Interrupt Service Routine (continued)

• //------------------------------------------------
• // reset temp's for next pair of 60hz cycles
• //------------------------------------------------
• tick20Count = 0;
• max_sample = 0;
• min_sample = 0;
• Intermediate2 = 8192;
• Intermediate1 = 8192;
• metric = 0;
• //------------------------------------------------
• // advance breaker number, mod ADC_CHANNELS
• //------------------------------------------------
• breakerNumber++;
• if (breakerNumber >= ADC_CHANNELS)
• breakerNumber = 0;
• //------------------------------------------------
• // output transducer board address,
• // and select PIC ADC input for next 60hz cycle
• //------------------------------------------------
• ADCON1 = 0x0B;
• TRISF = 0x00;
• LATF = ((breakerNumber&0x3C)<<2) | ((breakerNumber&0x3C)>>2);
• ADCON0 &= ~0x3C;
• ADCON0 |= (breakerNumber&&0x03)<< 2;
• }

• Restore temp variables to starting values for next input measurement

• Step to the next breaker number,
• modulo ADC_CHANNELS

• The least significant 2 bits of breaker address will select which of the 4 analog inputs to A/D sample.
• The next 4 bits of breaker address are written to PIC outputs to select interface board, and one of the 4016 chips on that interface board