AT86RF211DB-868LT Atmel, AT86RF211DB-868LT Datasheet

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AT86RF211DB-868LT

Manufacturer Part Number
AT86RF211DB-868LT
Description
BOARD DAUGHTER AT86RF211/868MHZ
Manufacturer
Atmel
Datasheet

Specifications of AT86RF211DB-868LT

Module/board Type
Daughter Board
For Use With/related Products
AT86RF211 @ 866MHz
Lead Free Status / RoHS Status
Contains lead / RoHS non-compliant
Other names
AT86RF211-DB868107
AT86RF211DB868107
AT86RF211DB868107
AT86RF211DB868LT
Why an Update of
this Application
Note?
Stand-alone Wake-up Mode Protocol. Rev. 2
Power Management Using the Embedded
The embedded wake-up mode of the AT86RF211 offers
a lot of possibilities to users. The aim of this Application
Note Revision 2 is to provide with a simple and effective
way of implementing the wake-up mode, to save time
and money.
All the wake-up functions are based on the Header rec-
o g n i t i o n a n d a n a l y s i s : t h e 1 0 b i t s s e q u e n c e
(1010100001) is searched before any wake-up, and the
data rate "extracted" thanks to an embedded algorithm.
In order for it to operate properly, the duration of the "0"
and "1" must be close one to the other within a given
tolerance.
Meeting this "duty cycle" requirement over all operating
conditions is very easy at the transmitter side because
any microcontroller is able to generate an output frame
with an excellent precision (Timer Output Compare for
instance). At the receiver side, it is made easier by using:
Before using another implementation make sure to con-
tact Atmel’s FAE before.
a data rate ≤ 10 kbps: the longer the bits, the easier.
Since it is possible to wake-up a device at 10 kbps
and to transfer the data at 64 kbps afterwards, and
thanks to the wake-up time based on RSSI checking,
the additional power consumption is totally negligible.
the ''external'' mode for the data slicer (the
demodulated signal is compared to its average value
stored into an external capacitor). The duty cycle
remains excellent even if the external conditions
have changed between two wake-up timeslots with
no need for data slicer level adjustment.
Consequences: lower requirements on the rest of the
hardware (cost reduction) and shorter development
time (simpler software).
AT86RF211
(TRX01)
FSK
Transceiver for
ISM Radio
Applications
Application Note
Rev. 2186A–WIRE–08/02
1

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AT86RF211DB-868LT Summary of contents

Page 1

... At the receiver side made easier by using: • • Before using another implementation make sure to con- tact Atmel’s FAE before. a data rate ≤ 10 kbps: the longer the bits, the easier. Since it is possible to wake-up a device at 10 kbps and to transfer the data at 64 kbps afterwards, and thanks to the wake-up time based on RSSI checking, the additional power consumption is totally negligible ...

Page 2

Principle of the Embedded Wake-up Procedure Reception mode Oscillator settling Sleep mode Sleep Mode = Very Low Power Mode AT86RF211 (TRX01) 2 The "peak" consumption in Receive (Rx) or Transmit (Tx) mode of any high-perfor- mances transceiver makes it necessary ...

Page 3

... WAKEUP bit of STATUS reg- ister is also set. As indicated before, Atmel suggests that the wake-up mode should be implemented with a very short WL1 ( make sure that PLL is locked & RSSI conversion com- pleted). This way: • ...

Page 4

Notes typical value that depends on the crystal's specifications (the user does not have to care about that: oscillator set- tling is automatically detected by AT86RF211). 2. Full correct message means: Header correct (mandatory) + ...

Page 5

... Since it is possible to wake-up a device at 10 kbps and to trans- fer data at 64 kbps afterwards (see above), and thanks to the wake-up time based on RSSI checking, the additional power consumption is negligible. Please contact Atmel’s FAE if application requires a higher data rate during the wake-up phase. ...

