/g/HABalloon

Re: New to Pico Ballooning

kenndaniel@... (Ken Daniel) — Sun, 27 Feb 2022 17:35:27 -0800

Here is a project that I have been working on and off for a few years. I have flown it 5 times. It hasn't made it around the world yet. I have three more ready to go up soon. I will put the software in git by the end of the week.

Re: Sketch Size

kenndaniel@... (Ken Daniel) — Sun, 27 Feb 2022 17:00:54 -0800

The newest version of JTEncode is significantly larger so my Atmega 328P code would no longer fit. I needed to downgrade to v 1.21. The newer version is a more complete implementation of the wspr standard, but I don't need any addditional features for my tracker.

Ken.

Re: Sketch Size

rk3att@... — Wed, 17 Nov 2021 08:25:56 -0800

Big thanks for the answers. The problem resolved itself, apparently it is related to libraries. I started it on another computer and everything went well.

Re: Sketch Size

stephenpackermd@... (Steve P) — Wed, 17 Nov 2021 07:08:46 -0800

You can also use this on other arduino comparable boards, Esp32, teensy etc. they all have larger memories and more horsepower. If you want to reduce the size you’ll likely have to eliminate some of the features. If you don’t need JT9 mode for instance or can slim down the timing code. You just have to go through the code and remove what you don’t need taking care that you adjust the rest of the code to make sure you don’t break it by removing a dependency for something else.

I wrote the original code some years ago and have since been working on a better version with significantly different encoding and likely on newer hardware. It’s all still a work in progress and time permitting though.

Re: Sketch Size

kari.mcclure1@... (Kari McClure) — Wed, 17 Nov 2021 07:02:07 -0800

Here are a few general tips for reducing code size.

https://oscarliang.com/arduino-sketch-too-big-error-reduce-sketch-size/

--
======================
Brian McClure
Amateur Radio: NW4R
brian.mcclure@...

"Nothing is quite as dangerous or unpredictable as an engineer with
too much time on his hands."

Re: Sketch Size

david.sprague@... (Dave Sprague) — Wed, 17 Nov 2021 05:15:34 -0800

I'm not an active contributor on this group but it would probably be useful if you posted a description of what the sketch does and a source listing of the sketch. Someone might spot a way to reduce the sketch size somehow.

If there's a large library that's contributing to the size, maybe you could find a simpler library that does what you need?

Sketch Size

rk3att@... — Tue, 16 Nov 2021 19:00:22 -0800

Hello. I apologize for the stupid question, i need to somehow reduce the size of the sketch so that it fits on Atmega 328P?

The sketch uses 33776 byte (109%) of memory.

New to Pico Ballooning

@... — Tue, 04 May 2021 10:12:06 -0700

Just wanted to say hello to everyone and ask a question.
I am just now getting into Pico Ballooning and want to build my own tracker w/WISPr
Is there anywhere on the web that shows how to build a Pico payload with 'off the shelf items.
(Not using a custom board). I know it is a weight thing so maybe it is not possible.
I have built quite a lot a amateur radio kits but no SMT parts.
Everything I have found with Arduino off the shelf seems like the full sized stuff for camera balloons
not floaters. Any help would be appreciated.

Thanks,

Harold N8RQJ

Re: Unable to Decode WSPR Generated by SI5351 Project

groups.io@... (kc2svq) — Thu, 01 Apr 2021 09:41:26 -0700

Thanks for responding Ken. I'll look more closely at my setup and see if I need to adjust transmit frequency to be in band.

Re: Unable to Decode WSPR Generated by SI5351 Project

k9wis@... (B C) — Wed, 31 Mar 2021 07:31:43 -0700

I heard a program on NPR yesterday about a bunch of scientists using trackers on birds. He said they use a store and forward method using a cell fone chip to dump a days worth of data in a text message to the scientist. It sounded like they were battery powered and used a GPS chip like we do,

He mentioned the trackers were about the size of a matchbook so I am guessing the birds they are tracking are large, like geese or large seabirds.

