{"id":6282,"date":"2026-03-17T11:26:20","date_gmt":"2026-03-17T10:26:20","guid":{"rendered":"https:\/\/grodansparadis.com\/wordpress\/?p=6282"},"modified":"2026-03-17T11:26:20","modified_gmt":"2026-03-17T10:26:20","slug":"nano-second-timestamp","status":"publish","type":"post","link":"https:\/\/grodansparadis.com\/wordpress\/?p=6282","title":{"rendered":"nano second timestamp"},"content":{"rendered":"\n
\"black<\/a>
Photo by Andrey Grushnikov on Pexels.com<\/a><\/figcaption><\/figure>\n\n\n\n

The 64-bit nano second timestamp is now introduced for VSCP. This is what we often call a Unix timestamp with nano second resolution and which holds the number of nanoseconds since the epoch (January 1, 1970, 00:00:00 UTC<\/em>).<\/p>\n\n\n\n

The “old” format with separate bytes for year, month, day, hour, minute, second and a 32-bit microsecond timestamp was constructed that way to make it easy for very low-end devices to receive\/send time information. This is still possible as the format is preserved. But the new format will be promoted.<\/p>\n\n\n\n

Note that it is still possible to send a microsecond timestamp for devices that rely on it. Just multiply the value with 1000 and set it to timestamp_ns. Relative timestamps can easily still be used.<\/p>\n\n\n\n

Two header bits 9\/8 specify the frame format. They were originally set to 0b00 and would with the new format be set to 0b01. So when a new event is constructed they shoudl be set. The define VSCP_HEADER16_FRAME_VERSION_UNIX_NS<\/strong> in vscp.h does that. Priority is probably also bits that should be altered usually to VSCP_PRIORITY_NORMAL<\/strong><\/p>\n\n\n\n

Helpers to convert between the two formats are available in the helper library and in vscphelper.cpp and vscp-firmware-helper.c. They are<\/p>\n\n\n\n

int64_t
vscp_fwhlp_to_unix_ns(int year, int month, int day, int hour, int minute, int second, uint32_t microsecond);<\/em><\/strong><\/p>\n\n\n\n

and<\/p>\n\n\n\n

void
vscp_fwhlp_from_unix_ns(int64_t unix_ns,
int *year,
int *month,
int *day,
int *hour,
int *minute,
int *second,
uint32_t *microsecond);<\/em><\/strong><\/p>\n\n\n\n

year<\/strong> and month<\/strong> is still available in the event defines also if nanosecond timestamps are used. This to preserve the size of frames. It is recommended to set year=0xffff and month=0xff when the new timestamp is used. Still the frame versin bits in the header is the main detection to use for frame type.<\/p>\n","protected":false},"excerpt":{"rendered":"

The 64-bit nano second timestamp is now introduced for VSCP. This is what we often call a Unix timestamp with nano second resolution and which holds the number of nanoseconds since the epoch (January 1, 1970, 00:00:00 UTC). The “old” format with separate bytes for year, month, day, hour, minute, second and a 32-bit microsecond […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_crdt_document":"","jetpack_post_was_ever_published":false,"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_publicize_message":"","jetpack_publicize_feature_enabled":true,"jetpack_social_post_already_shared":true,"jetpack_social_options":{"image_generator_settings":{"template":"highway","default_image_id":0,"font":"","enabled":false},"version":2}},"categories":[13],"tags":[],"class_list":["post-6282","post","type-post","status-publish","format-standard","hentry","category-vscp"],"jetpack_publicize_connections":[],"jetpack_featured_media_url":"","jetpack_shortlink":"https:\/\/wp.me\/p4raCZ-1Dk","jetpack_sharing_enabled":true,"jetpack_likes_enabled":true,"jetpack-related-posts":[],"_links":{"self":[{"href":"https:\/\/grodansparadis.com\/wordpress\/index.php?rest_route=\/wp\/v2\/posts\/6282","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/grodansparadis.com\/wordpress\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/grodansparadis.com\/wordpress\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/grodansparadis.com\/wordpress\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/grodansparadis.com\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=6282"}],"version-history":[{"count":2,"href":"https:\/\/grodansparadis.com\/wordpress\/index.php?rest_route=\/wp\/v2\/posts\/6282\/revisions"}],"predecessor-version":[{"id":6285,"href":"https:\/\/grodansparadis.com\/wordpress\/index.php?rest_route=\/wp\/v2\/posts\/6282\/revisions\/6285"}],"wp:attachment":[{"href":"https:\/\/grodansparadis.com\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=6282"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/grodansparadis.com\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=6282"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/grodansparadis.com\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=6282"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}