Wakeup_In Signal - Huawei ME909u-523 Hardware Manual

HUAWEI ME909u-523 LTE LGA Module
Hardware Guide
Figure 3-7 Connections of the RESIN_N pin
As the RESIN_N and POWER_ON_OFF signals are relatively sensitive, it is
recommended that you install a 10 nF–0.1 µF capacitor near the RESIN_N and
POWER_ON_OFF pins of the interface for filtering. In addition, when you design a
circuit on the PCB of the interface board, it is recommended that the circuit length not
exceed 20 mm and that the circuit be kept at a distance of 2.54 mm (100 mil) at least
from the PCB edge. Furthermore, you need to wrap the area adjacent to the signal
wire with a ground wire. Otherwise, the module may be reset due to interference.
RESIN_N
The ME909u-523 module supports hardware reset function. If the software of the
ME909u-523 module stops responding, you can reset the hardware through the
RESIN_N signal as shown in Figure 3-8 .When a low-level pulse is supplied through
the RESIN_N pin, the hardware will be reset. After the hardware is reset, the software
starts powering on the module and reports relevant information according to the actual
settings. For example, the AT command automatically reports ^SYSSTART.
Figure 3-8 Reset pulse timing

3.4.4 WAKEUP_IN Signal

Table 3-3 shows the definition of the WAKEUP_IN signal.
Issue 01 (2014-05-24)
The RESIN_N pin must not be pulled down for more than 1s. Otherwise, the ME909u-523
module will be powered off.
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Description of the Application Interfaces
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