{"id":28638843,"url":"https://github.com/liebman/esp32-gps-ntp","last_synced_at":"2025-10-05T19:13:52.168Z","repository":{"id":55484540,"uuid":"324607921","full_name":"liebman/esp32-gps-ntp","owner":"liebman","description":null,"archived":false,"fork":false,"pushed_at":"2022-02-06T19:48:02.000Z","size":1172,"stargazers_count":18,"open_issues_count":2,"forks_count":7,"subscribers_count":3,"default_branch":"master","last_synced_at":"2025-07-26T11:03:42.384Z","etag":null,"topics":[],"latest_commit_sha":null,"homepage":null,"language":"C++","has_issues":true,"has_wiki":null,"has_pages":null,"mirror_url":null,"source_name":null,"license":"mit","status":null,"scm":"git","pull_requests_enabled":true,"icon_url":"https://github.com/liebman.png","metadata":{"files":{"readme":"README.md","changelog":null,"contributing":null,"funding":null,"license":"LICENSE","code_of_conduct":null,"threat_model":null,"audit":null,"citation":null,"codeowners":null,"security":null,"support":null}},"created_at":"2020-12-26T17:57:13.000Z","updated_at":"2024-08-27T05:04:33.000Z","dependencies_parsed_at":"2022-08-15T01:20:50.434Z","dependency_job_id":null,"html_url":"https://github.com/liebman/esp32-gps-ntp","commit_stats":null,"previous_names":[],"tags_count":0,"template":false,"template_full_name":null,"purl":"pkg:github/liebman/esp32-gps-ntp","repository_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/liebman%2Fesp32-gps-ntp","tags_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/liebman%2Fesp32-gps-ntp/tags","releases_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/liebman%2Fesp32-gps-ntp/releases","manifests_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/liebman%2Fesp32-gps-ntp/manifests","owner_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/owners/liebman","download_url":"https://codeload.github.com/liebman/esp32-gps-ntp/tar.gz/refs/heads/master","sbom_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/liebman%2Fesp32-gps-ntp/sbom","scorecard":null,"host":{"name":"GitHub","url":"https://github.com","kind":"github","repositories_count":278504734,"owners_count":25997995,"icon_url":"https://github.com/github.png","version":null,"created_at":"2022-05-30T11:31:42.601Z","updated_at":"2022-07-04T15:15:14.044Z","status":"online","status_checked_at":"2025-10-05T02:00:06.059Z","response_time":54,"last_error":null,"robots_txt_status":"success","robots_txt_updated_at":"2025-07-24T06:49:26.215Z","robots_txt_url":"https://github.com/robots.txt","online":true,"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":"2025-06-12T19:08:04.647Z","updated_at":"2025-10-05T19:13:52.098Z","avatar_url":"https://github.com/liebman.png","language":"C++","funding_links":[],"categories":[],"sub_categories":[],"readme":"# This is an ESP32 NTP Server with DS3231 synched to GPS PPS signal\n\n**NOTE: This is functional but *very much* a work in progress at the moment.**\n\nThis is an [esp-idf](https://docs.espressif.com/projects/esp-idf/en/latest/esp32/index.html) app using [platformio](https://platformio.org/).\n\n## Some details\n\nSynching the DS3231 to the GPS is done with a small high level (level 5) interrupt handler in assembly.  This generates a timestamp and offset in microseconds tracking the active edges of the GPS PPS and RTC SQW signals.  This data is then fed in to a PID algorithm that will generate an offset value used to speed up and slow down the DS3231 RTC.  This keeps the DS3231 synced with the GPS to within a couple of microseconds.  As a side benifit it also tunes the DS3231's ocilator to reduce drift when GPS is unavailable.\n\n- [main](main) Contains the code\n- [kicad/esp-gps-ntp](kicad/esp-gps-ntp) contains the schematic and board designs in KiCad.\n- [kicad/display-adapter](kicad/display-adapter) contains the schematic and board design for a small adapter to config a single inline header connector to an IDC connector (for ribbon cable connection of display)\n\nThe display I'm using is [here](https://www.amazon.com/gp/product/B073R7BH1B)\n\n## Schematic\n\n![Schematic](images/esp-gps-ntp.jpg)\n","project_url":"https://awesome.ecosyste.ms/api/v1/projects/github.com%2Fliebman%2Fesp32-gps-ntp","html_url":"https://awesome.ecosyste.ms/projects/github.com%2Fliebman%2Fesp32-gps-ntp","lists_url":"https://awesome.ecosyste.ms/api/v1/projects/github.com%2Fliebman%2Fesp32-gps-ntp/lists"}