LPWA Module Series
BG77 Hardware Design
BG77_Hardware_Design 46 / 76
BG77 provides a USB_BOOT pin. During development or factory production, USB_BOOT can force the
module to boot from USB port for firmware upgrade.
Table 21: Pin Definition of USB_BOOT Interface
The following figure shows a reference circuit of USB_BOOT interface.
Figure 22: Reference Circuit of USB_BOOT Interface
It is recommended to reserve the above circuit design during application design.
3.17. ADC Interfaces
The module provides two analog-to-digital converter (ADC) interfaces.
AT+QADC=0
command can be
used to read the voltage value on ADC0 pin.
AT+QADC=1
command can be used to read the voltage
value on ADC1 pin. For more details about the AT command, please refer to
document [2]
.
In order to improve the accuracy of ADC voltage values, the trace of ADC should be surrounded by
ground.
Pin Name
Pin No.
I/O
Description
Comment
USB_BOOT 87
DI
Force the module to enter into
emergency download mode
1.8V power domain.
Active high.
If unused, keep it open.
NOTE
