RY835AI GPS Connections

[duecedriver]

Looking for definitive pinouts and settings based on the latest .5 beta code. These are the latest pinouts most are using but the RY835AI shows multiple trigger grounds... should we be using or tying the grounds to ensure proper operation? There are many people posting of intermittent signal, long lock times, and other abnormalities.. are we hooking this up right!

Also, does the stratux code set the units internal settings for gps refresh rates>? The unit comes factory default at 1HZ but can be modified up to 18Hz. How about baud rates and ports? Some hook up via usb then connect to gpoi and that solves some issues.. so I am thinking this is a gps board settings issue.

Does the hardware store almanac and ephemeris data for warm/hot and assisted startup or do we need to store that via software. I assume some settings (port data/refresh rates/etc) are being retained in the unit via non vol memory while catalog and gps ephemeris are being held by the rechargeable onboard battery. Anyone test how long that battery lasts?

as for the gyros and other sensors.. see my other post.. I believe there are sever good open source code projects that will give us full AHRS and imu/inu functionality.

Power: VDD -> PIN 02 GND -> PIN 06 AHARS Data: SDA1 -> PIN 03 SCL1 -> PIN 05 GPS Data: TXD -> PIN 10 RXD -> PIN 08

spec sheet here http://www.reyax.com/Module/GPS/RY835AI/RY835AI.pdf

[1-prop-head]

As for shielding. I am using some non conductive tap to cover the back of the REYAX board and then covering that with copper foil tape. The finishing step is to bond the foil with a wire connecting it to ground. This seems to work pretty good on the GPS antenna on my drone. But a drone has a lot more emf than the RPi.

[brockhoff]

I'm confused..... 1-prop-head states that REYAX has updated information concerning the NEO-M8N but gives a link to the u-box web site. Also, based on the RY835AI documentation and the NEO-M8N documentation it looks like the FSYNC pin has nothing to do with the NEO-M8N chip. From what I can read it looks like the FSYNC pin is going to the InvenSense MPU-6050 chip.

I do agree that all the grounds should be connected. What I have noticed is that if I run the RY835AI connected through the USB only it will receive 12 satellites most of the time. But if I run the RY835AI through the GPIO connection it will receive 4-5 satellites some times and other times it will loose all satellites.

[jamez70]

Use two irons we do that at work all of the time On Dec 22, 2015 9:43 AM, "1-prop-head" notifications@github.com wrote:

About those grounds. It is very difficult to get enough heat into the board to make a reliable solder flow connection on the grounds. The plated through ground connection holes are not buffered from the board and you are required to heat up a lot of copper to get a good flow. I am cranking my solder pencil up and still not getting a great feeling about the heat penetration on the ground connection

— Reply to this email directly or view it on GitHub https://github.com/cyoung/stratux/issues/142#issuecomment-166650872.

[1-prop-head]

Sorry u-box is the source of the info I used. I can only guess that the FSYNC in a unbound state may be causing the module to execute some extra unnecessary service routines. Thanks to all this is a great project

[duecedriver]

in an unbound state the voltage is allowed to float causing erroneous on/off states... clearly states in the integration docs to ground if not used...

in my opinion if this board is going to be used... all grounds need to be wired with none of the wires being routed under the board.. none.. not ground, power or signal. best solution would be to mount the RY chip to a GPIO breadboard HAT. the board needs to have a metal shield around it and grounded to the 4 corners of the board... the antenna needs to be surrounded by a gps ground plane that could be incorporated into the shielding.

the schematic of the RY chip shows some power filtering on the 5+ input and I believe that if i2c communications are not solid. proper i2c bus voltage pull-ups need to be put in place on the lines.

[duecedriver]

@brockhoff

correct, the fsync is for the 6050 and its i2c internal... but its still a ground and signal source so it should be wired correctly to prevent noise from entering the components.. any components on the board

[ScraboTower]

Dumb question, can you use USB just for GPS and GPIO for the AHRS ? I seen posts where users are reporting less than 12 satellites when using only the pins.

