User guide

37
[a]: When Battery is low or battery pack is detached, PDA goes to sleep after displaying "battery runs out or
battery pack is detached".
: At this moment, application should close the COM Port and cut the power to the External Device (Refer to
the technical document we provided in the past) by receiving below event.
Namely, COM port: close and PWR_EN: off
* PWR_EN: Driver should set the pin status of PWR_EN to low to disable the serial buffer for preventing
possible leakage current.
* In the case of battery detached or low battery
- Things to do in the application
#define WM_BATTERY_OFF WMUSER+4955
case WM_BATTERY_OFF:
[b]: In order to set the pin status of PWR_EN to Low, the provided driver should be loaded using below code
in the application.
HANDLE hPWRDevice;
HANDLE hPWR= 0;
hPWRDevice=RegisterDevice(
TEXT("XXX"), //device identifier prefix
1, //device identifier index
TEXT("pwrdrv.dll"), //device driver name
0); //instance information (passed to XXX_Init)
if (hPWRDevice)
{
hPWR=CreateFile(_T("XXX1:"),
signal (3.3V)
Serial port buffer = to
switch between ext device
and ext serial because the
COM8 is shared.
* High signal: Buffer on
* Low signal: Buffer off
M
4
DTR O Low
High
(Port should
be open)
OS makes
it Low
OS keeps
the
status
before
sleep
Application
should close
the COM
port
Output- Active high signal
(3.3V)
Depending on the status
of COM Port, OS handles
DTR pin as below.
* When COM Port is
Opened, DTR is High
* When COM Port is
Closed, DTR is Low
5
NC - - - - - -
This pin cannot be used
* There should be no
circuit connection.
Therefore, it should be
open at the External
Device.
6
GND - - - - - - -
Power- Supply and signal
ground.