
To select the frequency use the SPI command sequence:
1. SPI cmd: (0x1A) (TX-freq.) (RX-freq.)
2. wait for EVENT signal and read status with SPI cmd: (0x0A)
To select the mode bit use the SPI cmd sequence:
1. SPI cmd: (0x11) (DDRC) (PORTC) (0x02) (systemConfig)
2. wait for EVENT signal and read status with SPI cmd: (0x0A)
Finally a System Reset with SPI command (0x01) will reset the device and apply the settings.
Caution: The device is delivered without mode configuration per default. Before the first usage
a configuration is required with the SPI commands described before. In addition to the
frequency and region settings the supply mode should be set with SPI command (0x11). When
using the device with 5V supply it has to be ensured that before using the RF transmit operation
the 5V supply mode is configured!
For the US mode the channel usage has to be initialized before the first RF command, i.e., the channel
configuration has to be stored in EEPROM:
1. SPI cmd: (0x22) (default data)
2. wait for EVENT signal and read status with SPI cmd: (0x0A)
3. System Reset with SPI command (0x01) will reset the device and apply the settings
4. SPI cmd: (0x23)
The SPI cmd (0x23) shall be applied after each wake-up/reset of the device but must keep a 20s wait
period before consecutive calls (due to FCC regulations).
When receiving a downstream data packet with 8 bytes the RSSI value is reported with byte no. 8. This
RSSI value is determined at device pin level and need adjustment for the system level when using an
external LNA. This offset value can be set with SPI cmd (0x24).
2.2. Operating Modes Overview
This section gives an overview of the operating modes supported by the Atmel® ATA8520E.
After connecting the supply voltage to the VS pin, the Atmel ATA8520E always starts in OFF mode. All
internal circuits are disconnected from the power supply. Therefore, no SPI communication is supported.
The Atmel ATA8520E can be woken up by activating the PWRON pin or one of the NPWRONx pins. This
triggers the power-on sequence which will set the event line PB6 to low. After the system initialization the
Atmel ATA8520E reaches the IDLE Mode.
The idle mode is the basic system mode supporting SPI communication and transitions to the other
operating modes.
The transmit mode (TX Mode) starts the data transmission using the payload data which has to be
previously written into the TX buffer with the SPI command “Write TX Buffer”. The data transmission is
started with the SPI command “Send Frame”. After transmitting the data frame, the end of the
transmission is indicated when the event pin PB6 switches to low and the device enters the idle mode
again.
Reading the device status with the “Get Status” SPI command clears the PB6 event line, setting it to high
level again.
Atmel Single-Chip SIGFOX RF Transceiver [DATASHEET]
Atmel-9409C-ATA8520E_Datasheet_Complete-09/2016
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