LTE-A Module Series
EM121R-GL Hardware Design
EM121R-GL Hardware Design 50 / 80
4.5.2. W_DISABLE2#
The module provides a W_DISABLE2# pin to disable or enable the GNSS function. The W_DISABLE2#
pin is pulled up by default. Driving it low will disable the GNSS function. The combination of
W_DISABLE2# pin and AT commands can control the GNSS function.
Table 23: GNSS Function Status
A simple level shifter based on diodes is used on W_DISABLE1# pin and W_DISABLE2# pin which are
pulled up to a 1.8 V voltage in the module, as shown in the following figure. So, the control signals (GPIO)
of the host device could be at 1.8 V or 3.3 V voltage level. W_DISABLE1# and W_DISABLE2# are active
low signals, and a reference circuit is shown as below.
Host
Module
W_DISABLE2#
W_DISABLE1#
BB
GPIO
GPIO
26
8
VDD 1.8 V
R5
10k
R6
10k
Note:
The voltage level of VCC_IO_HOST could be 1.8 V or 3.3 V typically.
VCC_IO_HOST
R2
100k
R3
100k
Figure 28: W_DISABLE1# and W_DISABLE2# Reference Circuit
High Level
AT+CFUN=0
AT+CFUN=4
Disabled
Low Level
AT+CFUN=0
AT+CFUN=1
AT+CFUN=4
Disabled
W_DISABLE2# Level
AT Commands
GNSS Function Status
High Level
AT+QGPS=1
Enabled
High Level
AT+QGPSEND
Disabled
Low Level
AT+QGPS=1
Low Level
AT+QGPSEND