Rx Mode; Tx Mode - Semtech LR1110 User Manual

2.1.4 RX Mode

The RX mode allows the reception of incoming RF packets on the RFI_N_LF0/RFI_P_LF0 pins in the sub-GHz band
(150-960MHz), using one the modems (LoRa® and (G)FSK). The device enters the RX mode using the command SetRx( ). At
packet reception, an RX_DONE interrupt is generated, and the received data is stored in the device data buffer. The RX
operation can be automatically terminated after a packet reception, duty-cycled, or infinite based on the application
requirements.
While in RX mode, the LR1110 can operate in different sub-modes:
•
In continuous mode, the device remains in RX mode and looks for incoming packets until the host requests a different
mode.
•
In single mode, the device returns automatically to a configured mode (to Standby RC by default) after a packet
reception only.
•
In single with timeout mode, the device returns automatically to a configured mode (to Standby RC by default) after a
packet reception or after the given timeout time. If a sync word (G)FSK or a LoRa® header is detected, the timeout is
stopped.
•
In RX Duty Cycle mode, the device goes periodically into RX mode to receive a packet before going back to Sleep
mode, until a packet was received. The used clock source for the RTC has to be configured with a command before
entering the Duty Cycle mode.
•
In AutoTx mode (auto transmit one packet after a given time on packet reception), the device goes into an
intermediary mode for the requested time after a packet reception, before entering TX mode for the transmission of
the packet.

2.1.5 TX Mode

The TX mode allows the transmission of RF packets using the selected sub-GHz PA on the RFO_LP_LF or RFO_HP_LF pins
in the sub-GHz band (150-960MHz), using the modems (LoRa® and (G)FSK).
After ramping-up the PA, the LR1110 transmits the data buffer at the given frequency, PA, output power and packet and
modulation configurations. When the last bit of the packet has been sent, a TX_DONE interrupt is generated, the PA
regulator is ramped down, the selected PA is switched OFF and the device goes back to Standby RC or Xosc modes,
depending on the FallBackMode configuration.
In TX mode, BUSY will go low as soon as the PA has ramped-up and transmission of the preamble starts.
While in TX mode, the LR1110 can operate in different sub-modes:
•
In single mode, the device returns automatically to a configured mode (to Standby RC by default) after a packet
transmission.
•
In single mode with timeout, the device returns automatically to a configured mode (to Standby RC by default)) after
the transmission of the packet or after the given timeout.
•
In AutoRX mode, the device goes into an intermediary mode for the requested time after a packet transmission, before
entering RX mode for reception of one packet or until the configured timeout.
•
In Continuous Wave mode (CW mode), the device indefinitely transmits the carrier frequency until another command
is issued to change the mode.
•
In Infinite preamble mode: the device indefinitely transmits an infinite preamble of the configured modulation.
LR1110
User Manual Rev.1.0
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