PowerBox Mercury SRS with GPS: no telemetry

  • Hi everyone

    I am writing this post in English because it might be of interest for user Tadango who designed the FrSky adapter.

    I am building my first large aircraft and decided to buy a PowerBox Mercury SRS with GPS. I fly with FrSky and will keep my radio. Due to the lack of FrSky telemetry support I built the Ardunio Telemetry Adapter of user Tadango. Today I powered everything up on my workbench, and everything including telemetry like voltage of both packs are working fine. Only issue is the GPS, where I am not getting any data via telemetry, the items such as coords, altitude, etc. are available, but all remain zero.

    The GPS II first blinks and on the display it says "GPS: Search". After a while the LED turns solid and the display says "GPS: Ok". So I believe the GPS is technically working. The GPS is connected to the "GPS" port of the PowerBox Mercury SRS, on the side. I then consulted the manual and now I am confused.

    - The GPSII manual states I need to connect the GPS to the receiver. Is that for other PowerBoxes without GPS port?

    - The GPSII manual states I would need to configure the GPSII according to the telemetry protocol in use, which in my case (if wired to the Rx) would be SBUS. Am I correct that it should work out of the box when connected directly to the PowerBox?

    - The GPSII manual refers to an included Y-cable. I did not get a Y-cable with the "PowerBox Mercury SRS incl. GPS", just a simple patch cable which I used to connect the GPS to the PowerBox.

    Any ideas?

    - Furthermore is there a description of all telemetry values (5110, etc.) available? I know how to code, but it seems I am getting a few telemetry values which are not yet covered and I'd like to include them all.

    Nebenbei: Stimmt es, dass weder im Handbuch, der PowerBox selbst noch sonstwo steht, wie rum die Servostecker eingesteckt werden müssen? Anhand von Bildern im Internet habe ich es herausgefunden, aber der Ansatz ist nicht wirklich state-of-the-art. ;)

    Thanks a lot


  • Hallo Richard

    Ja bei der Mercury SRS. Diese kleinen Phasen an den Steckern hat meines Wissens nur Futaba. Sehr viele andere (eigentlich alle, die mir untergekommen sind) inklusive namhafter Hersteller wie MKS haben diese Phasen nicht. Ich habe es gerade ausprobiert, MKS geht problemlos ganz einfach auf beide Seiten.

  • The code only shows the GPS sensors if the GPS is detected, so it must be connected to the Powerbox correctly. The powerbox also shows a GPS OK status? Try removing all sensors on the TX, remove the GPS and then power up and discover sensors again. It should not show the GPS sensors. Now plugin the GPS and they should appear.

    You can find the sensor codes in the arduino code:

    - 0x5110 Distance

    - 0x5120 Travelled

    - 0x5130 RX1 Errors

    - 0x5140 RX1 Errors

    - 0x5150 Lost frames

    - 0x5160 Holds

    You can also test the GPS without the powerbox. Just connect the GPS to the adapter and it should only give you the GPS sensors. The GPS must be in Powerbox mode also (the same as when connecting to the Powerbox).

  • GPS is connected to the PowerBox Port "GPS" on the Mercury SRS. The receiver is connected to the RX1 port, display shows "RX1: Ok". SPort cable is connected to the Arduino Mini Pro which in turn is connected to the "TELE" port of the Mercury. The display shows "GPS: OK", when the LED on the GPS goes solid green.

    I have nothing else connected to the Rx. I deleted all sensors in the Taranis and rediscovered them, the sensors show, but no values for GPS, except for 5110 showing values of 1 to 25. I do get correct values for the two battery voltages. Amp draw stays 0.00A no matter how many big servos I attach to the SRS Mercury. That the amp draw does not work makes me suspect that there might have been a software change regarding telemetry? I am running V10 on my Mercury SRS, it was delivered that way.

    Here is a picture of my setup on the workbench.

  • No, the Mercury does not have current sensors so it always shows 0. The 5110 sensor is distance so that looks to be working (it is jumping arround a bit). Telemetry should not have changed in any version.... But try the GPS directly. You only need to add power but you can use a free servo port for that.

  • Where should I plug in the GPS? As far as I understand according to the manual, plugging in the GPS anywhere else than into the PowerBox would require to change the protocol used, hence requiring me to buy the USB adapter first and make myself a Y-cable that was not included in the SRS Mercury/GPS combo?

  • GPS gets a lock.

    Coordinates on Taranis stay at 0°00'N0°00'E.

    GSpd 0.0kts (kinda expected)

    GAlt 17m (I am at 700+ above sea level, don't know if altitude is absolute or relative)

    and I get the following unnamed sensors:







    I downloaded the file from Github and flashed the file

    with installed SPort library. I get a warning on compliation but it does not look critical. And that the battery voltages of the PowerBox (when connected) come through is an indication that it generally works, right?

  • I ordered the PowerBox USB adapter yesterday and luckily (thanks @ brack.ch) already got it today. I have just checked the firmware on the GPS, it already has the latest version on it, V0.1.6. Since voltage of both batteries are coming trough to my radio, the PowerBox OLED shows "GPS: OK" and the GPS LED goes solid green I highly suspect there is something to be adjusted in the GPS code in Tadango's adapter.

    Herman, have you got an idea?