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ADS-B data into Skydemon with a Raspberry Pi


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schweboo
schweboo
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I have consulted those who understand this stuff and quote:

"Virtually all receivers employ what is know as the "superheterodyne" (superhet) design. The incoming signal is mixed with a very low power locally created signal to produce an intermediate frequency where most of the signal amplification takes place. This locally created signal is known as the "local oscillator" and it is, in effect, an extremely low power transmitter.

Dongles like the one we use actually convert down to baseband where digital signal processing (DSP) is used to render the required signals. The superhet concept still applies, so in theory, at least, it is possible for interference from the local oscillator to occur. It is, however, an extremely improbable effect. It would only occur in the event of a fairly significant malfunction in the dongle's electronics, as the local oscillator should not be tuned to anywhere near any of the frequencies that we use. I don't discount it by any means but there are other places I'd be looking first".
Edited 2/3/2016 1:02:14 PM by schweboo
nkriek
nkriek
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schweboo - 2/1/2016 7:31:51 PM
Quite a few pilots have been testing this 'home-made' device successfully.

My experience has been positive, with the RPI linked to my GPS running Sky Demon on an IPAD mini (without a GPS chip) with no adverse impact on the aircraft's Garmin 430 GPS system or the GPS in my Iphone (with its own GPS chip) also running Sky Demon). With three different GPS systems running, I have been able to compare one with the other and have noticed no differences in performance. The position I have been getting from all three GPS devices has matched my ADF and what I could see with my eyes. The advance warning of an aircraft heading towards me that I got from the RPI device was astounding. I first saw the aircraft on Sky Demon at a range of around 8nm. I was able to actually see the aircraft when it less than half a mile away and it was at the relative altitude reported by Sky Demon (1400 ft above me). Had I not known where to look, I would not have seen the aircraft as early as I did.

I have also tried running my Ipad with the RPI device operational at home for hours without any interference. I have experimented using both a Dual GPS and a GPS dongle USB device plugged into the RPI. Both worked equally well with SkyDemon.

I had had some initial connectivity problems, but these were caused by me not following the Pilot AWARE instructions to the letter. Since realising the error of my ways, I have had no RPI (Pilot Aware)/Sky Demon connectivity problems.



nkriek
nkriek
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schweboo - 2/3/2016 1:00:56 PM
I have consulted those who understand this stuff and quote:

"Virtually all receivers employ what is know as the "superheterodyne" (superhet) design. The incoming signal is mixed with a very low power locally created signal to produce an intermediate frequency where most of the signal amplification takes place. This locally created signal is known as the "local oscillator" and it is, in effect, an extremely low power transmitter.

Dongles like the one we use actually convert down to baseband where digital signal processing (DSP) is used to render the required signals. The superhet concept still applies, so in theory, at least, it is possible for interference from the local oscillator to occur. It is, however, an extremely improbable effect. It would only occur in the event of a fairly significant malfunction in the dongle's electronics, as the local oscillator should not be tuned to anywhere near any of the frequencies that we use. I don't discount it by any means but there are other places I'd be looking first".

I have bought the components and want to build the PilotAware unit. My iPad does not have the GPS chip and I use the Dual150 (GPS and Glasnoss) connected via Bluetooth to the iPad. Would you recommend routing the Dual system via the PilotAware or the iPad? Any tips, information etc you can send me to assist in the building of the unit will be much appreciated.
Neels

George Reid
George Reid
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nkriek - 10/1/2016 12:08:21 PM
schweboo - 2/3/2016 1:00:56 PM
I have consulted those who understand this stuff and quote:

"Virtually all receivers employ what is know as the "superheterodyne" (superhet) design. The incoming signal is mixed with a very low power locally created signal to produce an intermediate frequency where most of the signal amplification takes place. This locally created signal is known as the "local oscillator" and it is, in effect, an extremely low power transmitter.

Dongles like the one we use actually convert down to baseband where digital signal processing (DSP) is used to render the required signals. The superhet concept still applies, so in theory, at least, it is possible for interference from the local oscillator to occur. It is, however, an extremely improbable effect. It would only occur in the event of a fairly significant malfunction in the dongle's electronics, as the local oscillator should not be tuned to anywhere near any of the frequencies that we use. I don't discount it by any means but there are other places I'd be looking first".

I have bought the components and want to build the PilotAware unit. My iPad does not have the GPS chip and I use the Dual150 (GPS and Glasnoss) connected via Bluetooth to the iPad. Would you recommend routing the Dual system via the PilotAware or the iPad? Any tips, information etc you can send me to assist in the building of the unit will be much appreciated.
Neels

As far as I am aware, the latest implementation of PilotAware employs a GPS dongle in one of the Raspberry Pi USB Ports.  When Running PilotAware with Sky Demon you need to tell Sky Demon to connect to FLARM. Then PilotAware supplies the GPS fix to Sky Demon and the Dual150 GPS device is not used.  However if the PilotAware device was to fail or Hang up you would then need to instruct SkyDemon to take its GPS input from the Dual150.



George E A Reid

Ipad Mini 2,  IOS 12.4,  SD 3.12.8.190
PC(Win 10, Version 1809)  SD 3.12.8
PilotAware 20190621
Edited 10/1/2016 12:29:09 PM by GEAR
nkriek
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GEAR - 10/1/2016 12:28:22 PM
nkriek - 10/1/2016 12:08:21 PM
schweboo - 2/3/2016 1:00:56 PM
I have consulted those who understand this stuff and quote:

"Virtually all receivers employ what is know as the "superheterodyne" (superhet) design. The incoming signal is mixed with a very low power locally created signal to produce an intermediate frequency where most of the signal amplification takes place. This locally created signal is known as the "local oscillator" and it is, in effect, an extremely low power transmitter.

Dongles like the one we use actually convert down to baseband where digital signal processing (DSP) is used to render the required signals. The superhet concept still applies, so in theory, at least, it is possible for interference from the local oscillator to occur. It is, however, an extremely improbable effect. It would only occur in the event of a fairly significant malfunction in the dongle's electronics, as the local oscillator should not be tuned to anywhere near any of the frequencies that we use. I don't discount it by any means but there are other places I'd be looking first".

I have bought the components and want to build the PilotAware unit. My iPad does not have the GPS chip and I use the Dual150 (GPS and Glasnoss) connected via Bluetooth to the iPad. Would you recommend routing the Dual system via the PilotAware or the iPad? Any tips, information etc you can send me to assist in the building of the unit will be much appreciated.
Neels

As far as I am aware, the latest implementation of PilotAware employs a GPS dongle in one of the Raspberry Pi USB Ports.  When Running PilotAware with Sky Demon you need to tell Sky Demon to connect to FLARM. Then PilotAware supplies the GPS fix to Sky Demon and the Dual150 GPS device is not used.  However if the PilotAware device was to fail or Hang up you would then need to instruct SkyDemon to take its GPS input from the Dual150.


Thank you George

GO

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