Page 6

Demodulated signal on DISCOUT pin AT86RF211 (TRX01) 6 Comparison level set on SKFILT pin Data Slicing Options Comparison level set by internal DAC (DSREF) DATAMSG + - Internal comparison mode: the signal is compared to a fixed level DATAMSG Signal ...

Page 7

... Loop Filter 2186A–WIRE–08/02 Atmel recommends: • The ''External'' Mode for the Data Slicer: since the demodulated signal is compared to its average value, stored into an external capacitor, the duty cycle remains naturally very close to 50% even if the external conditions (i.e. temperature) have changed between two wake-up timeslots, with no need for data slicer threshold re-adjustment ...

Page 8

... Use of RSSI Threshold and Hysteresis AT86RF211 (TRX01) 8 Atmel recommends using: • [( 3.3 kΩ 560 pF] if the maximum data rate of the application (wake-up phase + data transfer afterwards) does not exceed 10 kbps. • [( kΩ 100 pF] if the data rate during the data transfer exceeds 10 kbits/s. This filter also works well during the wake-up phase (< ...

Page 9

Clock Recovery of the Wake-up Error Detection 2186A–WIRE–08/02 This clock recovery process must not be confused with the clock recovery of the normal communication receive mode, giving an output clock on DATACLK pin. The wake-up clock recovery gives no output ...

Page 10

Message Format Expected Message's Format FIELD HEADER (1) Length 10 bits Value 1010100001b Set-up Processing of Header must be received data correct to go further Usage Mandatory Make sure to meet chapter “Practical Implementation” on page 5 requirements for data ...

Page 11

The received Data (if any) is stored into WUD register and available for the microcontroller. The read of this data deactivates the wake-up pin (as well as WAKEUP flag of STATUS register). Warning: the first data bit received (LSB bit: ...

Page 12

Set- Transceiver and Initialization of a "Sleep" Procedure Relevant Registers Procedure to Put a Transceiver to Sleep AT86RF211 (TRX01) 12 All wake-up parameters are set-up as wanted at the beginning of the application by writ- ing into the ...

Page 13

How to Wake-up (a) Distant Device(s)? General Rules Typical Applications Individual Addressing 2186A–WIRE–08/02 As indicated in chapter 1-2: • WL2 must be > message duration, to make sure to catch it • wake-up message duration must be > ...

Page 14

Group Addressing (no Data Field) AT86RF211 (TRX01 WUC: WUE = '1', DATA = '0', STOP = '0', DATL = '00000', ADD = '1', MSGTST = '0', WPER = '0 0110 0011', WL1 = '000 0001', WL2 = '010', ...

Page 15

Group Addressing (with Data Field) 2186A–WIRE–08/02 - WUA: ADD = '0000 0000 0000 0xxx xxx0' (6 bits in bold depending on the device), ADDL = yyyyy depends on the target devices to be reached: '0 0110' (individual), '0 0011' (whole ...

Page 16

Addressing by "Data rate" (individual or group) AT86RF211 (TRX01 WUC register: WUE = '1', DATA = '1', STOP = '0', DATAL = '01001', ADD = '1', MSGTST = '0', WPER = '001100011', WL1 = '0000001', WL2 = '011'. ...

Page 17

... The capacity of a battery is given in A.h that corresponds to an electric charge ( t measured with given discharges conditions (discharge current final voltage). Atmel assumes that in practical half of this value can be really used because of current constraints of the application (operating voltage > 2.4V, self discharge, T°...). Let's call Qb = Q/2 ...

Page 18

... Number of 4181 ms cycles = 4.7 10 sponding to 6 years ± 20% (± 1.2 year). • With a single transmitter, the chip must send the data each time (so every 4.2 s) With the same parameters, during each 4.2 s cycle Atmel has: – 8 ms: oscillator settling time, the consumption is 0.8 mA. – ...

Page 19

... No licenses to patents or other intellectual property of Atmel are granted by the Company in connection with the sale of Atmel products, expressly or by implication. Atmel’s products are not authorized for use as critical components in life support devices or systems. ...

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