Patent attributes
A power tool system component has a microprocessor, a one wire communication terminal connecting the microprocessor to an external device, and a flash memory storing: (a) an application program governing operation of an application mode during which the power tool system component is operated; and (b) a boot loader program governing operation of a boot loader mode during which at least part of the application program can be updated. The microprocessor accesses the flash memory and implements the boot loader program and the application program by setting up and observing a temporal window during which one or more predetermined conditions must be met for the boot loader mode to be entered. The predetermined conditions include successful completion of a calibration process that includes sending a calibration byte to the external device according to a format predetermined to allow the external device to adjust its baud rate for sending and receiving information. Upon successful completion of the conditions within the temporal window, the microprocessor sends a confirmation to the device that the conditions have been satisfied and enters the boot loader mode.
