GETTING STARTED
Dragonfly
TM
MTQ-LSP3-B03 Device Guide
25
Powering Down Your Device
CAUTION:
Failing to properly power down the device before removing power may corrupt your device's file
system.
To properly power down your device, do one of the following options:
Option 1:
:
1.
Issue the AT#SHDN command.
2.
Wait 30 seconds.
3.
Power off or disconnect power.
Note:
If you send AT#SHDN and do not remove power AND the ONOFF line is high, the radio restarts after 60
seconds.
Option 2:
1.
Hold signal ONOFF (processor pin PC13) low.
2.
Monitor signal VDD1_8_MON (processor pin PC5). When it goes low, the radio is powered off and it is
safe to remove power.
Device Reset (NRESET Pin 35)
NRESET pin 35 of the 40 pin connector is routed directly to NRST on the STM32F413RH processor.
There are two components to reset:
1.
Processor Reset
Multiple reset methods are available. Refer to STM32F413RH documentation for details.
2.
Radio Reset
The STM32F413RH processor pin PC_13 is routed to a tiny9 supervisory processor that controls the radio.
If PC_13 is driven low for >50ms and <1s, the radio is reset.
If PC_13 is driven low for >1s, the radio is powered down.
Resetting the Processor
To reset the processor, the minimum recommended reset pulse is 200
μ
s. The maximum reset pulse is less
than 1 second.
Refer to STM32F413RH documentation for additional reset options available within the on-board
microcontroller.
- Reset is controlled via PC13 on the on-board microcontroller.
- Refer to 3G_ONOFF Signal for instructions on managing radio module reset.
Sleep Mode
Control radio sleep mode with the GPIO pin PC13 (3G_ONOFF) on the onboard processor. See also
3G_ONOFF
Signal
.
Setting PC13 to Low and holding it low turns the radio off, causing it to draw minimal power.
Setting PC13 to High resets and wakes up the device.
