Which wireless links when using Spektrum 2.4GHz Tx/Rx?

Wireless & IoT
1

Hi…new to this forum.

I am looking into a wireless serial modem to add to a PIC-based autopilot. I use a Spektrum 2.4GHz Tx/Rx, so expect that the 2.4GHz modems (like Xbee) are not a good idea. I see some HAC units on SparkFun, but in looking at the Forum, there seems to be very little info on them…some info looks like people have problems with them.

Any recommendations on a long-range serial modem that might work with a 2.4GHz Rx/Tx system?

500-1000m range, 12-96K baud rates, simple to use!

Thanks

John

2

one of the IEEE 802.15.4 plug and play modules, such as Digi XBee sold here, or Jennic if you are geeky

1000m is viable if you have line of sight an if one end has enough antenna gain, say, 8dBi. Do the link budget math. If non-line-of-sight, don’t expect more than 30-100m

Alternative, much more expensive: Digi’s 868/900MHz modems. Higher power, lower freq = longer range but still vulnerable to non-line-of-sight such as a thick stand of trees.

3

Thanks…good info.

I guess the first order question is compatibility with a 2.4Ghz RC Tx/Rx .

I have a 2.4GHz wireless camera that I have checked interference with the Rx and it does effect it. So I assume I need to stay away from 2.4GHz modems…Pity since that seems to be where all the action is. I douubt I’m alone in this problem.

Anyone out there running RF modems with 2.4GHz radio control systems? Any recommendations?

Thanks

4

[quote=I have a 2.4GHz wireless camera that I have checked interference with the Rx and it does effect it. So I assume I need to stay away from 2.4GHz modems…Pity since that seems to be where all the action is. I douubt I’m alone in this problem.

Anyone out there running RF modems with 2.4GHz radio control systems? Any recommendations?[/quote]

I have same problem with a 2.4ghz wireless camera, I just got into using the Xbee Pro wireless radios my self, If someone was worried about interference, why not use just the wireless xbee radio for both your autopilot control and manual control. I know most 2.4ghz and old school FM radios still use PPM (trainer port). It is easy to decode, in which you could piggy back that information on top with anything eles you might be needing to transmit to the airplane. But be ware of any unwanted latency’s…

thats my two cents!

5

John_Mac:
Hi…new to this forum.

I am looking into a wireless serial modem to add to a PIC-based autopilot. I use a Spektrum 2.4GHz Tx/Rx, so expect that the 2.4GHz modems (like Xbee) are not a good idea. I see some HAC units on SparkFun, but in looking at the Forum, there seems to be very little info on them…some info looks like people have problems with them.

Any recommendations on a long-range serial modem that might work with a 2.4GHz Rx/Tx system?

500-1000m range, 12-96K baud rates, simple to use!

Thanks

John

500-1000m with 2.4GHz will require some directional antennas with quite a bit of gain. You can do the math.

If you live in Japan or certain EU countries, there are very restrictive limits on radiated power in this unlicensed band. Not as restrictive in No. America.

Less so for radios on 868/900MHz. Digi makes these too. Much more expensive.

6

BraneDeadX:
[quote=I have a 2.4GHz wireless camera that I have checked interference with the Rx and it does effect it. So I assume I need to stay away from 2.4GHz modems…Pity since that seems to be where all the action is. I douubt I’m alone in this problem.

Anyone out there running RF modems with 2.4GHz radio control systems? Any recommendations?

I have same problem with a 2.4ghz wireless camera, I just got into using the Xbee Pro wireless radios my self, If someone was worried about interference, why not use just the wireless xbee radio for both your autopilot control and manual control. I know most 2.4ghz and old school FM radios still use PPM (trainer port). It is easy to decode, in which you could piggy back that information on top with anything eles you might be needing to transmit to the airplane. But be ware of any unwanted latency’s…

thats my two cents![/quote]

Analog wireless cameras consume about 6 MHz of bandwidth. The 2.4GHz band internationally is at least 40MHz wide. So, just avoid the area where the camera is.

Netcams (using 802.11) coexist well with 802.15.4 (like XBee, Jennic, et al) because both are listen-before-transmitting packet protocols (CSMA). By design, the spectrum is shared gracefully.