// LED_Battery_Meter.c // Multisegment, multicolor LED voltage meter for 12 & 24 V SLA batteries // Written by Dale Wheat - 23 July 2008 // 30 jan 2009 - change EIN1D to AIN1D - header file was corrected // device = ATtiny13 // clock = 9.6 MHz internal RC oscillator // brown out detect level = 2.7 V // watchdog timer always on // input voltage divider = 10 Kohm + 1.8 Kohm resistors: ratio = 6-5/9:1, or 0.15254x // 31.24067797 ADC units per volt assuming 5.00 volt reference voltage #define VOLTS(v) (int)(v * 31.24067797) /////////////////////////////////////////////////////////////////////////////// #include #include #include #include #define nop() asm("nop") /////////////////////////////////////////////////////////////////////////////// // global variables /////////////////////////////////////////////////////////////////////////////// volatile union { struct { unsigned char red1:1; unsigned char red2:1; unsigned char red3:1; unsigned char red4:1; unsigned char red5:1; unsigned char red6:1; unsigned char green1:1; unsigned char green2:1; unsigned char green3:1; unsigned char green4:1; unsigned char green5:1; unsigned char green6:1; }; unsigned int value; } LEDs; /////////////////////////////////////////////////////////////////////////////// // initialization functions /////////////////////////////////////////////////////////////////////////////// // init() - initialize everything void init(void) __attribute__ ((naked)) __attribute__ ((section(".init3"))); void init(void) { // initialize ATtiny13 on-chip watchdog timer WDTCR = 1<>= 3; // 24.00 V 12.00 V // range range condition display // ------- ------- --------- ------------ // red flash warning // 30.00 V 15.00 V overvoltage // happy dance // 27.00 V 13.50 V charge // 6 green dots // 25.30 V 12.65 V 100% charge // 5 green dots // 24.90 V 12.45 V 75% // 4 green dots // 24.48 V 12.24 V 50% // 3 yellow dots // 24.12 V 12.06 V 25% // 2 red dots // 24.00 V 12.00 V flat // 1 red dot // 23.78 V 11.89 V discharged // 1 flashing red dot // 23.00 V 11.50 V crazy low // no dots at all if(voltage > VOLTS(30.0)) blink(0x02A, 0x015); // overvoltage for this meter // wig wag blink ("uh oh uh oh") // 24 V range else if(voltage > VOLTS(27.00)) happy_dance(); // charging // happy dance else if(voltage > VOLTS(25.30)) LEDs.value = 0xFC0; // 100% or more // 6 green dots else if(voltage > VOLTS(24.90)) LEDs.value = 0x7C0; // 75% or more // 5 green dots else if(voltage > VOLTS(24.48)) LEDs.value = 0x3C0; // 50% or more // 4 green dots else if(voltage > VOLTS(24.12)) LEDs.value = 0x1C7; // 25% or more // 3 yellow dots else if(voltage > VOLTS(24.00)) LEDs.value = 0x003; // flat // 2 red dots else if(voltage > VOLTS(23.78)) LEDs.value = 0x001; // discharged // 1 red dot else if(voltage > VOLTS(23.00)) blink(0x000, 0x001); // battery failure // blink one red dot else if(voltage > VOLTS(15.00)) LEDs.value = 0; // 23.00 V or less // no dots // 12 V range else if(voltage > VOLTS(13.50)) happy_dance(); // charging // happy dance else if(voltage > VOLTS(12.65)) LEDs.value = 0xFC0; // 100% or more // 6 green dots else if(voltage > VOLTS(12.45)) LEDs.value = 0x7C0; // 75% or more // 5 green dots else if(voltage > VOLTS(12.24)) LEDs.value = 0x3C0; // 50% or more // 4 green dots else if(voltage > VOLTS(12.06)) LEDs.value = 0x1C7; // 25% or more // 3 yellow dots else if(voltage > VOLTS(12.00)) LEDs.value = 0x003; // flat // 2 red dots else if(voltage > VOLTS(11.89)) LEDs.value = 0x001; // discharged // 1 red dot else if(voltage > VOLTS(11.50)) blink(0x000, 0x001); // battery failure // blink one red dot // calibration else if(voltage == VOLTS(7.50)) LEDs.value = 0x30C; // middle two LEDs red + green //else if((voltage <= VOLTS(7.50)) && (voltage >= VOLTS(7.40))) LEDs.value = 0x30C; // middle two LEDs red + green // or nothing else LEDs.value = 0; // 11.50 V or less // no dots for you voltage = 0; // reset voltage } } /////////////////////////////////////////////////////////////////////////////// // [end-of-file]