[cyoung]

You can

[duecedriver]

yep however I cant find on the spec sheet what the max update rates are over one vs there other.. and dont forget to harden the micro usb connector with some epoxy or something or it will break off in short order.

grounding of the board and shielding the board and giving the antenna a ground plane will improve even the usb connected device

On Dec 22, 2015, at 6:45 PM, cyoung notifications@github.com wrote:

You can

— Reply to this email directly or view it on GitHub https://github.com/cyoung/stratux/issues/142#issuecomment-166763554.

[wakkow]

I've seen numerous comments about usb working better for people than pins. Why would this be? It can't be grounding because the microusb header looks to connect to the same ground plane as everything else. It can't be the floating FSYNC pin, because it's it's floating when on usb (unless it's disabled via software?).

[duecedriver]

the usb standard would require the power and grounding and signal shielding etc.. the gps is still going out over the serial bus into the header pins witch require those wires to have good solder joints and the noise on the ground plane would be a bigger issue since the signal paths move about that ground plane...

or it could be a hardware issue on the reyax side if they didnt integrate the chip properly....

[tdarrow]

Can someone point me in the right direction. I am new to this. I have assembled the receiver with the GPS. I have made the connections in the post. I can see the GNSS LED flashing, but I am not getting GPS output. Am I missing something? Any help would be appreciated. If this is not the correct form, my apologies stratuxlog.txt .

[Axtel4]

Have you enabled the GPS in the Web UI?

[tdarrow]

Thanks for replying. Yes, everything is enabled. I am getting AHRS, traffic, and weather. The AHRS symbol is skewed, but I see that is still being worked on.

Sent from my iPad

On Feb 2, 2016, at 10:14 PM, Axtel4 notifications@github.com wrote:

Have you enabled the GPS in the Web UI?

— Reply to this email directly or view it on GitHub.

[Axtel4]

A couple of other things to try; Very the wiring between the RY and the R-Pi. The most common error is swapping the TX and RX lines.

Also, if the GNSS led is blinking and you still doing see any GPS data on the Web UI, try cycling power on the Pi. Sometimes it sherbet sync up with the GPS data if the GPS starts let. This was addressed in 0.5r4 or 0.5r5 but it doesn't hurt to reset.

On February 3, 2016 3:05:19 AM CST, tdarrow notifications@github.com wrote:

Thanks for replying. Yes, everything is enabled. I am getting AHRS, traffic, and weather. The AHRS symbol is skewed, but I see that is still being worked on.

Sent from my iPad

On Feb 2, 2016, at 10:14 PM, Axtel4 notifications@github.com wrote:

Have you enabled the GPS in the Web UI?

— Reply to this email directly or view it on GitHub.

---

Reply to this email directly or view it on GitHub: https://github.com/cyoung/stratux/issues/142#issuecomment-179107612

[braddward]

Does it work with the USB cable? That should tell you if it's your wiring or not.

[jzeevi]

Are there any advantages to direct wiring vs. using the RY835AI via USB?

From: braddward [mailto:notifications@github.com] Sent: Wednesday, February 03, 2016 8:33 AM To: cyoung/stratux Cc: Josef Zeevi Subject: Re: [stratux] RY835AI GPS Connections (#142)

Does it work with the USB cable? That should tell you if it's your wiring or not.

— Reply to this email directly or view it on GitHub https://github.com/cyoung/stratux/issues/142#issuecomment-179266853 . https://github.com/notifications/beacon/APJ34TkeoVsguIfXCjOEFQClWejRLOdaks5pggcggaJpZM4G0UuQ.gif

[braddward]

I don't know if the AHRS works with USB. Also, I've heard that the USB connection on the RY835AI is very fragile and can't take any stress.

On Wed, Feb 3, 2016 at 8:44 AM Josef Zeevi notifications@github.com wrote:

Are there any advantages to direct wiring vs. using the RY835AI via USB?

From: braddward [mailto:notifications@github.com] Sent: Wednesday, February 03, 2016 8:33 AM To: cyoung/stratux Cc: Josef Zeevi Subject: Re: [stratux] RY835AI GPS Connections (#142)

Does it work with the USB cable? That should tell you if it's your wiring or not.

