working version

Makefile

@@ -1,6 +1,6 @@
 PRG            = blmc
 OBJ            = blmc.o eeprom.o i2c-slave.o main.o
-MCU_TARGET     = atmega8
+MCU_TARGET     = atmega88
 OPTIMIZE       = -Os
 
 DEFS           =
@@ -61,4 +61,4 @@ ebin:  $(PRG)_eeprom.bin
 
 install: text
 #	uisp -dprog=avr910 -dserial=/dev/ttyS0 -dspeed=115200 -dpart=M8 --erase --upload if=$(PRG).hex
-	avrdude -p m8 -c butterfly -b 115200 -P /dev/ttyUSB1 -u -e -V -U flash:w:$(PRG).hex
+	avrdude -p m88 -c butterfly -b 115200 -u -e -V -U flash:w:$(PRG).hex

README

@@ -1,8 +1,11 @@
-blmc v1
+blmc v2
 =======
 
-An AVR mega8 based brushless motor controller.
-- SW/HW and i2c protocol are *NOT* compatible with H+I blctrl!
+An AVR mega88/168 based brushless motor controller.
 - must run with TWIBOOT as bootloader to get own i2c address
 - spinup parameters in EEPROM
 - extended i2c protocol
+
+TODO:
+- remove C1/C3/C6 and do "timed" commutation
+- replace C11 with smaller value / remove it

blmc.c

@@ -31,67 +31,86 @@ static uint8_t next_sense;
 
 void trigger_adc(uint8_t channel)
 {
-	/* Disable Analog Comperator */
-	ACSR &= ~(1<<ACIE);
+	/* Disable Analog Comperator Interrupt */
+	TIMSK1 &= ~(1<<ICIE1);
 
-	/* set channel (Internal reference, 2.56V) */
-	ADMUX = (1<<REFS1) | (1<<REFS0) | channel;
+	/* set channel (external reference, 5V) */
+	ADMUX = (0<<REFS1) | (0<<REFS0) | channel;
 
-	/* turn on ADC with interrupts, start conversion with 1/32 of F_CPU */
-	ADCSRA = (1<<ADEN) | (1<<ADSC) | (1<<ADIE) | (1<<ADIF)| (1<<ADPS2) | (1<<ADPS0);
+	/*
+	 * turn on ADC with interrupts
+	 * start conversion with 1/32 of F_CPU
+	 * 1/250kHz * 25 => 100us conversion time
+	 */
+	ADCSRA = (1<<ADEN) | (1<<ADSC) | (1<<ADIE) | (1<<ADIF)| (1<<ADPS2) | (0<<ADPS0);
 }
 
-void next_phase(void)
+static void next_phase(void)
 {
 	static uint8_t phase;
 	static uint8_t phase_adc;
 
-	/* Disable Analog Comperator */
-	ACSR &= ~(1<<ACIE);
-
-	TCNT1 = 0x00;
-	TCNT2 = 0x00;
+	/* Disable Analog Comperator Interrupt */
+	TIMSK1 &= ~(1<<ICIE1);
 
 	switch (phase) {
-	case 0:	PORTD = (PORTD & ~PHASE_L_MASK) | PHASE_B_L;
-		TCCR1A = (TCCR1A & ~(1<<COM1B1)) | (1<<COM1A1);
-		TCCR2 &= ~(1<<COM21);
-		ACSR = (1<<ACIS1);
+	case 0: /* A: PWM, B: LOW, C: SENSE => disable EN_C, disable PWM_B, enable EN_B */
+		PORTD &= ~PHASE_C_EN;
+		TCCR0A &= ~PHASE_B_OC;
+		PORTD |= PHASE_B_EN;
+
+		/* C: falling edge */
+		TCCR1B &= ~(1<<ICES1);
 		next_sense = SENSE_C;
 		break;
 
-	case 1:	PORTD = (PORTD & ~PHASE_L_MASK) | PHASE_B_L;
-		TCCR1A &= ~((1<<COM1A1) | (1<<COM1B1));
-		TCCR2 |= (1<<COM21);
-		ACSR = (1<<ACIS1) | (1<<ACIS0);
+	case 1: /* A: SENSE, B: LOW, C: PWM => disable EN_A, enable PWM_C, enable EN_C */
+		PORTB &= ~PHASE_A_EN;
+		TCCR2A |= PHASE_C_OC;
+		PORTD |= PHASE_C_EN;
+
+		/* A: rising edge */
+		TCCR1B |= (1<<ICES1);
 		next_sense = SENSE_A;
 		break;
 
