BTT: Open-source projects.

[btt]

This thread will be dedicated to open source projects related to Bluetail Technologies and the personal projects that lead to its creation (not previously mentioned here on RR). I am very grateful to the RR community that has been supportive of the P25RX and P25RX-II receivers and the development of the related software and firmware. It wouldn't have been possible to develop while paying the monthly bills without you guys. I sincerely believe that if it weren't for our incompetent leaders and the supply chain disruptions of the past couple of years, that Bluetail Technologies might have been able to expand and grow to more than just myself scrambling to figure out how to stay ahead of the consecutive disasters. I've been honest with you guys in the past about everything and it is time for another update. I currently have enough parts to build 13 more units (I'm holding back parts for 2 units for whatever reasons). As you know, I went into debt buying parts to try and stay ahead of the "parts shortage". The sales were reinvested back into more parts purchases and paying the bills to keep the house, and to feed myself and the dog. It is clear to me now that things will probably never get back to "normal". The "Chips Bill" being considered right now will not fix the issues. Intel will never be able compete with TSMC. In addition to that, both TSMC and Intel have made it clear that they have no interest in producing traditional automotive MCU parts like the ones utilized by the P25RX/P25RX-II ( 40nm process). Granted, the MCU in the P25RX is a very high-end MCU, but why do we need an 8-core CPU with a heat sink and fan to control anti-lock brake systems? It makes about as much sense as anything else coming out of DC these days. As it is right now, the only place I have been able to locate more MCU parts is no-name distributors in China that purchased the parts in large quantities and are now selling them for 10x more. The MCU I paid $12 for a couple of years ago is now selling in the range of $100 or more. It may not have made a difference anyway. Sales have plumeted this past month.

I know many of you probably saw my meltdown after too many drinks the other day. I really feel bad about doing that after all the support so many of you have shown me. I apologize. I really let you guys down. I've never been a marketing or public-facing person in my life until BTT, and so I suspected I might do something stupid sooner or later. There are parts for 13 more receivers if you still want one. I will continue to develop firmware and software for the P25RX and P25RX-II. It will likely be slower than usual progress as I find other ways to keep the house and bills paid.

I hope you don't mind if I provide a bit of background in this post. If you are thinking that I was fired from my previous job before starting BTT, you would be wrong (although I would understand if you thought that). They gave me weeks of time off to reconsider my resignation. Over the 6 year period I worked there, I redesigned their entire product line from the ground up. In that period I was able to design and successfully get 12 new products though FCC certification with variations on frequencies of 150-170 MHz, 450-470 MHz, 902-928 MHz (only unit available with flat gain, max power and 72 Mbps), 2.4 GHz band (high power, up to 300 Mbps), 4.96 GHz federal (probably highest power available anywhere providing hi-res video over 10 miles links), 5.8 GHz band, a 30 Watt VHF amp, and a 70 MHz - 6 GHz real-time field spectrum analyzer. After some weeks of reconsideration, I decided to leave. I left them in good shape. Everything was in production and all the engineering design reference documents were written for the next guy. I felt very good about how I left. Within a couple of months of leaving that job, I saw in local news that the main person I worked with was arrested by a swat team for allegedly molesting his kid. They kept him on after that. I've never desired to go back since that. After a few drinks, I do kick myself sometimes when I think about how I could be taking it easy now and collecting the big paychecks for all that hard work. I don't think they have designed any new products since then. I'm not putting this out there as an excuse for my recent bad behavior. I'm only trying to provide some context for why I have the occasional meltdown. I really loved that job. I gave it my all day and night. If only they would have allowed me to work remotely and away from them, I would have stayed.

As promised, I will be open-sourcing the P25RX and P25RX-II designs. It will take me some time to get everything ready for that. I will continue to work on these products even after they are open-sourced. After my recent public meltdown, I doubt there will be many interesting employment options in my future. After I left the previous job, I immediately started working on SDR projects. I've already open-sourced some projects and I will list them here to get this thread started.

Project Charon

GitHub - tvelliott/charon: Enable your Pluto SDR to become a stand-alone OFDM transceiver with batman-adv mesh network routing capabilities

Enable your Pluto SDR to become a stand-alone OFDM transceiver with batman-adv mesh network routing capabilities - tvelliott/charon

github.com

Project Charon was the first thing I worked on after leaving the previous job. I believe it is the first example of an open-source SDR transceiver capable of OFDM, 64-QAM with 64 sub-carriers. All in a 144 kHz channel! The implementation includes a MAC layer that is similar to 802.11 in that it provides retries and allows IP communications over wireless. It also supports Batman Advanced mesh networking. I had 4 nodes for testing the mesh networking. It works great. The mesh networking with Batman is at the MAC-level layers and it is transparent to everything above that. I haven't looked back at this since I released it a couple of years ago, but I'm very happy with how it turned out. I think there are some ham radio operators using it in the 12cm, but I haven't heard from them personally. All of the code is available in the github repository.

