PIC programmer plug-inThe PIC programmer plug-in will allow a PIC16F8XX based expansion board that is hooked up to the Homevision controler's I2C bus to be reprogrammed without the need for a hardware PIC programmer. It isn't even necessary to powerdown or disconnect the device or remove the PIC from the device. All that is required is that the PIC is initially programmed with a program containing a self-programming routine. So if you don't have a hardware PIC programmer, you only have to bother a friend once to program it for you. Also some suppliers offer to initially program the PIC for you for a small fee when you buy it. The self-programming routine fits in less than 128 code words, taking up only 6% of the programming space of a PIC16F819 or 3% of a PIC16F88.
The plug-in currently supports the following PIC models:
Some of the mentioned PICs require blocks of 32 words to be erased before they can be reprogrammed. Also some PICs must be programmed in blocks of 4 words. This can be observed in the PIC programmer window. Below is an image of what the window might look like while programming a PIC16F819:
Legend of the used colors:
The PIC programmer plug-in has some limitations:
The plug-in keeps track of the individual settings of each expansion board, in case more than one self-programmable board is connected to the HomeVision expansion bus.
The self programming code has been used in the Mini MFEB project.