{"id":28691730,"url":"https://github.com/mineinjava/ffellowship","last_synced_at":"2026-02-03T21:30:55.091Z","repository":{"id":292625359,"uuid":"981452935","full_name":"Mineinjava/ffellowship","owner":"Mineinjava","description":"Frequency Fellowship: Examining Radio Wave Propagation from a High Altitude Balloon","archived":false,"fork":false,"pushed_at":"2025-06-21T21:59:41.000Z","size":4293,"stargazers_count":1,"open_issues_count":0,"forks_count":0,"subscribers_count":1,"default_branch":"main","last_synced_at":"2025-06-21T22:29:32.816Z","etag":null,"topics":[],"latest_commit_sha":null,"homepage":"","language":null,"has_issues":true,"has_wiki":null,"has_pages":null,"mirror_url":null,"source_name":null,"license":null,"status":null,"scm":"git","pull_requests_enabled":true,"icon_url":"https://github.com/Mineinjava.png","metadata":{"files":{"readme":"README.md","changelog":null,"contributing":null,"funding":null,"license":null,"code_of_conduct":null,"threat_model":null,"audit":null,"citation":null,"codeowners":null,"security":null,"support":null,"governance":null,"roadmap":null,"authors":null,"dei":null,"publiccode":null,"codemeta":null,"zenodo":null}},"created_at":"2025-05-11T06:17:07.000Z","updated_at":"2025-06-21T21:59:44.000Z","dependencies_parsed_at":"2025-05-11T19:36:51.509Z","dependency_job_id":"5fd04ce8-f22c-457b-b250-4ff042c35347","html_url":"https://github.com/Mineinjava/ffellowship","commit_stats":null,"previous_names":["mineinjava/ffelowshp","mineinjava/ffellowshp","mineinjava/ffellowship"],"tags_count":0,"template":false,"template_full_name":null,"purl":"pkg:github/Mineinjava/ffellowship","repository_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/Mineinjava%2Fffellowship","tags_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/Mineinjava%2Fffellowship/tags","releases_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/Mineinjava%2Fffellowship/releases","manifests_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/Mineinjava%2Fffellowship/manifests","owner_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/owners/Mineinjava","download_url":"https://codeload.github.com/Mineinjava/ffellowship/tar.gz/refs/heads/main","sbom_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/Mineinjava%2Fffellowship/sbom","scorecard":null,"host":{"name":"GitHub","url":"https://github.com","kind":"github","repositories_count":286080680,"owners_count":29058190,"icon_url":"https://github.com/github.png","version":null,"created_at":"2022-05-30T11:31:42.601Z","updated_at":"2026-02-03T20:13:53.544Z","status":"ssl_error","status_checked_at":"2026-02-03T20:13:40.507Z","response_time":96,"last_error":"SSL_read: unexpected eof while reading","robots_txt_status":"success","robots_txt_updated_at":"2025-07-24T06:49:26.215Z","robots_txt_url":"https://github.com/robots.txt","online":false,"can_crawl_api":true,"host_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub","repositories_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories","repository_names_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repository_names","owners_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/owners"}},"keywords":[],"created_at":"2025-06-14T07:14:12.430Z","updated_at":"2026-02-03T21:30:55.086Z","avatar_url":"https://github.com/Mineinjava.png","language":null,"readme":"# ffellowship\nFrequency Fellowship: Examining Radio Wave Propagation from a High Altitude Balloon\n---\n\nThis is a project for Hack Club's [Apex](https://apex.hackclub.com),\nmade by:\n- [Marcus Kauffman](https://kauffman.tools) KN6UYL (@mineinjava)\n- Hudson Hilal (@hhilal123)\n- Joshua Truman (@jstruman4929)\n\nWe initially had two project ideas for Apex: this and dropping what was\neffectively a lawn dart from 100,000 feet. After the lawn dart project\nwas rejected, we submitted this project.\n\nMany high altitude balloons (HABs) have been launched, almost all of\nwhich have some sort of tracker that transmits the balloon's location.\nThese transmissions are received by stations on the ground and then\nuploaded to the internet, from which we can view the locations of\nreceiving stations for analysis. Our goal for this project is to study\nthe differences between different tracker design techniques,\nspecifically:\n\n- Does radio band selection influence likelihood of reception?