Project SuperH V4
GitHub - tvelliott/superH_rev4: Ultra performance narrow-band receiver. Most of the important parts are fabbed in the US. The superH is a 480MHz STM32H743 based SDR capable of decoding advanced protocols such as P25 without a host PC.

superH_rev4/superH_rev4_release_schematic.pdf at master · tvelliott/superH_rev4

Ultra performance narrow-band receiver. Most of the important parts are fabbed in the US. The superH is a 480MHz STM32H743 based SDR capable of decoding advanced protocols such as P25 without a h...

github.com

This project was my attempt to create a stand-alone SDR with high-level performance. I didn't worry about cost on this project. This is the kind of thing that you should only do if you have lots of money (I don't). I used many parts that are actually fabbed here in Washington state. Of course, most of the parts are no longer available after the Covid lockdown disaster. I haven't released the firmware for this project yet. I will be releasing it at a future date.

There are more repositories to create and upload. I have a couple of designs with FPGAs including another SDR based on the AT86RF215. This design was the precursor to the P25RX design. To be continued..

 

[freqseeker]

Todd I want to thank you again for all the hard work. I have two receivers and they work great for me.
I look forward to further progress but fully understand the income issue.
You are very talented and will be sucessful in anything you do.
I enjoy the conversations while testing new firmware. If there is anything I can help you with please contact me.
As you know my father has been in hospice with cancer and alzheimers. He is down to his final days and I care for him at home. This is why I haven't been active here, but my rx's continue to entertain me.

 

[btt]

@freqseeker, thank you. I hope you and your father's last days are as good as they can possibly be my friend.

 

[btt]

I created a repository for the AT86RF215-based SDR. This design is from 2018. It is capable of stand-alone reception of P25. The implementation does not include trunking. I didn't start working on trunking code until the superH_rev4 receiver. The FPGA is a 256-pin BGA, ICE40 8k. The AT86RF215 supports a DDR (dual-data-rate) I/Q interface with 12-bit ADCs. The FPGA is connected to the MCU external bus and memory-mapped. It supports DMA for the transfers. The firmware supports monitoring with GQRX via a modified version of the RTL-TCP driver (in order to support 16-bits).

GitHub - tvelliott/SDR_at86rf215: SDR design based on the AT86RF215 transceiver with IQ LVDS / FPGA DDR (dual-data-rate) interface

SDR design based on the AT86RF215 transceiver with IQ LVDS / FPGA DDR (dual-data-rate) interface - tvelliott/SDR_at86rf215

github.com

 

[pcman67]

@btt , I am sorry to hear about the current parts situation and I suspect the sales of the P25RX series dropping off might be due to increased prices everyone is experiencing due to high inflation that are squeezing a lot of people financially.

Regardless, I think you are a super talented individual that has created a receiver that is in a class of its own and for what it does, it betters some of the devices out there that cost more from major manufactures/corporations.

I’ve always thought to myself that if I was a rich investor, I’d probably make you an offer to acquire BlueTail Technologies and/or bring you on as a chief product engineer/designer, but alas I’m just an average working class individual.

Instead of open sourcing your P25RX product line, have you ever thought of selling your product line to a major manufacturer like Uniden, for example, to see if there is any interest?

Regardless, you need to do what you need to do to pay the bills, keep the house, etc. and I wish you the best outcome possible, whatever that may be. I’m a firm supporter of your product and I’m honored to have collaborated with such a talented individual like yourself on trying to make the P25RX line as good as it can be.

Jim

 

[btt]

@pcman67, Jim,
Thank you. I appreciate all the many hours of testing, help, and friendship over the past couple of years. I also thank you for the Mac Airbook and Win 10 laptop for testing! I'm sure quite a few others here thank you for that as well. It makes getting things working on multiple platforms much easier. Regarding selling Bluetail Technologies, I don't think the big companies would be interested at this level. I'll sell it to you really cheap! : ) I will continue to work on these projects regardless of how things proceed.

