Telemetry rig based on PF SL100 and XBee

Advertise with us
rocket sok
the model rocket show
The Rocketry Forum

Help Support The Rocketry Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
What happens if you make your own frequency nobody uses? But otherwise. You have to beware the frequency because some don't get far in the atmosphere. While some do. Antennas are picky on the type of atmosphere your in... Not like your on another planet.
 
Crazy_Rocketeer said:
What happens if you make your own frequency nobody uses? But otherwise. You have to beware the frequency because some don't get far in the atmosphere. While some do. Antennas are picky on the type of atmosphere your in... Not like your on another planet.
Click to expand...

Frequency, transmission power and signal type (phone, data, etc) is regulated by the FCC in the US. I use the consumer devices that broadcast on frequencies and within power limits that don't require a ham license. These frequencies (2.4GHz for the XBee Pro) do just fine here in the atmosphere of planet Earth! But as long as you are using a frequency and power within the FCC guidelines and are appropriately licensed if required, you could use any frequency that was appropriate for the task.
 
Area66 said:
are we talking about this kit ?

https://www.hobbyking.com/hobbyking/store/__42846__fpv_radio_telemetry_kit_915mhz.html
Click to expand...

cerving said:
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:
Click to expand...

This flat panel 10 db gain antenna on a tripod parallel with the ground should easily double the altitude range over a simple whip antenna on the ground station https://www.streakwave.com/itemdesc.asp?ic=ARC-PA0910B01 for only $14. It has a +/- 30 degree beam width so as long as your rocket goes fairly vertical you should not have to make any adjustments to it. You will need an adapter to convert the Type N connector on the antenna to the standard SMA connector on the receiver.

Based solely on the published specs, the wireless modem units look pretty good as the are frequency hoppers and have decent error connection. Local interference should be minimal if you use a gain antenna pointed up.

Bob
 
cerving said:
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:
Click to expand...


Will be nice to have an altimeter with a build-in xbee socket
 
matthewdlaudato said:
That would be very cool and useful. Time to get familiar with some common altimeter chips :cool:
Click to expand...

Cerving altimeter are kit, if he do us an extended board where we can connect a GPS module ( $ 23 ) and a Xbee socket , we are in business for a single boards complete solution. I hate to have wires everywhere.
 
Area66 said:
Cerving altimeter are kit, if he do us an extended board where we can connect a GPS module ( $ 23 ) and a Xbee socket , we are in business for a single boards complete solution. I hate to have wires everywhere.
Click to expand...

I did not know that - now I understand cerving's 'neat product' comment. Wouldn't there also need to be some flow control logic to control which device (GPS or altimeter) was sending data to the XBee at a given time? Otherwise you'd have two competing signals on the XBee DIN.
 
Area66 said:
Cerving altimeter are kit, if he do us an extended board where we can connect a GPS module ( $ 23 ) and a Xbee socket , we are in business for a single boards complete solution. I hate to have wires everywhere.
Click to expand...

look at the various quadrocopter flight computers that are readily available for not a lot of money. I have one with an arduino mega, 3 axis accel, g and compass sensor, barometer, gps and xbee socket. The accel range probably won't work for us, but everything else should. It is pretty much a plug and play solution.
 
cerving said:
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.
Click to expand...
I agree that the 3DR Radio clone system from HK (also found on eBay for about the same price when HK postage is included in their price) combined with the Eggtimer is the most economical path. In my small mount of reading thus far on the 3DR system, it appears that its data packets can include a RSSI (Received Signal Strength Indication) from both ends of the link. Could that data be used for RDF with a directional antenna at the ground station even though the link is FHSS (Frequency Hopping Spread Spectrum), something that would normally preclude that?
 
FYI, according to my reading in the various DIY drone and FPV forums, this is the GPS module with rave reviews, extremely sensitive even indoors with very fast satellite acquisition compared to others:

https://www.ebay.com/itm/High-perfo...074?pt=LH_DefaultDomain_0&hash=item27cf28c8b2

Note that I'm speaking of the reputation of that module and not this specific source for it although this source has sold 652 of them.
 
Winston said:
FYI, according to my reading in the various DIY drone and FPV forums, this is the GPS module with rave reviews, extremely sensitive even indoors with very fast satellite acquisition compared to others:

https://www.ebay.com/itm/High-perfo...074?pt=LH_DefaultDomain_0&hash=item27cf28c8b2

Note that I'm speaking of the reputation of that module and not this specific source for it although this source has sold 652 of them.
Click to expand...