— Reply to this email directly or view it on GitHub < https://github.com/cyoung/stratux/issues/142#issuecomment-179266853> . < https://github.com/notifications/beacon/APJ34TkeoVsguIfXCjOEFQClWejRLOdaks5pggcggaJpZM4G0UuQ.gif>

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[JohnOCFII]

Are there any advantages to direct wiring vs. using the RY835AI via USB?

It frees up a USB port for a different use. Remember too, the USB connection can only connect the GPS portion, not the AHRS portion of the RY835AI.

[jzeevi]

Got it. For me, as a Foreflight user, that’s currently not a problem. I’ll look at direct wiring, though – seems like that offers more opportunity. J

Thanks!

From: JohnOCFII [mailto:notifications@github.com] Sent: Wednesday, February 03, 2016 9:00 AM To: cyoung/stratux Cc: Josef Zeevi Subject: Re: [stratux] RY835AI GPS Connections (#142)

Are there any advantages to direct wiring vs. using the RY835AI via USB?

It frees up a USB port for a different use. Remember too, the USB connection can only connect the GPS portion, not the AHRS portion of the RY835AI.

— Reply to this email directly or view it on GitHub https://github.com/cyoung/stratux/issues/142#issuecomment-179277743 . https://github.com/notifications/beacon/APJ34dugemLikbM6XDFD3Vc85bZ2B6dwks5pgg1egaJpZM4G0UuQ.gif

[tdarrow]

I tried both way, and did not receive any data. I'm not sure if I have a bad chip. I tried to check it with the ublox center, but I could not get it to see the sub ports.

Sent from my iPad

On Feb 3, 2016, at 9:33 AM, braddward notifications@github.com wrote:

Does it work with the USB cable? That should tell you if it's your wiring or not.

— Reply to this email directly or view it on GitHub.

[braddward]

were you able to disconnect the hard-wired connections? If you did and it still doesn't work sounds like you may have a bad board then.

On Wed, Feb 3, 2016 at 10:09 AM tdarrow notifications@github.com wrote:

I tried both way, and did not receive any data. I'm not sure if I have a bad chip. I tried to check it with the ublox center, but I could not get it to see the sub ports.

Sent from my iPad

On Feb 3, 2016, at 9:33 AM, braddward notifications@github.com wrote:

Does it work with the USB cable? That should tell you if it's your wiring or not.

— Reply to this email directly or view it on GitHub.

— Reply to this email directly or view it on GitHub https://github.com/cyoung/stratux/issues/142#issuecomment-179316705.

[Nokomis449]

On the RY, you should get a solid light at power up (I think it's green), and then once it receives a GPS lock it blinks (i think red) once a second. I may have the colors reversed, but there's a green one and a red one; a solid one and a blinking one. You can't get a blinking one without a solid one. You only mentioned a blinking light. Are you seeing both?

[braddward]

One last thing - you may want to leave it on for an extended period in a place where you know it can pick up a signal (by a window or even outside if you can). Others have discussed that it can take significant time for it to figure out where it is initially after it's trip from China. Once it's got that solution it's battery backed up. I've also heard that the battery backup on the chip doesn't last a long time either.

On Wed, Feb 3, 2016 at 10:40 AM Nokomis449 notifications@github.com wrote:

On the RY, you should get a solid light at power up (I think it's green), and then once it receives a GPS lock it blinks (i think red) once a second. I may have the colors reversed, but there's a green one and a red one; a solid one and a blinking one. You can't get a blinking one without a solid one. You only mentioned a blinking light. Are you seeing both?

— Reply to this email directly or view it on GitHub https://github.com/cyoung/stratux/issues/142#issuecomment-179332715.

[tdarrow]

I checked the connections. I had to switch the transmit and receive around. As soon as I did that I has GPS signal. I then shut the pi down so that I could reassemble the case. Now I have the green power led, but no red flashing led. When I look at the status on the web page I see the following

UAT towers 0 GPS solution No Fix GPS satellites 0 in solution; 3 seen; 10 tracked

I am currently letting it sit next to a window to see if there is any change Once again, thanks for your help.