 

[btt]

I forgot that there was a separate VHF/UHF tuner board with a frequency synth, high-level mixer, auto-switch between UHF/VHF antenna connectors depending on tuned frequency. The AT86RF215 board controls the tuner board. and converts everything to a 900 MHz IF. The IF is filtered through a ceramic mono-block / inter-digital type filter. I added the eagle design files and firmware for that assembly to the repository as well.

 

[Mophead]

Hi Todd, I don't post much but I do read this sub forum almost everyday. I didn't see your meltdown but I sure do hope your situation improves. Your receiver is top notch and your help on this board everyday is almost unheard of today. Any big tech company involved in your specialties would be a FOOL not to hire you on the spot! Thank you for the excellent receiver and all the help and advice you give us all.

 

[btt]

Hi Todd, I don't post much but I do read this sub forum almost everyday. I didn't see your meltdown but I sure do hope your situation improves. Your receiver is top notch and your help on this board everyday is almost unheard of today. Any big tech company involved in your specialties would be a FOOL not to hire you on the spot! Thank you for the excellent receiver and all the help and advice you give us all.

@Mophead, Thank you!

------
SDR_AT86RF215 repository update: I made some changes to the eagle design files and schematic to reflect changes that were made to the front-end of the receiver. This was done after the separate tuner board was introduced and the IF frequency was changed to 900 MHz. Note that the dual-data-rate IQ interface is fully functional, so the receiver can actually be used as an SDR transmitter (without the tuner / down-converter attached).

GitHub - tvelliott/SDR_at86rf215: SDR design based on the AT86RF215 transceiver with IQ LVDS / FPGA DDR (dual-data-rate) interface

SDR design based on the AT86RF215 transceiver with IQ LVDS / FPGA DDR (dual-data-rate) interface - tvelliott/SDR_at86rf215

github.com

 

[epersson]

@btt I didn't see your meltdown either, but fully understand what a job can do to you... even when you love it you can burn out... especially high performing, its the dregs that last forever in the broom closet... I hope you're doing OK.

As part of my job, and not wanting to get into a convoluted discussion about politics, I have been talking to friends all over the world and this economic issue, as much as many want to make it a domestic political thing, is a global event. It's impacting everyone.

 

[FreqNout]

Todd, Thanks for having the guts to leave your job and build your designs to allow us to enjoy your excellent products. Few reading this forum would have the balls to quit and risk going broke to pursue a dream.

The real bad news is the lack of parts in the supply chain to build more P25RX models. In my line of work, cellular network engineer, we now have to shuttle radios between cell sites due to lack of parts to keep the network running.

I will continue to develop firmware and software for the P25RX and P25RX-II. It will likely be slower than usual

The above statement IS the GOOD news.

Open sourcing the circuit design will help those that may need to troubleshoot a component failure or even mod the circuit if other parts become available.

The current Stable Firmware allows everyone’s P25RX/RXII to continue running. @btt your continued support of the firmware - even at slower rate - will keep your dream alive.

 

[btt]

Firmware has been added to the superH_rev4 repository. This design is from 2019. Rev 5 was going to add a 10 MHz reference clock option for GPSDO. I designed a small board for the glitchless clock switchover and tested it. The rev4 firmware, as-is, expects a 10 MHz reference to feed the synths and the MCU. I will add a repository for the 10 MHz ref clock switch later, but I see that part is out of stock as well.

GitHub - tvelliott/superH_rev4: High performance narrow-band receiver. Most of the important parts are fabbed in the US. The superH is a 480MHz STM32H743 based SDR capable of decoding advanced protocols such as P25 without a host PC.

High performance narrow-band receiver. Most of the important parts are fabbed in the US. The superH is a 480MHz STM32H743 based SDR capable of decoding advanced protocols such as P25 without a ho...

github.com

 

[turnpike61]

Todd: The P25RX is a fantastic device, with superb and clever engineering, and your post gives me more insight into the person behind it. You have a bright future ahead, and do not let a single moment of temper cause you to devalue yourself. You have a great deal of technical talent, and are a very good customer facing owner, despite the inexperience. I sure wish my flameups were as mild as what you apologized for! Night.

 

[kb8q]

I started monitoring in the 60's (before scanners) with a tunable VHF receiver. The analog days have gone the way of the dinosaur. The P25RX is on the leading edge of the new technology.

In my 60 years of monitoring, I have never had any product with the versatility and capability of the P25RX products. Michigan has one of the largest state operated public safety communications systems in the US with 100,000 users, 80,000 radios and several hundred sites. In SE Michigan, I'm, using 3 P25RX-II receivers to track over 3,000 talk groups on 2 different simulcast systems on the larger network plus one small standalone site.

