Here is what I observed:
-
if you plug a wall charger then unit stop logging and start charging.
-
if you plug it to PC then the SD card dirver show on PC, stop logging.
I am new to ARM programming, anyone know which function it called after plug USB in?
Thanks!
have a look at the usb boot loader source code.
if(IOPIN0 & (1<<23)) //Check to see if the USB cable is plugged in
{
main_msc(); //If so, run the USB device driver.
}
it is checking whether the P0.23 pin is set high or not.
if you have a look at the schematic the net name is “USB_VBUS_DT”
probably this pin is not set hence your program will not proceeed and wont log anything…