Sent from my iPad

On Feb 3, 2016, at 11:58 AM, braddward notifications@github.com wrote:

One last thing - you may want to leave it on for an extended period in a place where you know it can pick up a signal (by a window or even outside if you can). Others have discussed that it can take significant time for it to figure out where it is initially after it's trip from China. Once it's got that solution it's battery backed up. I've also heard that the battery backup on the chip doesn't last a long time either.

On Wed, Feb 3, 2016 at 10:40 AM Nokomis449 notifications@github.com wrote:

On the RY, you should get a solid light at power up (I think it's green), and then once it receives a GPS lock it blinks (i think red) once a second. I may have the colors reversed, but there's a green one and a red one; a solid one and a blinking one. You can't get a blinking one without a solid one. You only mentioned a blinking light. Are you seeing both?

— Reply to this email directly or view it on GitHub https://github.com/cyoung/stratux/issues/142#issuecomment-179332715.

— Reply to this email directly or view it on GitHub.

[scmadden]

I have never gotten a signal from my RY835AI. Lights are on and blinking but not GPS, no AHRS. I have radio ADS-B hits but no positions.

[skypuppy]

Send it to me and I'll test it for ya.

On 02/05/2016 01:42 PM, scmadden wrote:

I have never gotten a signal from my RY835AI. Lights are on and blinking but not GPS, no AHRS. I have radio ADS-B hits but no positions.

— Reply to this email directly or view it on GitHub https://github.com/cyoung/stratux/issues/142#issuecomment-180515006.

[jamez70]

You could try cat /dev/ttyACM0 (is that it?) With gen_gdl90 stopped On Feb 5, 2016 4:13 PM, "skypuppy" notifications@github.com wrote:

Send it to me and I'll test it for ya.

On 02/05/2016 01:42 PM, scmadden wrote:

I have never gotten a signal from my RY835AI. Lights are on and blinking but not GPS, no AHRS. I have radio ADS-B hits but no positions.

— Reply to this email directly or view it on GitHub https://github.com/cyoung/stratux/issues/142#issuecomment-180515006.

— Reply to this email directly or view it on GitHub https://github.com/cyoung/stratux/issues/142#issuecomment-180593367.

[skypuppy]

Or minicom or cutecom, or etc. I'm thinking it is more of a hardware problem, but local tests should be run first, of course.

On 02/05/2016 04:24 PM, jamez70 wrote:

You could try cat /dev/ttyACM0 (is that it?) With gen_gdl90 stopped On Feb 5, 2016 4:13 PM, "skypuppy" notifications@github.com wrote:

Send it to me and I'll test it for ya.

On 02/05/2016 01:42 PM, scmadden wrote:

I have never gotten a signal from my RY835AI. Lights are on and blinking but not GPS, no AHRS. I have radio ADS-B hits but no positions.

— Reply to this email directly or view it on GitHub https://github.com/cyoung/stratux/issues/142#issuecomment-180515006.

— Reply to this email directly or view it on GitHub https://github.com/cyoung/stratux/issues/142#issuecomment-180593367.

— Reply to this email directly or view it on GitHub https://github.com/cyoung/stratux/issues/142#issuecomment-180597560.

[scmadden]

When I connect it to my computer I get a gps signal. Just not coming through the stratux.

[wakkow]

@scmadden USB or GPIO? If GPIO, try USB and see if you get anything.

[scmadden]

I have tried both. GPS connection just this afternoon broke.

Shawn C. Madden, Ph.D. Major, USMC (retired) On Feb 5, 2016 5:30 PM, "Daniel Whiting" notifications@github.com wrote:

@scmadden https://github.com/scmadden USB or GPIO? If GPIO, try USB and see if you get anything.

— Reply to this email directly or view it on GitHub https://github.com/cyoung/stratux/issues/142#issuecomment-180620548.

[cyoung]

Try Reddit or Slack if further support needed.