APRS new device hardware project discussion

[kg6qgf]

Let me start this by saying; If this is re-inventing the wheel, let me know ASAP before I spend bunch of time on it! If this is bad idea, same!

My idea is to make an open source design and easily available parts to build a 2 meter data concentric device for APRS use primarily, Packet radio (BBS) secondarily, other uses as requested. I would like to start by sharing what I have been thinking and see if it get any traction before I spend any time and work on it for real.

VERY HIGH LEVEL; CHEAP, CHEAP, K.I.S.S. (sub $100?)

Make a hand held 2 way radio that resembles a smartphone in size and shape, BUT IS NOT! It would be a VHF (2 meter) 2-way radio that will do voice operation via a remote mic with 2.5mm/3.5mm audio jack set supporting common and cheap remote mics. Primarily however, it is a data device with modem designed to operate on 144.390MHZ and will lend itself to building out the APRS network corner cases and be an experimental platform that one holds in their hand. It will do tracking, mapping drawing, digipeating as users expect for APRS,

I am HOPING it could also do packet decoding and display, text messaging, short email over the air from Ham to Ham; Utilize Igates and hopefully be able to "poll" for any traffic directed to its callsign, and handle any broadcast messages, weather alerts, etc. Ideally, it could do some of these activities in an automated way, in the background when device is hibernating. I say "hoping" as I am NOT a software engineer, at the very best I am a terrible software code writer. I would need help from community to have any chance of starting this. I hope that smart digipeating or smart packet handling might be able to help improve current network traffic;

To start, I would use the STM32F407 since it seems to have traction in the mcHF developers community, and might be able to leverage some of their work. Add on ample RAM and Flash;

It would have a CMX614 modem (bell 202), 1200/2200 baud modem unless it is felt that narrow band could support faster (or if it is felt the STM32 DSP could handle modem activities in background); GPS with integrated antenna; 160x160 res 4.2" display with resistive touch panel, Lipo ~2000mAh battery, Dorji DRA818V radio module, Vib motor and piezo devices for notification. It would have docking station for charging and flashing code to Microprocessor. It might even have Bluetooth BLE radio if need were there. The goal would be for unit to last 24 hours + on single charge;

Initially I would draw up schems, create Gerbers, build PCBs and build a hand full of devices to send to software co-conspirators; I would in parallel document the entire process so others could duplicate exactly what I was doing.

This effort however would hinge ENTIRELY on support and commitment from Ham software developers wanting to write and port software, and general interest from community. It would also be a spare time/hobby effort as work must always take front seat.

Your input, comments and criticism is welcome and invited.

 

[AK9R]

Be careful about re-inventing the wheel. Also, be aware that you may spend a lot of time and effort for very little return. The APRS and packet radio markets are very small.

Argent Data and Byonics have fairly full-featured APRS and packet TNCs with add-on display capabilities. There are also APRS-oriented TNCs from Coastal Chipworks, Big Red Bee, and others. Coastal Chipworks has an add-on TNC that adapts to a Raspberry Pi thus the Pi provides the computing power.

Google "HamHUD". This was a project for an APRS TNC with display and simple UI mounted in a small box that could be mounted on the top of your dashboard (hence, "HUD"). The project floundered after the developers started becoming concerned about state and local laws regarding driver distraction. There's also the air bag issue to consider. A Canadian ham also started developing similar device, but it died due to lack of interest, I guess.

Most of the inexpensive APRS TNCs are doing the packet decoding in software rather than the expense and chip count impact of using a standalone modem chip.

 

[K5MPH]

Has this not been done already (Kenwood D-72a)Handheld radio......

 

[AK9R]

Has this not been done already (Kenwood D-72a)Handheld radio......

But, not for less than $100.

 

[eorange]

There is no reason not to build it and experiment, and your open source efforts would be appreciated (and no doubt spawn similar efforts not related to APRS).

But if I were you...I wouldn't expect widespread adoption, and I'd forget about any price point. APRS is about as mature as it's going to get, so only the diehard makers would probably follow your lead.

Unless you're itching to start with a bare board...I'd start by prototyping your ideas and testing feasibility with a Raspberry Pi, or better yet an Arduino if you want to prototype the discrete component route.

Good luck!

 

[kg6qgf]

Thanks for feedback; The thing that most of these devices have in common are 3 items; 1; they are tracking and position reporting concentric. This means the focus on the ability of device to report its position. 2; they need you to pair with a host smartphone or PC to utilize packet decoding or txt messaging. 3; they are not open source dev platform, rather a specific vendors idea of what should happen. These "solutions" seem to be mostly a clunky appliance "add on to your handheld" or "pair with your smartphone" or "use our proprietary software" or a two way voice radio that sort of does data-in need of host device to operate (like android or pc) and dont seem to notify user of incoming message unless user is attached and watching, or cache anything local, nor do off line activity.