-	case 2:	PORTD = (PORTD & ~PHASE_L_MASK) | PHASE_A_L;
-		TCCR1A &= ~((1<<COM1A1) | (1<<COM1B1));
-		TCCR2 |= (1<<COM21);
-		ACSR = (1<<ACIS1);
+	case 2: /* A: LOW, B: SENSE, C: PWM => disable EN_B, disable PWM_A, enable EN_A */
+		PORTD &= ~PHASE_B_EN;
+		TCCR2A &= ~PHASE_A_OC;
+		PORTB |= PHASE_A_EN;
+
+		/* B: falling edge */
+		TCCR1B &= ~(1<<ICES1);
 		next_sense = SENSE_B;
 		break;
 
-	case 3:	PORTD = (PORTD & ~PHASE_L_MASK) | PHASE_A_L;
-		TCCR1A = (TCCR1A & ~(1<<COM1A1)) | (1<<COM1B1);
-		TCCR2 &= ~(1<<COM21);
-		ACSR = (1<<ACIS1) | (1<<ACIS0);
+	case 3: /* A: LOW, B: PWM, C: SENSE => disable EN_C, enable PWM_B, enable EN_B */
+		PORTD &= ~PHASE_C_EN;
+		TCCR0A |= PHASE_B_OC;
+		PORTD |= PHASE_B_EN;
+
+		/* C: rising edge */
+		TCCR1B |= (1<<ICES1);
 		next_sense = SENSE_C;
 		break;
 
-	case 4:	PORTD = (PORTD & ~PHASE_L_MASK) | PHASE_C_L;
-		TCCR1A = (TCCR1A & ~(1<<COM1A1)) | (1<<COM1B1);
-		TCCR2 &= ~(1<<COM21);
-		ACSR = (1<<ACIS1);
+	case 4: /* A: SENSE, B: PWM, C: LOW => disable EN_A, disable PWM_C, enable EN_C */
+		PORTB &= ~PHASE_A_EN;
+		TCCR2A &= ~PHASE_C_OC;
+		PORTD |= PHASE_C_EN;
+
+		/* A: falling edge */
+		TCCR1B &= ~(1<<ICES1);
 		next_sense = SENSE_A;
 		break;
 
-	case 5:	PORTD = (PORTD & ~PHASE_L_MASK) | PHASE_C_L;
-		TCCR1A = (TCCR1A & ~(1<<COM1B1)) | (1<<COM1A1);
-		TCCR2 &= ~(1<<COM21);
-		ACSR = (1<<ACIS1) | (1<<ACIS0);
+	case 5: /* A: PWM, B: SENSE, C: LOW => disable EN_B, enable PWM_A, enable EN_A */
+		PORTD &= ~PHASE_B_EN;
+		TCCR2A |= PHASE_A_OC;
+		PORTB |= PHASE_A_EN;
+
+		/* B: rising edge */
+		TCCR1B |= (1<<ICES1);
 		next_sense = SENSE_B;
 		break;
 	}
@@ -114,8 +133,10 @@ void next_phase(void)
 		ADMUX = next_sense;
 
 		/* enable Analog Comparator with Interrupts */
-		if (blmc.flags & FLAG_COM_NORMAL)
-			ACSR |= (1<<ACIE) | (1<<ACI);
+		if (blmc.flags & FLAG_COM_NORMAL) {
+			TIFR1 |= (1<<ICF1);
+			TIMSK1 |= (1<<ICIE1);
+		}
 	}
 
 	phase++;
@@ -207,12 +228,21 @@ void setpwm(uint8_t pwm)
 	if (pwm > params.pwm_max)
 		pwm = params.pwm_max;
 
-	OCR1A = pwm;
-	OCR1B = pwm;
-	OCR2 = pwm;
+	OCR0B = pwm;
+	OCR2A = pwm;
+	OCR2B = pwm;
+
+	/* disable PWM signales, enable all drivers -> brake */
+	if (pwm == 0) {
+		TCCR0A &= ~PHASE_B_OC;
+		TCCR2A &= ~(PHASE_A_OC | PHASE_C_OC);
+
+		PORTB |= PHASE_A_EN;
+		PORTD |= (PHASE_B_EN | PHASE_C_EN);
+	}
 }
 
-ISR(ANA_COMP_vect)
+ISR(TIMER1_CAPT_vect)
 {
 	next_phase();
 }
@@ -232,8 +262,10 @@ ISR(ADC_vect)
 	ADCSRA = 0x00;
 