I have one of those , but their something anoying, it need to source of power

View attachment SCHEMATIC1 _ UP501.pdf
 
Winston said:
FYI, according to my reading in the various DIY drone and FPV forums, this is the GPS module with rave reviews, extremely sensitive even indoors with very fast satellite acquisition compared to others:

https://www.ebay.com/itm/High-perfo...074?pt=LH_DefaultDomain_0&hash=item27cf28c8b2

Note that I'm speaking of the reputation of that module and not this specific source for it although this source has sold 652 of them.
Click to expand...

That is the gps module I use in my tracker. It works very well. You can get them from mouser for a little more.
 
Winston said:
I agree that the 3DR Radio clone system from HK (also found on eBay for about the same price when HK postage is included in their price) combined with the Eggtimer is the most economical path. In my small mount of reading thus far on the 3DR system, it appears that its data packets can include a RSSI (Received Signal Strength Indication) from both ends of the link. Could that data be used for RDF with a directional antenna at the ground station even though the link is FHSS (Frequency Hopping Spread Spectrum), something that would normally preclude that?
Click to expand...

it is too bad that hk doesn't sell the radios individually. I'd really like two of the non usb radios (the air module).
 
Derek said:
That is the gps module I use in my tracker... You can get them from mouser for a little more.
Click to expand...
Unfortunately Mouser didn't have them the last time I checked (EOL and deleted from the site), that Ebay seller is the only source I could find.
 
Derek said:
look at the various quadrocopter flight computers that are readily available for not a lot of money. I have one with an arduino mega, 3 axis accel, g and compass sensor, barometer, gps and xbee socket. The accel range probably won't work for us, but everything else should. It is pretty much a plug and play solution.
Click to expand...

Good tip. Just my preference though, I prefer more DIY on my electronics projects, so I'd probably not go for something like this.
 
mikec said:
Unfortunately Mouser didn't have them the last time I checked (EOL and deleted from the site), that Ebay seller is the only source I could find.
Click to expand...

darn, you're right! that is a serious bummer. I'm going to have to respin the board now. grrrr. :(
 
Area66 said:
I have one of those , but their something anoying, it need to source of power
Click to expand...

you don't actually need two power sources. just tie the two power pins together and it will work just fine. the second battery allows it to start up faster, but in my experience the up501 is so fast and it only saves you 20 - 30 seconds.
 
Derek said:
you don't actually need two power sources. just tie the two power pins together and it will work just fine. the second battery allows it to start up faster, but in my experience the up501 is so fast and it only saves you 20 - 30 seconds.
Click to expand...

Just to make sure ; you means to connect VDD and VDD_B on the same positive connector ?
 
On XBee vs the 3DR Radio system (and it's clones), besides the big price difference. I've read comments elsewhere that the XBees are in some unspecified way more configurable and can implement encryption, but the cheaper 3DR clones have everything I'd need:

The 3DR Radio telemetry system is designed as an open source Xbee replacement radio set, offering a lower price, longer range and superior performance to Xbee radios. It's available in 915Mhz and 433Mhz; and in the following configurations: serial board (for the air) and USB (for the ground).

Hardware Features and Specifications:

Very small size
Light weight (under 4 grams without antenna)
Available in 915MHz or 433MHz variants
Receiver sensitivity to -121 dBm
Transmit power up to 20dBm (100mW)
Transparent serial link
Air data rates up to 250kbps
Range of approx 1 mile
MAVLink protocol framing and status reporting
Frequency hopping spread spectrum (FHSS)
Adaptive time division multiplexing (TDM)
Support for LBT and AFA
Configurable duty cycle
Built in error correcting code (can correct up to 25% data bit errors)
Demonstrated range of several kilometers with a small omni antenna
Can be used with a bi-directional amplifier for even more range
Open source firmware
AT commands for radio configuration
RT commands for remote radio configuration
Adaptive flow control when used with APM
Based on the HopeRF HM-TRP radio module, featuring an SiLabs Si1000 RF microcontroller

https://diydrones.com/profiles/blogs/announcing-the-3dr-radio-telemetry-system
 
Derek said:
it is too bad that hk doesn't sell the radios individually. I'd really like two of the non usb radios (the air module).
Click to expand...
If history is a guide, HK's never going to listen to suggestions like that, so I'm going to suggest it to the eBay seller I'm ordering one set from.

As an aside, for any eBay order shipped from China to the US, either make sure it is to be shipped by ePacket by searching for that term within the eBay ad (too many don't explicitly state it under "shipping" at the top of their ad) or, if it isn't mentioned, praise that shipping method with the seller when ordering. It may cost just a very small amount more, still trivial, and it is really worth it. Stuff I order with ePacket delivery gets here much, much faster than typical shipments from China.