\n    - Receiving stations on the 2m band are much more common than those\n      on the 20m band, but 20m transmissions theoretically travel\n      farther.\n- There are three common methods of modulating signals:\n    - Connecting to a dedicated radio for transmission\n    - Using a MS5351M or similar clock generator IC\n    - Using [fancy PLL](https://github.com/kaduhi/pico-fractional-pll)\n      to \"bit-bang\" the radio waveform\n\n    **Question: do these three modulation methods have a significant\n    difference in quality and therefore propagation?**\n- How do different antenna designs affect propagation.\n\nDue to customs issues, we were only able to test the PLL tracker \nwith three antenna wavelengths. Two of the frequencies had issues \n(unresolved ATM), so we instead analyzed the effect of height on \nradio wave propagation.\n\n\nAs suggested above, this project can easily be divided into three\n\"sub-projects\":\n\n## 1. Use of the MS5351M Clock Generator IC.\n\nThis subproject revolves around the MS5351M clock generator. It features\na custom PCB. Note that this tracker will transmit on both the 20m and\n2m bands because the MS5351M has multiple clock generators.\n\nThis tracker has quite a few features, many of which are to support\nultra-low power operation, as is common with this style of tracker:\n\n- GPS\n- Temperature/pressure sensor\n- Shunt\n- 3v3 buck-boost converter\n- power supervisor to restart the pico\n- Sensors can be powered off to conserve power.\n\nThis PCB is designed around the Raspberry Pi Pico due to its rigorous\ntesting and ease of integration. It also features mainly 1206 components\nto aid in manual reflow soldering of the PCB.\n\nSee the dPicoTracker/ directory for more info.\n\n\u003cimg width=\"45%\" alt=\"image\" src=\"https://github.com/user-attachments/assets/7f470492-ae92-42a6-9955-464c4acf6c3a\" /\u003e\n\u003cimg width=\"15%\" alt=\"image\" src=\"https://github.com/user-attachments/assets/3d54dc78-25ee-414b-87be-a32b8e5429ea\" /\u003e\n\u003cimg width=\"15%\" alt=\"image\" src=\"https://github.com/user-attachments/assets/0fcfec73-e802-4580-a60f-e8776f611511\" /\u003e\n\n## 2. Use of PLL:\n\nThis subproject uses the Raspberry Pi Pico to generate RF signals,\n*without the use of a dedicated radio/chip*. It is by far the simplest\ndesign and features a power supervisor, optional low-pass filter, \nbattery measurement circuitry, as well as a GPS which is essential \nfor correcting oscillator drift.\n\n\u003cimg width=\"45%\" alt=\"image\" src=\"https://github.com/user-attachments/assets/f9456a09-8f7e-4147-b86d-2dbddf85e924\" /\u003e\n\u003cimg width=\"25%\" alt=\"image\" src=\"https://github.com/user-attachments/assets/fd3d784c-5ae2-43be-bc79-20a70b61c0f0\" /\u003e\n\u003cimg width=\"25%\" alt=\"image\" src=\"https://github.com/user-attachments/assets/05025c67-159f-4369-ba2f-c38484b891e7\" /\u003e\n\n\n## 3. Use of a Dedicated HT Radio.\n\nThis subproject uses a Raspberry Pi Zero W and a custom PCB to connect\nto a HT, which will be stripped down to save weight. \n\nThe PCB consists of a voltage regulator to power the Pi and a 555 timer\ncircuit to ensure that transmissions are limited in time (in case\nof a software crash).\n\n\u003cimg width=\"45%\" alt=\"image\" src=\"https://github.com/user-attachments/assets/36d1860b-98f9-4235-a175-2ab4391e6281\" /\u003e\n\u003cimg width=\"25%\" alt=\"image\" src=\"https://github.com/user-attachments/assets/dac293cd-b379-4ed7-8f10-603090a213a1\" /\u003e\n\u003cimg width=\"25%\" alt=\"image\" src=\"https://github.com/user-attachments/assets/eae42010-35e1-4933-8691-403493354298\" /\u003e\n\n\n## Integration:\n\n*coming soon*\n\n## Project Status:\n\n*coming soon*\n","funding_links":[],"categories":[],"sub_categories":[],"project_url":"https://awesome.ecosyste.ms/api/v1/projects/github.com%2Fmineinjava%2Fffellowship","html_url":"https://awesome.ecosyste.ms/projects/github.com%2Fmineinjava%2Fffellowship","lists_url":"https://awesome.ecosyste.ms/api/v1/projects/github.com%2Fmineinjava%2Fffellowship/lists"}