u-blox EVK-M91-00-01, Руководство пользователя

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EVK-M91 - User guide
a transmission of 0x55 0x55 at the baud rate of 9600 Bd. Wait for at least 100 milliseconds
before the interface is ready to accept commands.
5.6 LED
On the front panel of the unit, a single blue LED shows the time pulse signal as well as the status
that device is supplied. The LED starts flashing one pulse per second during a GNSS fix. If there is
no GNSS fix, the LED will only be lit, without flashing.
5.7 Flash
EVK-M91 has an SPI flash that is connected to the u-blox M9 receiver. By default it can be used to:
• Store the current configuration permanently
• Save data logging results
• Hold AssistNow
™ Offline and AssistNow ™ Autonomous data
EVK-M91 has a 16-Mbit flash. However, only 5 Mbit of this is available for application use. The
remainder of the space is reserved for other features.
5.8 Super capacitor
The evaluation board includes a super capacitor to supply the backup power domain of the EVK-M91
and is charged whenever there is a power supply available, either via USB or the 14 pins connector.
The super capacitor provides backup power directly to the EVK-M91 V_BCKP power input in case of
no other V_BACKUP power supply is provided. When this 1 F capacitor is fully charged to 3.0 V, it can
provide backup power for about 10 hours (t=C*U/I=1*(3.0-1.65)/36uA=37,500 seconds -> 10 hours).
The 3.0 V V_BACKUP power supply can be used to provide power for any needed period of time while
evaluating for very long backup periods.
5.9 EXTINT
On the EVK-M91, the EXTINT signal is available on 14-pin connector, see sections 14-pin connector
and RS-232 for more information.
UBX-19056858 - R04 5 Device description Page 14 of 27
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