Brian K9WIS

-----------------------------------------

From: "Ken Daniel via groups.io"
To: [email protected]
Cc:
Sent: Tuesday March 30 2021 7:12:57PM
Subject: Re: [HABalloon] Unable to Decode WSPR Generated by SI5351 Project

Hi Mikael,

I have a lot of experience using Si5351 on a breadboard using Adafruit and Amazon versions. I even though the frequency of the crystal and transmit frequency is set correctly the signal is typically out of band. This is due to the inaccuracy of the crystal. The width of the band is only 200 Hz. In the past I have had to fudge the transmit frequency to bring it into the band. Typically the SI 5351 has two 3 inch pieces of wire for an antenna. I use a standard ham setup for 20 m to receive it e.g. transmitter and tuned up antenna.

When I power using the usb from a desktop computer, I get a lot of spike side bands that are easy to see.

Ken

K9YO

Re: Unable to Decode WSPR Generated by SI5351 Project

kenndaniel@... (Ken Daniel) — Tue, 30 Mar 2021 17:26:59 -0700

Hi Mikael,

I have a lot of experience using Si5351 on a breadboard using Adafruit and Amazon types. Even though the frequency of the crystal and transmit frequency is set correctly the signal is typically out of band. This is due to the inaccuracy of the crystal. The width of the band is only 200 Hz. In the past I have had to fudge the transmit frequency to bring it into the band. Typically the SI 5351 has two 3 inch pieces of wire for an antenna. I use a standard ham setup for 20 m to receive it e.g. transceiver and tuned up antenna.

When I power using the usb from a desktop computer, I get a lot of spike side bands that are easy to see.

Ken

K9YO

Re: Unable to Decode WSPR Generated by SI5351 Project

kenndaniel@... (Ken Daniel) — Tue, 30 Mar 2021 17:12:57 -0700

Hi Mikael,

When I power using the usb from a desktop computer, I get a lot of spike side bands that are easy to see.

Ken

K9YO

Re: Unable to Decode WSPR Generated by SI5351 Project

roberto.pietrafesa@... (Roberto Pietrafesa) — Tue, 30 Mar 2021 15:08:42 -0700

Hello Jeff.

About the TX frequency, you must set it somewhere between 14097000 and 14097200, in these 200 Hz bandwidth reserved for WSPR transmissions.

The one who could mislead you is the so-called "dial frequency" that is 14095600 for WSPR on the 20 meters band.

But, what does it mean "dial frequency" ?

It means the frequency you set on your radio display, so that is the frequency "where the USB zero starts".

Let me explain: when you set your radio to receive digital signals in the USB (Upper Side Band) the radio itself set the receiving band of 3000 Hz from "dial frequency" to "dial frequency + 3000 Hz".

So, if you set dial frequency to 14095600, as per my suggestion, your radio will have a bandpass from 14095600 to 14098600 Hz.

Well, the center of this range (14095600 to 14098600) is exactly in the middle, or rather 14097100. So, the WSPR range is exactly 14097100 +/- 100 Hz, meaning 14097000 to 14097200.

This last range (14097000 to 14097200) is EXACTLY where the software WSJT-X (or another wspr decoder if any) will look at to find any wspr signal!

Hope this helps.

Enjoy your balloons!

73 de IZ7VHF

Roberto

Re: Unable to Decode WSPR Generated by SI5351 Project

mikael_dagman@... (Mikael Dagman - SA6BSS) — Tue, 30 Mar 2021 15:04:59 -0700

Hi, its always hard do say what to do just seeing some pictures but I notice two things, first it looks to me you have to set the correct wspr freq, 14095600 is the dial freq, the transmitted signal is 1400-1600hz up so you need to set something like
#define WSPR_FREQ 14097120UL, secondly it looks to me the wspr tx is to long, longer then the ca 2min it should take to tx a wspr frame, check that you have set the CTC setting to corresponds to the speed of the xo driving the 328,

#define WSPR_CTC 1334 // CTC value for WSPR // 10672 @ 16Mhz //5336 @ 8Mhz //2668 @ 4Mhz //1334 @ 2Mhz //667 @ 1Mhz

/M

Re: Unable to Decode WSPR Generated by SI5351 Project

groups.io@... (kc2svq) — Tue, 30 Mar 2021 15:02:30 -0700

Hi Harry,

Thank you for your time and response.

