Update README.md

README.md

@@ -17,9 +17,9 @@ Locapack is distributed under the GPLv3 license. Please refer to the `LICENSE` f
 
 ### Packet general structure
 
-|    2B    |         2B        |    0/5B     |    1B (opt)   |  variable   |      1B       |            variable           |
-|:--------:|:-----------------:|:-----------:|:-------------:|:-----------:|:-------------:|:-----------------------------:|
-| `header` | `sequence_number` | `timestamp` | `movement_id` | `device_id` | `payload_len` | `localisation_packet_payload` |
+|    2B    |         2B        |    0/5B     |    1B (opt)   |  variable   |       1B       |      1B       |            variable           |
+|:--------:|:-----------------:|:-----------:|:-------------:|:-----------:|:--------------:|:-------------:|:-----------------------------:|
+| `header` | `sequence_number` | `timestamp` | `movement_id` | `device_id` | `payload_type` | `payload_len` | `localisation_packet_payload` |
 
 The `sequence_number` field is mandatory.
 
@@ -29,6 +29,8 @@ The `movement_id` field is optional and its presence is announced in the header.
 
 The `device_id` field length is annouced in the header. A length of 0 means that the field is not present in the packet, for example if the `device_id` is the same as the source address of the packet.
 
+The `payload_type` field contains the type of localisation packet in the payload.
+
 The `payload_len` field contains the length of the payload.
 
 The `localisation_packet_payload` length depends on the `localisation_packet_type` annouced in the header.
@@ -62,8 +64,8 @@ Transport of GNSS coordinates. Altitude and DOP are optionnal.
 
 ##### Payload general structure
 
-|    1B    |     4B      |     4B      |    0/4B    | 0/4B  |
-|----------|-------------|-------------|------------|-------|
+|    1B    |     4B     |     4B      |    0/4B    | 0/4B  |
+|----------|------------|-------------|------------|-------|
 | `header` | `latitude` | `longitude` | `altitude` | `dop` |
 
 The `latitude` field is a C-type float and is mandatory.