Target BluEye? 2020 thread

Redrum

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I just discovered this project created by @EvanL. It's been almost 4 years since the last update. It doesn't look like Target BlueEye (now owned by www.fourcaraudio.co.uk) is going to make a US version. FYI - from their website, it looks like Europe is working to migrate from TETRA to an LTE-based (i.e., cellular) standard, starting at the earliest in January 2023.

Could newer technology better enable BluePi (EvanL's P25 version of BluEye)? Based on the complexity of P25, I don't see how it can be done for anywhere near $100, which was his original goal. But it still may be worth the effort. I've listed some updated hardware, based on EvanL items (above).

Radio Modules:
The RTL-SDR hasn't really changed since 2016, but one alternative is LimeSDR.

LimeSDR Mini uses the Lime LMS7002M chipset, "... which is a “field-programmable RF IC”: [it's essentially] an RF FPGA analogue."

It costs $187, has a continuous operation spectrum of 100 kHz to 3.8 GHz, has a FPGA, full duplex RX and TX, and can operate up to 120 MHz RF bandwidth.

Available from
1. https://www.mouser.com/ProductDetail/Crowd-Supply/cs-lime-05?qs=qSfuJ%2Bfl/d4XI8aDL9807Q==
2. https://www.crowdsupply.com/lime-micro/limesdr-mini

Frequency Database:
The frequencies to be scanned include systems: P25 Phases 1 and 2, DMR, and NXTL.

Single-Board Computer:
The product he mentioned, ODROID XU4, an 8-core CPU @2GHz with 2GB RAM, now costs $58.

Raspberry Pi 4B isn't up to the job. An updated ODROID w/quad core 2.3 GHz and up to 32GB is available for $135:

Power Supply:
The power requirement is likely the same from what EvanL mentioned - 6-8A @ 5VDC, and would need to talk with the computer. I've seen units with a UPS and this kind of power for about $100. A case is also needed. An aluminum case is offered for the ODROID for $100, which would block a lot of RF, and a plastic version is offered for about $50.

Summary:
The Target BluEye costs about US$1200, and uses a much simpler system than those used in the US. The parts for the device started by EvanL looks like it would run about $600, given various shipping charges, cables, etc. and it could be further developed by the community, once a core product is ready.

Is there interest in something like this?
 

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When a mobile unit using a P25 network keys up, the control channel for its configured network tells the radio what to use: which talk group, frequency, etc.

Question: After that initial handshake, how often does the mobile unit communicate over the control channel? Throughout the "conversation"? Only at the end?
 

GTO_04

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I just discovered this project created by @EvanL. It's been almost 4 years since the last update. It doesn't look like Target BlueEye (now owned by www.fourcaraudio.co.uk) is going to make a US version. FYI - from their website, it looks like Europe is working to migrate from TETRA to an LTE-based (i.e., cellular) standard, starting at the earliest in January 2023.

Could newer technology better enable BluePi (EvanL's P25 version of BluEye)? Based on the complexity of P25, I don't see how it can be done for anywhere near $100, which was his original goal. But it still may be worth the effort. I've listed some updated hardware, based on EvanL items (above).

Radio Modules:
The RTL-SDR hasn't really changed since 2016, but one alternative is LimeSDR.

LimeSDR Mini uses the Lime LMS7002M chipset, "... which is a “field-programmable RF IC”: [it's essentially] an RF FPGA analogue."

It costs $187, has a continuous operation spectrum of 100 kHz to 3.8 GHz, has a FPGA, full duplex RX and TX, and can operate up to 120 MHz RF bandwidth.

Available from
1. https://www.mouser.com/ProductDetail/Crowd-Supply/cs-lime-05?qs=qSfuJ%2Bfl/d4XI8aDL9807Q==
2. https://www.crowdsupply.com/lime-micro/limesdr-mini

Frequency Database:
The frequencies to be scanned include systems: P25 Phases 1 and 2, DMR, and NXTL.

Single-Board Computer:
The product he mentioned, ODROID XU4, an 8-core CPU @2GHz with 2GB RAM, now costs $58.

Raspberry Pi 4B isn't up to the job. An updated ODROID w/quad core 2.3 GHz and up to 32GB is available for $135:

Power Supply:
The power requirement is likely the same from what EvanL mentioned - 6-8A @ 5VDC, and would need to talk with the computer. I've seen units with a UPS and this kind of power for about $100. A case is also needed. An aluminum case is offered for the ODROID for $100, which would block a lot of RF, and a plastic version is offered for about $50.

