System Blue Not Working
Hey Everyone,

I have a System Blue (PCB 19.3).  The system does not seem to be working.  I have everything soldered up according to the instructions... When I plug it in the following happens:

- Solid Red Power Light on main PCB.
- Solid Light on both E and H field boards.
- GPS light (on PCB, not the blue LED soldered on) blinks like 7 times and just then off.

I have a grounding clamp connected to the outside of the RG6, seemed a good place to ground. 

That's all that seems to happen.  LAN is not active (no lights on router or PCB RJ45 network connector).

Is this normal? If I have bad GPS reception (this is on my work bench in basement) will the unit fail to boot?


No, it does not sound normal. I do not have an answer, but I have some more questions.

Do you have a copy of the schematic diagram? It is available on this forum from Project Area / Compendium, and will help you out lots!

Can you ping your device, does it show up on a port scan, or on the configuration page of your router? Maybe it is alive for a few seconds, then dies.
What is the rating of your USB power supply?
Can you measure the supply voltages on the board from the header connector? If yes, what are they? 

The 5V line  on my system is around 4.6-4.7V. The 3.3V line is between 3.25V and 3.31V.

Your GPS will probably not work well in the basement, although mine was fine indoors. 

Related to this question, roughly where in the world are you, some old versions of the firmware had problems in Australia and Japan.

I might not be able to help you out with these answers, but it might get other minds working!
Stations: 1515
Am I right in saying that you don't get any other LEDs cycling when you first turn on the power? From memory half turn on solid for about a second, then the other half, then the buzzer will beep indicating it's booted. After that the mode and Ethernet LEDs should light solid, along with 1pps GPS when it has a lock. If none of this happens, it's probably a firmware issue. Follow the instructions in the build document to connect the board to your PC via the mini USB port and use the ST software to manually flash a firmware file.

My PCB 19.3 did boot initially with no problems, but the firmware was too old resulting in errors in the web UI. Yours could be a similar case of a bad or incorrect initial firmware load.
Stations: 1614
5V power supply is 1A and measures 5.08V. The 3.3V measures in at 3.27V. Should be good to go. Upon further inspection I found that I am missing the R825 resistor. Looks like it should be 1k ohm. Was this intentional? Could this be causing it? Looks like it is on one of the USB data pins...

Edit: Also, not planning to keep GPS in basement, but I want to get this thing running before I go on a wire fishing expedition. I wouldn't think a GPS fix would be necessary for this to boot, pull an IP, etc.

Edit 2: Thanks piepants. Getting pretty late here (US East). Going to shut it down and try to flash tomorrow. I am concerned about the missing resistor. Can you check your 19.3 to see if yours is there? I may need to solder one on...
R825 is a pull-up resistor on the USB D+ line. I can't look up the STM32 docs at the moment, but it seems to have something to do with getting the CPU to enter DFU bootloader mode when connected to USB. On the System Blue, as per the documentation you enter DFU mode by holding the BOOT0 and Reset buttons so I believe this resistor is not required, but Egon can probably clarify that.

I'll check mine when I get home from work.
Stations: 1614
I can confirm R825 is unpopulated on my System Blue (PCB 19.3).

When you apply power, the LEDs should illuminate in this sequence (with Power always on):

1. Mode, Network, GPS (with a low beep)
2. Fault, Alarm
3. Mode, Network (if connected), Fault
4. A high beep will sound when fault turns off again.

Have a go at following the DFuSe firmware update procedure in the assembly instructions, hopefully that fixes it Smile

Attached Files Thumbnail(s)
Stations: 1614

think I had the same problem...NO firmware loaded :-(

After that everything was fine...   :-)
73 de Hartmut / DK5LH

Stations: 1582
(2016-09-27, 09:14)elythomaslumber Wrote: Hi,

think I had the same problem...NO firmware loaded :-(

After that everything was fine...   :-)

Here a short description for those who will have the same problem when receiving a board without pre-installed FW:
- download the "DfuSe Demo-Software" and follow the instructions as descriped in the system blue manual
- in my case the driver was not found and not installed! Therefore look where the SW was installed: maybe c:\program File (x86)\STM microelectronics...
- here you will find the drivers for manually installation
- now after successfully installing drivers everything should work as described in the system blue manual...but for those who have the same PCB 19.3 board as's not the correct SW but seems to be running
73 de Hartmut / DK5LH

Stations: 1582
Here is the latest DFU Firmware file:

DFU flashing is very simple and is described here:

Good luck! Smile
Stations: 538, 1534, 1712, 2034, 2219, 3044
I had contacted Egon (THANKS EGON!!!!) and he pointed me at the crystals. I had to swap the crystals during assembly (since I had put them on backwards before noticing they were different) and in the process damaged the 8MHz crystal.  I ordered another, and swapped that out.  Works now 100%

Thanks everyone for tips and tricks.  I am sure I will be back in the antenna deployment stage with more questions!
Great news! What sort of antenna are you building?

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