"ePacket Service is a trilateral agreement between US Postal Service, eBay, China, and Hong Kong Post offices to offer China and Hong Kong eBay sellers a fast but low cost shipping option. This service offers local pick-up service, label printing, online tracking and pre-customs declaration for a 7 to 10-day guaranteed delivery period."
 
bobkrech said:
This flat panel 10 db gain antenna on a tripod parallel with the ground should easily double the altitude range over a simple whip antenna on the ground station https://www.streakwave.com/itemdesc.asp?ic=ARC-PA0910B01 for only $14. It has a +/- 30 degree beam width so as long as your rocket goes fairly vertical you should not have to make any adjustments to it. You will need an adapter to convert the Type N connector on the antenna to the standard SMA connector on the receiver.
Bob
Click to expand...
Man, that is cheap! A flat panel from the same manufacturer with only 2.5dB more gain is $42. That particular 10dB model must be extremely popular thereby providing the economy of scale and resulting in a much lower price. Full specs here:

https://www.antennas.com/wp-content/uploads/2011/12/ARC-PA0910B01_DS_090711.pdf
 
Winston said:
On XBee vs the 3DR Radio system (and it's clones), besides the big price difference. I've read comments elsewhere that the XBees are in some unspecified way more configurable and can implement encryption, but the cheaper 3DR clones have everything I'd need:

The 3DR Radio telemetry system is designed as an open source Xbee replacement radio set, offering a lower price, longer range and superior performance to Xbee radios. It's available in 915Mhz and 433Mhz; and in the following configurations: serial board (for the air) and USB (for the ground).

Hardware Features and Specifications:

Very small size
Light weight (under 4 grams without antenna)
Available in 915MHz or 433MHz variants
Receiver sensitivity to -121 dBm
Transmit power up to 20dBm (100mW)
Transparent serial link
Air data rates up to 250kbps
Range of approx 1 mile
MAVLink protocol framing and status reporting
Frequency hopping spread spectrum (FHSS)
Adaptive time division multiplexing (TDM)
Support for LBT and AFA
Configurable duty cycle
Built in error correcting code (can correct up to 25% data bit errors)
Demonstrated range of several kilometers with a small omni antenna
Can be used with a bi-directional amplifier for even more range
Open source firmware
AT commands for radio configuration
RT commands for remote radio configuration
Adaptive flow control when used with APM
Based on the HopeRF HM-TRP radio module, featuring an SiLabs Si1000 RF microcontroller

https://diydrones.com/profiles/blogs/announcing-the-3dr-radio-telemetry-system
Click to expand...

there are a few differences between the 3dr and xbee radios, other than price.

the biggest (imo) is output power. the 3dr is 100 mw, the xbee pro 900hp is 250 mw.

the 3dr has a much better configuration gui. digi's sucks in comparison and as of right now you can't upgrade or change the config over the air. this can be a pain if you need to make changes to the transmitter's radio.

they take up about the same amount of space, but the xbees are short and wide, the 3dr are narrower and longer. it you want to put one in a skinny rocket, the 3dr has an advantage.

imo, the pin layout of the xbee provides a much more robust connection to the board.

you can get the xbee with a wire antenna. you would have to modify the 3dr if you needed a wire antenna.

the xbees can form a mesh network significantly increasing the range.

those are the most significant differences I can think of at the moment. I've used both in my tracking systems, but I currently use the xbees. I just wish digi got their act together and fixed their crappy config gui.
 
Derek said:
I just wish digi got their act together and fixed their crappy config gui.
Click to expand...

I don't even use their UI anymore - wrote an Arduino sketch to talk to the XBee that uses the AT commands directly through the console.

For my application over the air config isn't something I need - not sure why I would ever need this for telemetry applications. Do you have a rocketry use case where this is helpful?
 
Derek said:
as of right now you can't upgrade or change the config over the air. this can be a pain if you need to make changes to the transmitter's radio.
Click to expand...

I don't think that's the case. I've never tried it, but according to the XBee manual, you can send and activate config changes to a remote device by using API mode and explicitly addressing the node you want to reach.
 

Similar threads

J
Radio Questions for Telemetry Transmission
Replies
17
Views
2K
mikec
mikec
conneryc
People using the Eggtimer USB receiver - What are you mounting it in?
Replies
1
Views
239
jgarbus
J
G
Recommendations for Software for Real Time Telemetry Plotting (Python is too slow?)
Replies
29
Views
2K
tHoagland
T
Dave A
AltAcc2C Woes
Replies
8
Views
584
fyrwrxz
fyrwrxz
diyaerospace
Best Radio Module for Telemetry?
Replies
14
Views
5K
waltr
W

Latest posts

Back
Top