Summary:
The Target BluEye costs about US$1200, and uses a much simpler system than those used in the US. The parts for the device started by EvanL looks like it would run about $600, given various shipping charges, cables, etc. and it could be further developed by the community, once a core product is ready.

Is there interest in something like this?
I am interested. Given the cost of P25 Phase II Scanners, the cost here seems very reasonable.

GTO_04
 

NoahWL

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I've been slowly putting together a P25 scanner with a few RTL-SDR dongles for my car since I think the functionality and cost of the scanners currently offered is ridiculous. I've thought about scanning for the transmit frequencies, but I'm not sure how well it would work. In the end I think it'd take a lot more development time than I'm willing to put into it.
When a mobile unit using a P25 network keys up, the control channel for its configured network tells the radio what to use: which talk group, frequency, etc.

Question: After that initial handshake, how often does the mobile unit communicate over the control channel? Throughout the "conversation"? Only at the end?
Typically the mobile (subscriber) unit will monitor the control channel unless it is engaged in a call with another unit (transmitting or receiving). If this is the case the radio is tuned to a separate inbound (transmitting) or output (receiving) frequency, known as a traffic channel. The subscriber will not begin monitoring the control channel again until the end of the call.

On some P25 Phase 2 systems, though, a traffic channel can share the same frequency as a control channel by dividing the time spent broadcasting each channel into two different timeslots. This is useful for systems located in heavily congested areas where very few subscriber units will be transmitting at any one time.
 

InsipidMonkey

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I think the hardware side of this is all do-able now (and has been for a few years): RPi, RTL-SDR dongle, antenna, GPS. The ability to decode trunked digital signals (not decrypt, but that is not necessary for this application) and the comprehensive RadioReference database should allow you to configure a system that scans all of the public safety bands in use in your area, and alert you to transmissions on frequencies and/or talkgroups (or even radio IDs) used by police. Even though the RTL-SDR bandwidth is fairly narrow (~2MHz), it can scan quickly and you wouldn't have to dwell in a frequency range very long to tell whether or not there was a transmission. Thus even a single dongle should be able to cover all VHF/UHF frequencies of interest.

The more significant issue, which we've been discussing here https://www.rdforum.org/threads/77668/ , is being able to narrow it down to nearby transmissions. With trunking or repeater systems, just knowing there is traffic on a PD frequency/TG somewhere in the coverage area is not helpful. Instead, you'd want to monitor the repeater input frequencies to detect transmissions from a nearby unit that could potentially be a threat. Unfortunately, as laid out in the above thread, we've had limited success with this. I think it's mostly a problem of the transmitted power of modern radios not being high enough to detect reliably at a useful distance, and also the difficulty in making sure you're actually monitoring the correct input frequencies. If you are able to solve these two issues it should be pretty straightforward to make a working prototype.

It certainly is an interesting idea, and I'm glad there are some new users thinking about it!
 

Redrum

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@InsipidMonkey yeah, that was my take, as well. It looked like @EvanL was making progress, but was stymied by lack of speed in technology (at least for under $100). Have you seen his work? I'm not sure what to make of it. Was he successful? It looks like he made a script that looked for signals seen - but which software was he using to get the signals? Do you have any ideas which software he used?
Post automatically merged:

Does Uniden's Close Call (CC) alert to encrypted transmissions, or does it just skip over them? And can you limit Close Call to specific types of service - like Police, Fire, Ambulance? Does it notify you which type it detected?
 
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NoahWL

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Does Uniden's Close Call (CC) alert to encrypted transmissions, or does it just skip over them? And can you limit Close Call to specific types of service - like Police, Fire, Ambulance? Does it notify you which type it detected?
Close Call will alert to any continuous transmissions that are about 15dB stronger than the frequency's noise floor. So essentially any very strong signal that is present for at least a second. The range for something like a 5W portable is typically only a couple hundred feet.
 

Smason

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Is there a possibility of using a certain SDR based RD to search for this?
 

Redrum

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Some things have been confusing to me. So I'd like help and feedback, to see how far off the mark I am in features we'd like from scanner(s). Please suggest add/remove/modify changes, and let me know your thoughts. *Warning - long post*

Desired Features of Scanner(s)​

I think we're looking for a digital scanner with:
1. A very high bandwidth, and high sensitivity (e.g., 60 MHz, like a LimeSDR), so it can detect all desired local properly modulated transmissions, no matter how short (i.e., 16 ms "pop" type ping; data; voice).