The APRS-IS email in interesting, but seems like only 1-way delivery. I can send, but not receive.

I think what I am most disappointed in is that a surprising number of Hams think APRS stands for Automatic Position Reporting System or in some way think the only use for this is tracking or reporting position. In reality APRS is really a potentially robust Mesh network and has the potential to do so much more. If you forget the concept of position reporting and ask yourself "what else can I do with this network" the ideas start pouring in. That combined with the fact that lots of digipeaters are in existence and Igates that connect (in theory, 2-way delivery) the internet to this wireless mesh network...Then ask yourself "what would the appropriate all-in-one device look like to fully utilize this architecture? "...Not "gee, what accessory needs to attach to what accessory to read packets and try to decode...and...and...so-on".


Just want to emphasize I do not want or need to make any money of this; Just a hobby like most of you. In fact, I will am willing to donate my time, expertise and some of my own money to build this out, but NOT without any interest (or help) from others.

If there is no interest, this dies here. I will also contact the Tuscon Amateur Packet Radio APRS SIG, great suggestion.

 

[vagrant]

My idea is to make an open source design and easily available parts to build a 2 meter data concentric device for APRS use primarily, Packet radio (BBS) secondarily, other uses as requested.

I would like to use something like this, but it appears to be impractical due to the power output typically needed and the antenna half of the system. The Kenwood D74A with its Bluetooth capabilities could keep things wireless.

As suggested, a Raspberry Pi could be used as a start and or a phone application. While I use Apple products, they are not that friendly with Bluetooth interfacing. Alternatively, Android devices and rooted Kindles could probably get in on the fun too.

Again, the biggest obstacle would seem to be the the radio aspect of this and the power and antenna requirement for 2m. I have a RX only IGate to help things get through to the Internet, but tower saturation is key for cellular network radios that use low power. I would think there would be RF safety issues as well depending on the power output to reach digipeaters and or IGates.

I would purchase an app that would easily allow me to TX/RX email/messages via RF APRS. If it connected via Bluetooth to the D74A it would be ideal. If it needs to be wired up, I already have those solutions. The thing is, my cellular phone service handles duties like this now. If there is an issue with Internet connectivity or cellular outage, I would not really be put out to connect a tablet PC to my D74 and open up APRSIS or Winlink express or even just go back to using old T9 to send a message. Basically, I would only use this when cellular service is not available. For me, that does happen when I am camping in the Sierra Nevada mountain range.

I could swear I have sent and received email via APRS. Perhaps I am confusing it with Winlink. Have you heard or read about Winlink? https://www.winlink.org/ It works well. I have VHF/UHF stations nearby. HF works well too.

 

[kg6qgf]

There is no reason not to build it and experiment, and your open source efforts would be appreciated (and no doubt spawn similar efforts not related to APRS).

But if I were you...I wouldn't expect widespread adoption, and I'd forget about any price point. APRS is about as mature as it's going to get, so only the diehard makers would probably follow your lead.

Unless you're itching to start with a bare board...I'd start by prototyping your ideas and testing feasibility with a Raspberry Pi, or better yet an Arduino if you want to prototype the discrete component route.

Good luck!

I have experimented years ago on some of this, I also have a ton of experience in Smartphone product design. As such, there would be little difference in building parts and connecting them up for proof of concept or software dev, rather I would build as close to final hardware as possible right up front.

Here is a little story I would like to share; There used to be a company here in Bay Area called Tadpole Computing. They built a ruggedized laptop computer used in field by technicians that could be beat up and tormented. What most people do not know is how they did their designs; Since the computer was never expected to be small or sleek or even nice looking, they would go to Tier One computer manufacturer and buy an older model laptop design from them; complete with injection molds, keyboard, housing, battery cases and chargers, etc and build a new motherboard with updated parts to fit in this old housing. In that fashion they kept their costs on mechanical engineering very low. My plan is to do the same; I have my eye on a product that I can use as a template for this design, is readily available on used market and very cheap. Make a new motherboard for it and presto, device.

In other words, minimize my design efforts and cost....and speed up my time of development.

 

[kg6qgf]

I would like to use something like this, but it appears to be impractical due to the power output typically needed and the antenna half of the system. The Kenwood D74A with its Bluetooth capabilities could keep things wireless.

As suggested, a Raspberry Pi could be used as a start and or a phone application. While I use Apple products, they are not that friendly with Bluetooth interfacing. Alternatively, Android devices and rooted Kindles could probably get in on the fun too.

Again, the biggest obstacle would seem to be the the radio aspect of this and the power and antenna requirement for 2m. I have a RX only IGate to help things get through to the Internet, but tower saturation is key for cellular network radios that use low power. I would think there would be RF safety issues as well depending on the power output to reach digipeaters and or IGates.

