Configuration , issues and furture features updates following use of the project.

[sivaelid]

First It’s a great Project and has some unique aspects, and the use of accurate sub frequency is a real game changer, so many thanks for the project.

The project has some very interesting uses and the main one I am Interested in, is in the use Pi Pico Ballon WSPR, just using the Pi Pico and GPS. This reduces the weight of the balloon package as does not need a separate RF package and only Band Pass Filter.

I have now had some time now using the latest 1.01 code. I have some comments below and future requests.

Setting up and use of Current code:

First the information as a newbie was not clear. I would be happy to give some information as a Wiki if that would help.
• The diagram in the pin out shows the connection of the GPS to Pins 1 and 2 of the Pi Pico this is incorrect is should be Rx – GPIO13 Tx – GPIO12. The Rx of the Pi Pico should be connected to the Tx of the GPS module and Tx of Pi Pico to the Rx of the GPS.
• The diagram shows a Neo6m GPS module. It is noted that this GPS module due to age only output $GPRMC messages. Most modern GPS module that are Multi-satellite are outputting $GNRMC messages. You need to check the output of the GPS module to see the output message type for yours if not using Neo6M. If you want to change the NEMA message to the more common $GNRMC type then this can be done in “GPStime.c” currently line 224.
• Configuration is carried out in the Main.c for the most part, and it will be good that it can be configured with the coming Console configuration.

Current issues

1. While the start of the WSPR messages are perfectly locked to time sequence (start time and Slot interval, The Tx frequency is not stable being received and is varying by about 20Hz. I am not sure if this is the nature of the receiving stations or the transmission. I see another comment on the pf-hf- oscillator code.

Future Request

With my slant on use for Pico Ballons that will be legal in the UK in 2024, It would be nice to see:

1. That the NEMA message used to sync and as time source is $GP(N)GGA as this include the Altitude component and this can then be substituted for Tx Power when divided by 300.This is a standard trick for Balloons using WSPR.
2. Sleep ( Dormant) mode ( useful for all activities), such as remote WSPR test where there is no long term power and can be done using the library like https://github.com/raspberrypi/pico-extras/blob/master/src/rp2_common/pico_sleep/sleep.c Though there are many others as well as on the Pi Site. It would be nice to make the module sleep until say 5-10 seconds before WSPR Message start time to let GPS settle and output messages and after message sent and unit goes to sleep when WSPR> Passive Tx Slot .
3. Ability to Tx on several bands to check propagation e.g. 40m,20m,10m by transmitting on each band say at 2, 4, 6 minutes passed the hour and then repeat the sequence. I see some commercial projects do this.
4. Easy Configuration of the key parameter. While it is easy to config the main.c, there may be other configuration needed like $Gpxxx or $Gnxxx NEMA messages types that can not be set in Main.c

Anyway thanks for your skills in coding this and its nice to see a community of interested users.

Simon G8HAM

[edegraaff]

Hi Simon, youre thinking in same directions. WSPR over different bands, with intervals would be great. For HAB should you not also would like to make reuse of the gps coordinates. Thinking loud, pi pico, wspr, 2 extra components one gps and one pressure/temp sensor would to the job? Solar cells?