 	/* enable Analog Comparator with Interrupts */
-	if (blmc.flags & FLAG_COM_NORMAL)
-		ACSR |= (1<<ACIE) | (1<<ACI);
+	if (blmc.flags & FLAG_COM_NORMAL) {
+		TIFR1 |= (1<<ICF1);
+		TIMSK1 |= (1<<ICIE1);
+	}
 
 	if (channel == SENSE_CURRENT) {
 		current_tmp += value;

blmc.h

@@ -1,6 +1,8 @@
 #ifndef _BLMC_H_
 #define _BLMC_H_
 
+#include <avr/io.h>
+
 #define FLAG_RUN_MASK			0x00F
 #define FLAG_PWM_SPINUP			0x001
 #define FLAG_PWM_NORMAL			0x002

eeprom.c

@@ -16,11 +16,12 @@
  *   Free Software Foundation, Inc.,                                       *
  *   59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.             *
  ***************************************************************************/
+#include <avr/pgmspace.h>
 #include <avr/eeprom.h>
 #include <util/crc16.h>
 #include "eeprom.h"
 
-static const struct ee_param defaults = DEFAULT_PARAMETERS;
+static struct ee_param defaults PROGMEM = DEFAULT_PARAMETERS;
 
 struct ee_param params;
 struct ee_param params_in_eeprom EEMEM = DEFAULT_PARAMETERS;
@@ -48,12 +49,7 @@ uint8_t read_parameters(void)
 		crc = _crc_ccitt_update(crc, *tmp++);
 
 	if (crc != 0x0000) {
-		i = sizeof(struct ee_param);
-		uint8_t *src = (uint8_t *)&defaults;
-		uint8_t *dst = (uint8_t *)&params;
-		while (i--)
-			*dst++ = *src++;
-
+		memcpy_P(&params, &defaults, sizeof(struct ee_param));
 		write_parameters();
 		return 1;
 	}

eeprom.h

@@ -22,16 +22,17 @@ struct ee_param {
 };
 
 #define DEFAULT_PARAMETERS { \
-	.spinup_ticks = 1000, \
-	.spinup_tick = 25, \
-	.spinup_step = 24, \
+	.spinup_ticks = 2000, \
+	.spinup_tick = 24, \
+	.spinup_step = 4, \
 	.spinup_wait = 10, \
-	.spinup_pwm = 0x0f, \
+	.spinup_pwm = 25, \
 	.pwm_min = 0x08, \
 	.pwm_max = 0xff, \
 	.current_limit = 120, \
 	.current_max = 0x3ff, \
 	.voltage_min = 0x000, \
+	.crc16 = 0xDB76, \
 };
 
 uint8_t read_parameters(void);

i2c-slave.c

@@ -61,20 +61,19 @@ extern struct ee_param params;
 
 
 
-const static uint8_t info[16] = "blmc m8-v1.2   ";
+const static uint8_t info[16] = "blctrl m88-v2.0";
 
 ISR(TWI_vect)
 {
 	static uint8_t cmd;
 	static uint8_t bcnt;
 	uint8_t data;
-	uint8_t ack = (1<<TWEA);
 
 	switch (TWSR & 0xF8) {
 	/* SLA + W received, ACK returned -> receive Data and ACK */
 	case 0x60:
 		bcnt = 0;
-		TWCR |= (1<<TWINT) | (1<<TWEA);
+		TWCR = (1<<TWEN) | (1<<TWIE) | (1<<TWINT) | (1<<TWEA);
 		break;
 
 	/* prev. SLA + W, data received, ACK returned -> receive Data and ACK */
@@ -103,9 +102,6 @@ ISR(TWI_vect)
 			case CMD_SWITCH_APPLICATION:
 				if (data == BOOTTYPE_BOOTLOADER) {
 					wdt_enable(WDTO_15MS);
-
-				} else {
-					ack = (0<<TWEA);
 				}
 				break;
 
@@ -113,14 +109,10 @@ ISR(TWI_vect)
 				bcnt++;
 				if (data == MEMTYPE_PARAMETERS) {
 					cmd = CMD_WRITE_PARAMETERS;
-
-				} else {
-					ack = (0<<TWEA);
 				}
 				break;
 
 			default:
-				ack = (0<<TWEA);
 				break;
 			}
 			break;
@@ -136,21 +128,16 @@ ISR(TWI_vect)
 				((uint8_t *)&params)[bcnt++ -4] = data;
 				if (bcnt == sizeof(params)) {
 					write_parameters();
-					ack = (0<<TWEA);
 				}
 				break;
 
 			default:
-				ack = (0<<TWEA);
 				break;
 			}
 			break;
 		}
 
-		if (ack == 0x00)
-			bcnt = 0;
-
-		TWCR |= (1<<TWINT) | ack;
+		TWCR = (1<<TWEN) | (1<<TWIE) | (1<<TWINT) | (1<<TWEA);
 		break;
 
