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Diffstat (limited to 'libloragw/readme.md')
| -rw-r--r-- | libloragw/readme.md | 16 |
1 files changed, 16 insertions, 0 deletions
diff --git a/libloragw/readme.md b/libloragw/readme.md index 337ad5b..7d398ee 100644 --- a/libloragw/readme.md +++ b/libloragw/readme.md @@ -48,6 +48,22 @@ use the LoRa concentrator: For an standard application, include only this module. The use of this module is detailed on the usage section. +/!\ When sending a packet, there is a 1.5 ms delay for the analog circuitry to +start and be stable (TX_START_DELAY). + +In 'timestamp' mode, this is transparent: the modem is started 1.5ms before the +user-set timestamp value is reached, the preamble of the packet start right when +the internal timestamp counter reach target value. + +In 'immediate' mode, the packet is emitted as soon as possible: transferring the +packet (and its parameters) from the host to the concentrator takes some time, +then there is the TX_START_DELAY, then the packet is emitted. + +In 'triggered' mode (aka PPS/GPS mode), the packet, typically a beacon, is +emitted 1.5ms after a rising edge of the trigger signal. Because there is no +way to anticipate the triggering event and start the analog circuitry +beforehand, that delay must be taken into account in the protocol. + ### 2.2. loragw_reg ### This module is used to access to the LoRa concentrator registers by name instead |