I also have several Unication G5's plus multiple TRX-1 radios. Nothing compares with the P25RX in terms of programming, operational customization and data collection.

Todd's support has been phenomenal. How one person an ongoing basis can deliver a small receiver and the associated software along with support over time is beyond me. Large companies don't do what Todd has been managing to do by himself.

If I were to pick one thing which might allow for customer base expansion and growth it would be an updated manual. There's a learning curve to effectively use the P25RX which a good manual might leave some time for Todd to do what he does best. I often wonder how much time would be saved if there was an up to date reference to support all those questions we all have individually. That's a mountain to climb for a single person building the receivers, fine tuning and improving the software, providing technical support and everything else that goes into this.

Hats off and many thanks to Todd for everything he's produced with this excellent P25 product.

James

 

[scannerboy02]

I echo what a lot of others have said. I unfortunately have not had as much time as I want to really put the devices to full use but for what I have done with them so far nothing compares.

If I were rich I also believe in this product to the extent that I would also make an investment offer to help financially support this business.

This brings me to an idea, Todd would you be willing to consider some kind of crowd funding? I would definitely be willing to put a little money towards keeping this going in that manner? It sounds like the bigger issue is parts availability, would crowd funding help with that in any way?

I wish I had the funding to take the remainder of your inventory off your hands right now because my eventual plan for my office setup uses 10 of these devices to replace the 13 scanners I'm currently using.

 

[dcr_inc]

The crowd funding sounds like a very viable option to help offset Todds expenses.. The support he has given ALL OF US is not cheap.. He spends MANY of his waking hours, working on things WE want from the P25's.. If someone can get crowd funding started, I will definitely donate to it.. The P25RX sales shouldn't be his only reward.

Lets support the guy who keeps on giving !!!
Dave

 

[btt]

Wow. You guys continue to amaze me with your generosity and kindness. I really appreciate all the comments.

This brings me to an idea, Todd would you be willing to consider some kind of crowd funding? I would definitely be willing to put a little money towards keeping this going in that manner? It sounds like the bigger issue is parts availability, would crowd funding help with that in any way?

Yes, I would consider crowd funding for some kind of physical deliverables. I will explore what options may be out there. So far, the pricing that I found from Chinese vendors is very high compared to pricing here in the US. I assume the auto manufacturers must be paying that much for these hard to get parts and driving the price up? I also have an idea for a higher-end receiver with parts that are available as of today (could change tomorrow). I don't think it would fit inside the current enclosure. I'm planning on starting to work on a prototype during off hours. I'll share more about this later depending on how it goes. I would like to say more about it, but I'm afraid if I start getting specific, those parts will disappear too.

Regarding the MCUs needed for the P25RX/P25RX-II:
P25RX needs stm32h743zit6 (TQFP-144, 480 MHz 'V' version)
P25RX-II needs stm32h743vih6 (BGA-100, 480 MHz)

 

[scannerboy02]

Yes, I would consider crowd funding for some kind of physical deliverables. I will explore what options may be out there.

Sounds great! Please let us know what works best for you.

I also have an idea for a higher-end receiver with parts that are available as of today (could change tomorrow). I don't think it would fit inside the current enclosure. I'm planning on starting to work on a prototype during off hours. I'll share more about this later depending on how it goes. I would like to say more about it, but I'm afraid if I start getting specific, those parts will disappear too.

Not that I want to tell you what to do, but I also have some ideas for a product that I would love to see on the market but am not smart enough to manufacture myself, I have little doubt that you would be able to do it though.

btw, 3 people have ordered the P25RX-II since this thread started. Thank you! There are parts for 10 more if I hold out 2 for repair / replacements.

I just picked up two more units (unfortunately all I can afford at this time) but I wanted to do what I can to help things along.

 

[btt]

Sounds great! Please let us know what works best for you.


Not that I want to tell you what to do, but I also have some ideas for a product that I would love to see on the market but am not smart enough to manufacture myself, I have little doubt that you would be able to do it though.


I just picked up two more units (unfortunately all I can afford at this time) but I wanted to do what I can to help things along.

Thank you!! Please let me know about your product idea. You can post in a thread or email directly. Whatever you prefer. I am very interested in product ideas right now.

 

[scannerboy02]

Thank you!! Please let me know about your product idea. You can post in a thread or email directly. Whatever you prefer. I am very interested in product ideas right now.

You're very welcome.

I will get it typed up tonight and email it to you.