It seems that my signal wasn't at a WSPR frequency, but rather at 14MHz. I failed to change WSPR_FREQ in the HABalloon code. Once updated it appears I have a signal right at about 14.0956 MHz.

Screenshots of the updated results are in another posting, if your interested and have the time.

Thank you,
Jeff

Re: Unable to Decode WSPR Generated by SI5351 Project

groups.io@... (kc2svq) — Tue, 30 Mar 2021 14:54:42 -0700

Hi Mikael,

Thanks for your time. I think the xo speed was a good hint. I'm doing a mock-up using the Adafruit SI5351 breakout board. The board has a 25MHz TXCO, but I noticed that the HABalloon code was set for 27 MHz. So I made that correction. Also, someone mentioned that my signal seemed off target frequency, so I looked through the code and found WSPR_FREQ set for 14000000 MHZ, so I adjusted that to be 14095600. Now I get a signal that seems to be in the filter frequency path. I believe it may be WSPR, but not sure as I can't seem to find a good Waterfall diagram of a WSPR signal, online.

Still not decoding in WSJTX, however. Looking at the waterfall, it appears to me that I may be overdriving the receiver, particularly considering the receiver and SI5351 are directly connnected, no antennas. I'm going to try an attenuator and see what happens.

In the mean time, here are some updated pics of waterfalls. Thanks for your time.

TY,
Jeff

Re: Unable to Decode WSPR Generated by SI5351 Project

harry@... (Harry Zachrisson - SM7PNV) — Mon, 29 Mar 2021 13:04:17 -0700

Hi Jeff.

The first screenshot shows some signals between 3100 and 3500Hz but the WSPR reception only works if they are between 1400 and 1600Hz so perhaps you are not correctly tuned?

The traces also look like they have a lot of drift on them, the lines should be absolutely straight and not slanted as in your first screenshot.

//Harry

Re: Unable to Decode WSPR Generated by SI5351 Project

mikael_dagman@... (Mikael Dagman - SA6BSS) — Mon, 29 Mar 2021 12:35:11 -0700

Hi, it looks like you are listening in on the 10th overtone or something, thats usually what it looks like then, also its way out of wspr band pass but that will probably sort when you get it going like it should be.

Dont know gqrx but as you can decode other stations thats a good indicator that your rx is correctly setup.

First thing that comes to mind, what speed of the xo for the 5351 are you using? have you checked you have it corresponds to the speed set in the ict fw?

/Mikael

Unable to Decode WSPR Generated by SI5351 Project

groups.io@... (kc2svq) — Mon, 29 Mar 2021 12:17:37 -0700

To Whom It may Interest:

I am working on a high altitude balloon tracking project using the firmware of this project. The mock-up of the circuitry includes the Arduino/SI5351 with a uBlox GPS receiver.

To test the mock-up the SI5351 antenna output feeds to an RTL-SDR.com USB TV receiver at 20m/14MHz. GQRX is my SDR receiver software, feeding WSJTX. I believe my computer time is correct.

When I connect the RTL-SDR to a rooftop antenna, I receive and decode WSPR from several locations, including Europe; I am near NYC. However, when I connect the RTL-SDR directly to my SI5351, I seem to receive the signal all the way through to WSJTX, but it doesn't get decoded.

I'm not sure where to go from here, what to change, or what to test. Any help is appreciated. Some screenshots to settings and current results are attached.

FWIW, Some of the things I have tried:
- calibrating WSJTX to RTL-SDR: slope and intercept
- GQRX Input Hardware AGC and LNA adjustments (off and 0 for direct to SI5351)
- GQRX Audio Gain adjustments (-50dB, 0dB, 50dB)
- GQRX Receiver AGC adjustments (fast and off)

Thx,
Jeff

Re: GPS for ICT

mikael_dagman@... (Mikael Dagman - SA6BSS) — Thu, 04 Mar 2021 09:33:26 -0800

It will work fine with vcc on pin 7 of the atgm, and I would recommend you put vcc on pin V_bat pin 6 of the atgm but it will work fine without.

/Mikael