Posts by oh2uds

    Hi all,


    I would like to test LoRa on QO-100... I know LoRa is not an open protocol, but it might be good to test these low bandwidth long range devices.


    e.g. https://www.semtech.com/produc…less-rf/lora-24ghz/sx1280 SX1280 can be the first candidate to test...


    I do have these questions in mind;

    - how dan we easily downconvert the received 10GHz signal to 2.4Ghz for reception

    - what will be the effect of latency (~1second) for a LoRa transceiver

    - Can we transpond very weak LoRa signals over QO-100 (if we can reach the transponder with a certain level I guess yes, but what is that level?)



    73's de OH2UDS / TA7W

    Baris

    There are many possibilities I guess... With stock firmware;


    If you use WIFI, you can configure your router/modem to explode your device to internet (using NAT/PAT). Wifi interface gets the default GW to be the access point (your modem/router)


    73's de OH2UDS/TA7W

    Baris

    Last time we sent the pictures from children to QO-100 and space, this time the payload will be the messages from young students with

    their voice..



    This activity is open to everyone... You will get a attendancecertificate if you record and report one of the FOX Transmissions..

    Dear All,

    "I WANT TO ANNOUNCE AN ACTIVITY THAT WILL HELD ON QO-100 THIS WEEKEND, MAYBE YOU ALREADY KNOW OUR TEAM FROM THE QO-100 KGSTV ACTIVITY (https://marsonearthproject.org/kg-stv-activity-result/)"


    During these pandemic days we wanted to have another activity for children and families who are at home and away from their friends.


    We wanted initiate an awareness about hamradio and space communications while playing an old hamradio game altogether on a satellite transponder.


    Foxhunting (also known as radio direction finding) is a field game under normal circumstances, where there are hidden and randomly transmitting tiny transmitters in a big field which I trying to be found by the attendees. When you find a transmitter location (called fox) you get points which means you hunt a fox. We don’t harm any animal during this activity. Please visit http://ardf.fi/ en for a sample activity held in Finland.


    This time, because of pandemic situation, we will not have a chance to be outdoors. Like our previous QO-100 KGSTV activity we wanted to hunt the foxes on our geostationary satellite transponder QO-100. This time we will be at home, monitoring the QO-100 downlink frequencies. Here is the story and procedure to be part of this activity:

    • Random SSB voice transmissions will be conducted on QO-100 SSB transponder portion,
    • Transmission times will be randomized withing the given activity hours,
    • Transmission frequencies will be random within a few frequency range,
    • You will try to capture and record the transmissions as good and long as possible (hunt the fox),
    • This transmission will include a chiled’s voice recording with his/her message to space and a secret letter for this challenge,
    • Sending these recordings and the secret word (refer to rules) to us will reward you with an award for the activity.


    Activity Date & Time

    15 May 2021 15:00 UTC to 17:00 UTC

    16 May 2021 15:00 UTC to 17:00 UTC


    Rules

    • Participants can use any reception technology (e.g. direct reception with dish + legacy radio and/or SDR radio, any web SDR, any remote station),
    • There is no age restriction,
    • The following frequency ranges will be used (randomly);
      • 10489.670 – 10489.680 MHz
      • 10489.700 – 10489.710 MHz
      • 10489.770 – 10489.780 MHz
      • 10489.810 – 10489.820 MHz
    • The Mars On Earth Project will do transmission for 1 (one) minute on any of the spot frequencies at a random schedule/time,
    • Transmission will be in USB modulation,
    • Transmission will include the following information (voice),
      • Transmission will start with alternating tones for 3 seconds (to be spotted easily),
      • Transmitting radio identification (OH2UDS or OH2CAV),
      • Message from a child to SPACE, who is part of “eTwinning Education Project”,
      • The message will end with a hint for the secret word, e.g : “and the secret letter is ……..”,
      • End of transmission with alternating tones transmission,
    • You need to record the message as long as possible,
    • You need to capture the secret letters as well. Combining secret letters will give you the secret word.


    FOR MORE DETAILS PLEASE VISIT : https://marsonearthproject.org…ting-on-qo-100-satellite/


    73's de TA7W/OH2UDS

    Baris

    I had another GND strike on my second PLUTO today... This time I was not so lucky. I lost the laptop computer totally.... And the pluto..

    I can still have console on plutor using the JTAG Rx and TX pins but this time the USB chip looks died (USB3320C-EZK).


    The internal LDO 3v3 is not providing output so the device assumes itself in OTG mode.... I will try to replace the USB3320C-EZK


    Yes exactly true.... and got the second strike and lost the USB3320 this time.... I checked that the FPGA side is still alive by connecting JTAG.. and after replacing the USB3320 the device came back alive "once more"...... I will be much more carefull this time...



    73's de OH2UDS/TA7W

    Baris Dinc

    I had another GND strike on my second PLUTO today... This time I was not so lucky. I lost the laptop computer totally.... And the pluto..

    I can still have console on plutor using the JTAG Rx and TX pins but this time the USB chip looks died (USB3320C-EZK).


    The internal LDO 3v3 is not providing output so the device assumes itself in OTG mode.... I will try to replace the USB3320C-EZK

    I re-solder the F1 fuse back.. This allows the device to sense the USB connection..


    after resoldering F1, when I put the device into DFU mode (press user button and plug in usb power) I was able to see the dfu interface on usb (id 0456)..


    Then used the firmware and dfu-util to flash the latest firmware


    sudo dfu-util -a firmware.dfu -D pluto.dfu


    and the device started back to working as normal....


    sanother PLUTO recovered :)



    73's de OH2UDS/TA7W

    Baris

    I will document my progress here, someone else can face the same issue...


    I connected a serial/USB converter to RX and TX pins on the JTAG port (be carefull it is 1V8 , you may want to use a level shifter)..


    I used 3V3 USB serial converter (worse case to loose the whole device...)


    Now I have the console.... I will investigate why I don't see any action on the USB port side :(



    73's de OH2UDS / TA7W

    Baris

    HI,

    Good catch... I had the same problem.. And I started debugging.. I was seeing short circuit in powe rlines (even in USB input)...

    I thought the voltage selector U8 or U9 is the reason.. :( I didn't want to desolder them, because they were very tiny to resolder back.

    I never thought that it can be the L7.

    Desoldered U8 and U9 didn't give me a solution but then I was sure that it is L7.... Just in your photos it was shortcircuited internally. I just placed wires instead of the coil L7, and carried the USB power from P2 pin 1 (Data USB power pin) to D3 (or shorted L7 power lines). Also removed the F1 fuse and D2.


    What does all this mean... No voltage selection for data USB and/or Power USB plug.. Which means I cannot power USB ethernet or similar OTG devices.


    Now the device has LEDs back.... Checked the voltage test points and all seems fine. But LED1 is blinking twice every seconds and I cannot have the USB drive present on PC side.. even IIO_INFO command cannot find any device...



    Anybody with any ideas ?




    Thanks

    Baris DINC

    73's de

    OH2UDS / TA7W