 	/* SLA+R received, ACK returned -> send data */
@@ -161,16 +148,32 @@ ISR(TWI_vect)
 		switch (cmd) {
 		case CMD_WAIT:
 			switch (bcnt++) {
-			case 0:
-				data = blmc.current & 0xFF;
+			case 0: data = blmc.pwm - blmc.pwm_limit;
 				break;
 
-			case 1:
-				data = 0xFF - blmc.pwm_limit;
+			case 1: data = blmc.pwm;
+				break;
+
+			case 2: data = (blmc.rpm & 0xFF);
+				break;
+
+			case 3: data = (blmc.rpm >> 8);
+				break;
+
+			case 4: data = (blmc.current & 0xFF);
+				break;
+
+			case 5: data = (blmc.current >> 8);
+				break;
+
+			case 6: data = (blmc.voltage & 0xFF);
+				break;
+
+			case 7: data = (blmc.voltage >> 8);
 				break;
 
 			default:
-				data = 0xFF;
+				data = 0x00;
 				break;
 			}
 			break;
@@ -192,19 +195,19 @@ ISR(TWI_vect)
 		}
 
 		TWDR = data;
-		TWCR |= (1<<TWINT) | (1<<TWEA);
+		TWCR = (1<<TWEN) | (1<<TWIE) | (1<<TWINT) | (1<<TWEA);
 		break;
 
 	/* STOP or repeated START */
 	case 0xA0:
 	/* Data transmitted, NACK returned */
 	case 0xC0:
-		TWCR |= (1<<TWINT) | (1<<TWEA);
+		TWCR = (1<<TWEN) | (1<<TWIE) | (1<<TWINT) | (1<<TWEA);
 		break;
 
 	/* failsave -> reset Hardware */
 	default:
-		TWCR |= (1<<TWINT) | (1<<TWSTO) | (1<<TWEA);
+		TWCR = (1<<TWEN) | (1<<TWIE) | (1<<TWINT) | (1<<TWSTO) | (1<<TWEA);
 		break;
 	}
 }

main.c

@@ -46,13 +46,13 @@ extern struct blmc_ blmc;
 
 static uint8_t led[2];
 
-ISR(TIMER0_OVF_vect)
+ISR(TIMER1_COMPB_vect)
 {
-	static uint8_t timer0_cnt = 0;
+	static uint8_t rpm_cnt = 0;
 	static uint8_t adc_chan = SENSE_CURRENT;
 
 	/* Come back in 20ms */
-	TCNT0 = 0xFF - 156;
+	OCR1B = TCNT1 + 20000;
 
 	/* commutations during last 20ms */
 	uint16_t diff = blmc.rpm_tmp - blmc.rpm_tmp_old;
@@ -64,7 +64,7 @@ ISR(TIMER0_OVF_vect)
 			blmc.flags &= ~(FLAG_RUN_MASK);
 			blmc.flags |= FLAG_PWM_SPINUP | FLAG_COM_SPINUP;
 		}
-
+#if 0
 		/* no i2c cmd in the last 20ms */
 		if (!(blmc.flags & FLAG_I2C_ACTIVE)) {
 			/* already in i2c timeout, turn off motor */
@@ -76,7 +76,7 @@ ISR(TIMER0_OVF_vect)
 		} else {
 			blmc.flags &= ~FLAG_I2C_TIMEOUT;
 		}
-
+#endif
 		blmc.flags &= ~FLAG_I2C_ACTIVE;
 	}
 
@@ -84,9 +84,9 @@ ISR(TIMER0_OVF_vect)
 	setpwm(blmc.pwm);
 
 	/* calc rpm every second */
-	timer0_cnt++;
-	if (timer0_cnt == 50) {
-		timer0_cnt = 0;
+	rpm_cnt++;
+	if (rpm_cnt == 50) {
+		rpm_cnt = 0;
 
 		blmc.rpm = blmc.rpm_tmp;
 		blmc.rpm_tmp = 0;
@@ -100,7 +100,6 @@ ISR(TIMER0_OVF_vect)
 		else
 			adc_chan = SENSE_CURRENT;
 	}
-
 	/* led blink timer */
 	static uint8_t led_timer = 0;
 	led_timer = (led_timer +1) & 0x1F;
@@ -126,29 +125,49 @@ ISR(TIMER0_OVF_vect)
 	}
 }
 
