From 3ae3479513e2dd0f664d2f56ad4c2a74bca1474c Mon Sep 17 00:00:00 2001 From: sh123 Date: Mon, 15 Nov 2021 10:32:00 +0200 Subject: [PATCH] Updated Protocol and compatibility (markdown) --- Protocol-and-compatibility.md | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/Protocol-and-compatibility.md b/Protocol-and-compatibility.md index b8c541d..460a1ee 100644 --- a/Protocol-and-compatibility.md +++ b/Protocol-and-compatibility.md @@ -22,7 +22,8 @@ At the link level, APRS uses the AX.25 protocol, as defined in AmateurPacket-Rad ## APRS compressed packets In compressed data format, the Information field contains the station’s latitude and longitude, together with course and speed or pre-calculated radio range or altitude. This information is compressed to minimize the length of the transmitted packet (and therefore improve its chances of being received correctly under less than ideal conditions). The Information field also contains a display Symbol Code, and there may optionally be a plain text comment (uncompressed) as well. -![alt text](https://raw.githubusercontent.com/sh123/esp32_loraprs/master/images/aprs_compressed.png) +![alt text](https://raw.githubusercontent.com/sh123/esp32_loraprs/blob/master/images/aprs_compressed.png) + # APRS TNC2 text protocol TNC2 protocol does not use KISS, it sends text based APRS messages, multiple messages are separated by using new line character `\n`. This is quite inefficient protocol for LoRa, because packet lengths are much longer compared to AX25, which causes longer TOA (time on the air).