser for $39. Sparkfun's pricing on Digi products is pretty inflated.

 

[matthewdlaudato]

Can't you make xbee have more power? Like an amplifier. I've seen rc planes go 20 miles before with amplifiers.
Also why can't you use one of these? https://www.robotshop.com/en/seeedstudio-433mhz-rf-long-distance-transmitter-receiver.html

The modules you mention look interesting. Data sheet says 2km range though, which is about what my current rig should do. Have you worked with them before? (Easy on the quoting there, CR - that was my whole post you quoted!)

 

[matthewdlaudato]

FYI, you can buy a 250 mW Pro 900 XSC (range 6-9 miles) from Digikey or Mouser for $39. Sparkfun's pricing on Digi products is pretty inflated.

True enough. I've just started using Digikey as a vendor so might do more biz with them.

 

[bobkrech]

Can't you make xbee have more power? Like an amplifier. I've seen rc planes go 20 miles before with amplifiers.
Also why can't you use one of these? https://www.robotshop.com/en/seeedstudio-433mhz-rf-long-distance-transmitter-receiver.html

You have to be careful about quoted range. Your example has a max range of 2 km = 1.2 miles and that's quite optimistic.

1.) Range is dependent on transmitter power, frequency, obstacles and the receiver antenna gain and directionality.
2.) Using a receiver that uses an external directional antenna with gain can double or triple the range of legal non-licensed transmitters compared to the simple 1/4 wave antennas provided without increasing the transmitter power.
3.) You should be aware that there are FCC mandated power limitations for different frequency bands and modes of transmission to prevent interference by unlicensed users. While you can buy electronics that have higher power than is legally permitted or requires a FCC license, the FCC is cracking down on the use of these transmitters. If you are found using a transmitter illegally, you can be fined up to $30,000.
4.) Getting a ham license is easy and with a ham license you have many more options, and can use higher transmitter power.

Bob

 

[matthewdlaudato]

Hi Bob, great info as usual. One reason I like the XBees that I'm currently using is that they are consumer devices, don't require a license and work as advertised. That said, I'm almost certainly getting my Tech license over the winter, and that will open up a few doors. Realistically though, I don't see flying anything much above 5000' in the near future, so my rig should be fine for the time being.

- Matt

 

[Area66]

I'm gone launch a rocket with the setup on my drawing next saturday to see how it work

 

[Area66]

I ordered a vacuum pump, I will be able to test the thing and the Process apps in lab

 

[matthewdlaudato]

I ordered a vacuum pump, I will be able to test the thing and the Process apps in lab

I used my shop vac in the garage with a piece of 1/2" tubing duct taped to the end of the nozzle. Taped off 3 of the 4 vent holes in the altimeter bay, turned on the XBee, the altimeter, and the vac, then put the tubing on the remaining hole. I got 200 simulated feet of altitude and was able to verify that data was sent to the ground station and plotted. Let me know how your tests go.

 

[Area66]

It come from Ontario, is they ship it tomorrow I should have it this week

 

[Area66]

Where do you get the connector for the Stratologger data connector ?


EDIT ; found it they sell it on Perfecflight website at $ 2.67 each, I ordered , after some search it's look like a Micro JST 1.25 5-Pin Connector

 

[cerving]

You'll need two of them... it's going to be $78 plus shipping and probably tax. That's why the $29.99 3DR clones from HK is a good deal, you get both units and they come with stick antennas.

FYI, you can buy a 250 mW Pro 900 XSC (range 6-9 miles) from Digikey or Mouser for $39. Sparkfun's pricing on Digi products is pretty inflated.

 

[Area66]

You'll need two of them... it's going to be $78 plus shipping and probably tax. That's why the $29.99 3DR clones from HK is a good deal, you get both units and they come with stick antennas.

are we talking about this kit ?

https://www.hobbyking.com/hobbyking/store/__42846__fpv_radio_telemetry_kit_915mhz.html

 

[cerving]

Yes. I've flown them to over 5,000' and got a time/altitude curve that matched the baro data, I'm pretty sure that they'd make it to about 7,000' with the included antenna but I have not had a chance to fly it that high yet. With a directional panel antenna on the receiver end, 10,000' may be possible.

The Hope RF HM-TRP modules are pretty nice, they'd make a good basis for a neat product... :wink:

are we talking about this kit ?

https://www.hobbyking.com/hobbyking/store/__42846__fpv_radio_telemetry_kit_915mhz.html