+/*
+ * For newer devices (mega88) the watchdog timer remains active even after a
+ * system reset. So disable it as soon as possible.
+ * automagically called on startup
+ */
+void get_mcusr(void) __attribute__((naked, section(".init3")));
+void get_mcusr(void)
+{
+	MCUSR = 0;
+	WDTCSR = (1<<WDCE) | (0<<WDE);
+}
+
 int main(void)
 {
-	DDRB = PHASE_H_MASK | LED_RT | LED_GN;
-	DDRD = PHASE_L_MASK;
+	DDRB = PHASE_A_EN | PHASE_A_PWM | LED_RT | LED_GN;
+	DDRD = PHASE_B_EN | PHASE_B_PWM | PHASE_C_EN | PHASE_C_PWM;
 
 	PORTB = 0x00;
 	PORTD = 0x00;
 
-	/* timer0: running with F_CPU/1024 */
-	TCCR0 = (1<<CS02) | (1<<CS00);
+	/* timer0: running with F_CPU, 8bit Phase Correct PWM (16kHz) */
+	TCCR0A = (1<<WGM00);
+	TCCR0B = (1<<CS00);
 
-	/* timer1: running with F_CPU, 8bit Phase Correct PWM (16kHz) */
-	TCCR1B = (1<<CS10);
-	TCCR1A = (1<<WGM10);
+	/* timer1: running with F_CPU/8 */
+	TCCR1B = (1<<CS11) | (1<<ICNC1);
 
 	/* timer2: running with F_CPU, 8bit Phase Correct PWM (16kHz) */
-	TCCR2 = (1<<WGM20) | (1<<CS20);
+	TCCR2A = (1<<WGM20);
+	TCCR2B = (1<<CS20);
 
-	/* enable Timer0 OVF Interrupt */
-	TIMSK = (1<<TOIE0);
+	/* sync PWM timers */
+	GTCCR = (1<<TSM) | (1<<PSRASY) | (1<<PSRSYNC);
+	TCNT0 = 0x00;
+	TCNT2 = 0x00;
+	GTCCR = (0<<TSM);
+
+	/* enable Timer1 OVF Interrupt */
+	TIMSK1 = (1<<OCIE1B);
 
 	/* Enable Analog Comparator Multiplexer */
-	SFIOR |= (1<<ACME);
+	ADCSRB |= (1<<ACME);
+	ACSR |= (1<<ACIC);
 
 	/* I2C Init: keep Address from bootloader, Auto ACKs with Interrupts */
 	TWCR = (1<<TWEA) | (1<<TWEN) | (1<<TWIE);
@@ -210,5 +229,6 @@ int main(void)
 
 		sleep_mode();
 	};
+
 	return 0;
 }

main.h

@@ -9,21 +9,23 @@
 #define LED_RT		(1<<PORTB4)
 #define LED_GN		(1<<PORTB5)
 
-#define PHASE_A_H	(1<<PORTB1)
-#define PHASE_B_H	(1<<PORTB2)
-#define PHASE_C_H	(1<<PORTB3)
-#define PHASE_H_MASK	(PHASE_A_H | PHASE_B_H | PHASE_C_H)
+#define PHASE_A_EN	(1<<PORTB2)
+#define PHASE_A_PWM	(1<<PORTB3)
+#define PHASE_A_OC	(1<<COM2A1)
 
-#define PHASE_A_L	(1<<PORTD4)
-#define PHASE_B_L	(1<<PORTD3)
-#define PHASE_C_L	(1<<PORTD2)
-#define PHASE_L_MASK	(PHASE_A_L | PHASE_B_L | PHASE_C_L)
+#define PHASE_B_EN	(1<<PORTD7)
+#define PHASE_B_PWM	(1<<PORTD5)
+#define PHASE_B_OC	(1<<COM0B1)
+
+#define PHASE_C_EN	(1<<PORTD4)
+#define PHASE_C_PWM	(1<<PORTD3)
+#define PHASE_C_OC	(1<<COM2B1)
 
 #define SENSE_A		0
-#define SENSE_B		1
-#define SENSE_C		2
+#define SENSE_B		2
+#define SENSE_C		1
 
-#define SENSE_VOLTAGE	3
-#define SENSE_CURRENT	6
+#define SENSE_VOLTAGE	7
+#define SENSE_CURRENT	3
 
 #endif