I would purchase an app that would easily allow me to TX/RX email/messages via RF APRS. If it connected via Bluetooth to the D74A it would be ideal. If it needs to be wired up, I already have those solutions. The thing is, my cellular phone service handles duties like this now.
.

I agree on the Kenwood BT link and phone app EXCEPT for 2 things; 1. that ideally I would like to instruct the radio to perform task in background and sever the link. When I re-link in, my email, group messages, CQ calls and text are waiting for me as they were retrieved in background. 2. Notify me that a new message was retrieved and waiting for me to read, just like your smartphone and PC do today.

One of the things I learned from marketing people about accessories was that only a small fraction of users like to attach accessories, regardless of the accessory (called the attachment rate). Users were much more likely to use feature if it was built into the device. There are exceptions, but not a lot.

The tower saturation in theory is solved by digipeaters, I.E. mesh network. I have been told that most people only need 0.25 watts on APRS beacon devices, that 5 watts is way overkill. Your smartphone when on 900mhz (TDMA) is putting out up to 33dBm, or 2 watts, My guess is our radios at 150mHZ is far less dangerous than 900mhz. I would say builder beware, be informed, reduce duty cycle. Maybe add an accelerometer and gyro and reduce power output and duty cycle when not in use.

What app do you get today that does text, email and messages EASILY now? Also, background operation...Even my old packet radio modem in BBS days had an email box built in and other hams could leave me messages to my call sign-where did that go?

 

[kg6qgf]

One more thing I wanted to add here; Take from Bob's APRS website; http://aprs.org/

"
THE GOAL IS COMMUNICATIONS and LOCAL INFO UPDATE, -NOT- JUST VEHICLE TRACKING!

APRS was never intended to be just a vehicle tracking system (GPS was added in the 1992 time frame when GPS became affordable).
"


"APRS is not a vehicle tracking system. It is a two-way tactical real-time digital communications system between all assets in a network sharing information about everything going on in the local area. On ham radio, this means if something is happening now, or there is information that could be valuable to you, then it should show up on your APRS radio in your mobile. "

 

[AK9R]

I will also contact the Tuscon Amateur Packet Radio APRS SIG, great suggestion.

Just be aware that some of the guys in the TAPR APRS-SIG have been involved with APRS since Day One. They treat new people and new ideas with a large dose of skepticism. Ask respectful, intelligent questions and you'll get detailed, intelligent answers. Act like you know everything already or express plans to "save" or "re-invent" APRS and they'll hand you your hat.

 

[K5MPH]

Just be aware that some of the guys in the TAPR APRS-SIG have been involved with APRS since Day One. They treat new people and new ideas with a large dose of skepticism. Ask respectful, intelligent questions and you'll get detailed, intelligent answers. Act like you know everything already or express plans to "save" or "re-invent" APRS and they'll hand you your hat.

Yeah I agree,these were the guys that develop the Terminal Node Controller (TNC).....

 

[K4APR]

Let me tell you about "the wheel". Back around the 2006-2007 time frame I developed a product called the RTrak. This was an all-in-one box APRS tracker. It used the Argent Data Systems packet engine, a top shelf (at the time) Trimble Copernicus GPS receiver and the best low power VHF transmitter module that was ever on the market, the Small RF Budget MX145. I brought these all together to create what we thought was a pretty awesome device. Upon showing it off we immediately got bombarded with comments like "Finally! Someone did this!" and "When are they available? I'll take X number of units right now!".

So I spent a total of about six months and around $3000 in prototypes, as I perfected the design and made sure it was going to be shelf ready for shipping. Opened up for pre-orders and of the roughly 100-125 emails I got, I received seven, SEVEN orders. One, I found out was an editor for QST looking to do a full review article, which he did and it was published. I was told "Get ready for the orders to roll in!". A month after the article shipped, I had three, THREE more orders.

So I guess what I'm trying to tell you is, even when you think you have a NEW wheel, it can fall flat (no pun intended). Re-inventing the wheel is much more difficult and usually painful in the end. There is a lot of regret spending money, time, resources and blood on something that you coveted as your baby, just to have it rejected by and large by the mass majority of the market/community.

It's tough. That is why I have all but given up on the amateur market and focused my business and design efforts at the general electronics hobby building and believe it or not, the model railroader. I'm coming up with all kinds of electronics related items for that market. Yes, these are also two other hobbies I have a passion for and that does help.

One more thought: Back almost ten years ago, I had a pretty popular product that I promoted right here on the forums for long distance remote of the Uniden RH-96 remote control head. I sold a ton of them. Then Uniden discontinued the RH-96. My sales on that product dropped to zero. Even when I thought I had a hit, it was short lived and struck down in the prime of it's life by a circumstance completely out of my control.

 

[redbluff1099]

Check out PICO APRS device

 

[bagmouse7]

Thank you KENYV for this fantastic post. I appreciate your efforts overall, but I REALLY appreciate you sharing your real knowledge here.