2. It would need to display:
a) signal strength, type of signal (e.g., P25 phase 1; DMR; etc.) frequency, and encrypted status;
b) identifying info: department, TGID, CC, etc.
c) An option to cycle through, say, the top five last strongest signals it's picked up, and send any/all of them to the scanner in item "d", below, to listen to.
d) In the future: direction, using more than one scanner and antenna for DF.

3. Would need a complete set of nationwide frequencies, regularly and easily updated, for desired types of systems (i.e., P25 phase 1 and 2; DMR; NXTL), jurisdictions (e.g., states; counties; cities), and departments (e.g., PD; FD; ambulance);

4. Location: Ability to *only* monitor frequencies within a certain range that are local to your current location (e.g., two miles).

5. *And* an optional second scanner, to listen to configured / sets of frequencies. This scanner can be standard Uniden P25 radio, or a slow RTL-SDR. See my note on Unidens in Hardware, below.


Software​

1. @EvanL BluPi

He ran the linux package "rtl-power-fftw" on a Raspberry Pi to scan a set of frequencies, and collect various info, including signal strength (e.g. RSSI), frequency, etc. He fed the results into his own open source package, BluPi (named after BluEye), to display. My questions about this setup:
a) Can "rtl-power-fftw" detect 16 ms "pop" transmissions?
b) Is demodulation of signals needed to detect what we're looking for (which I'm supposing is "commonly wanted")? If not, what software can do that? Note: the Digital Scout listed above, can detect and demodulate P25 (i.e., FDMA and TDMA), but I'm not sure if it can do that with the "pop" transmissions.

2. OP25​

OP25 has a lot of capabilities, but once it detects a P25 (or DMR, etc) transmission, it *stays* on it, and doesn't continue to listen to the set of configured frequencies, as described above.


Hardware​

1. I think fast SDR's, like LimeSDR, would be a great choice. PlutoSDR is another.

2. Optoelectronics Digital Scout. $500. This scanner can demodulate - but not "listen to" - P25, DMR, etc. transmissions. Once it detects and identifies the type of transmission, it simply logs it, then continues. Can it detect the 16 ms "pop" transmissions?

3. Blue Tail Technologies P25RX. $260. This scanner can demodulate and listen to these transmissions, but it hasn't been programmed with the ability to log then continue scanning.

4. Uniden Scanners: the "optional second scanner" task listed in "Desired Features of Scanners" above, can easily be fulfilled by a Uniden digital P25 phase 1/2 scanner. However, despite its many great features, I don't think those scanners meet the other requirements. Here's why:
a) With Close Call (CC), the signal needs to be at least 15 db above the noise floor. That seems a fair bit less than ideal, right?
b) Close Call can't be set to scan certain frequencies, except to set it for yes/no on any of several large frequency ranges (like 140 MHz to 280 MHz, 280 - 350, etc.). As such, location, services, and systems cannot be configured and have no bearing on which frequencies it scans.
c) When it detects a transmission (i.e., on a programmed frequency, not with Close Call), it will always stop and stay tuned to the broadcast. This can be helpful when listening for certain types of events. But I'm thinking that the primary use of a P25 scanner would be like the Close Call - only *without* the 15 db noise floor, and *with* the ability to configure which frequencies it scans (depending on location).
 

Serot

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Hi, sorry to break in :) But isn't the SDR Power Monitor app, present in the Google Playstore, a basic version of what you are looking for?

I'm using it as alternative for the the (in my opinion) way too expensive Target Blue Eye. The SDR Power Monitor app is capable of monitoring signal strengths on configurable frequencies using one or more SDR devices. It will alert you in case a threshold is reached. In my case I'm alerted in case traffic police cars are nearby..

The the usage by another happy user:
 

Redrum

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Hi @Serot! That looks like an interesting program. Can you set it to monitor/scan through thousands of frequencies? TETRA uses only a couple.
 

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Xenoo

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This would be super cool if it was able to be done.
 

Monus Brewer

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So the question for me this, is it able to decode the correct frequency of control channel data to determine what freq pair to use. Is anything capable to decode the audio from P25 (I &II) and the other encryption types? I am just wondering, I use to have a Uniden but pretty much hated it, the pd cars were open and the pd dispatch was encryption on P25. The FD and ambulance service is also open so no issues with them.

Tennessee Highway Patrol uses open stuff but have a encryption channel when then are doing tactical responses....

Just wondering. 😁
 

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