Geo-fence for the WSRP Pico

Harry Zachrisson
Aug 14, 2020
1 min read

Updated: Sep 3, 2020

In the latest firmware (0.92) I have implemented geofencing that will avoid transmission when a Pico transmitter and it's balloon is over the UK, Yemen or North Korea.

I have had a few people ask me about it but have not had time do anything in that area until a couple of weeks ago when Matt Downs - 2E1GYP from Essex in the UK provided me with a working proof of concept C code and the Maidenhead Grids to use. This made the coding a whole lot easier and I have now been able to include it in to my WSPR transmitter firmware.

The change is not visible for the user in any way and there are no setting, it is just hidden in the firmware.

It is only in effect on my Pico transmitters.

Now when a Pico transmitter finds itself in one of the grids inside the geofence it will hold off on transmissions until it is outside again.

There is one exception to this rule and that is if a user has a pico running inside the geofence they can still do test transmissions on the ground with a pico as long as it is connected to a computer and the PC software is communication with the Pico over a serial port.

Here is a couple images that shows the areas of no transmission.

73's from Sweden

//Harry

22 Comments

Richard Fairman

Jun 27, 2021

Do you know which libraries and dependencies i need to update and upload the firmware for my WSPR Pico Unit. I can remove the UK Maidenhead grids in the code but compile/verify fails everytime even trying to unmodded firmware Regards Richard Fairman

Donald Giles

Jun 27, 2021

Replying to

Sorry, I mistyped the comment statement. Comments are preceded by // for individual lines or /* and */ to comment out an entire section.

Richard Fairman

Jun 21, 2021

can you direct me to the correct open source file for the wspr pico transmitter thanks

Donald Giles

Jun 26, 2021

Replying to

O.K. What version of the Arduino IDE are you using? Also, are you sure the firmware file is a source code file and not the hex precompiled file that Harry has on this site? Uncompiled Arduino code looks like C++. The hex files would look like gibberish to a regular person. Do you have another Arduino board? If so, hook it up to the computer, start your Arduino IDE and try to load and run the BLINK program that is listed in the Examples menu. Remember to change the board type and port if necessary. This seems to be difficult but once you get the routine down working with these little microprocessors is quite fun. I will be…

Richard Fairman

Jun 20, 2021

Thanks I'm not a programmer. Is this easy to do my Maidenhead locator is io75rx I've just ordered a wspr pic from you

Harry Zachrisson

Jun 20, 2021

Replying to

Pretty easy, just search the source code for that grid and remove and upload it to the Pico using the Arduino IDE. If you are unfamiliar with the Arduino software perhaps you can ask around for someone that can help you locally. I am tied up with a million tasks right now so can not help you other that give advise. 73 //Harry

Richard Fairman

Jun 20, 2021

Can geo fencing be temp disabled or adjusted. i want to test a pico unit in UK on solar without having to connect to usb The unit will always be at zero altitude during test so will not contravene UK ofcom regs Can geo fencing be disabled at low or zero altitudes i want to test the unit at the top of my garden during a 24 hour period with daylight and darkness

Harry Zachrisson

Jun 20, 2021

Replying to

Hi Richard. Yes, the source code is published so just go in the there and remove the grid square you are in.

Dwight Jones

Aug 15, 2020

Thank you Harry. This will help. It's good to see the LU7AA sight is working again, even if it is slow. I like the fact that I can forward a link to non-ham friends who can track my balloon without having to input information. The VK7JJ site is faster, but I'm reluctant to give that site to non-hams who would get lost before they ever see a map.

I plan to launch again tomorrow or next weekend. I have a few ideas about what went wrong last week. This time, we might succeed...