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scale_korona
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add weight measurement

This commit is contained in:
King Kévin 2015-01-08 10:00:56 +01:00
parent b30d73f3fa
commit 336d4e5bda
2 changed files with 60 additions and 11 deletions
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4
firmware/Makefile
View File

@ -10,6 +10,8 @@ OBJDUMP=avr-objdump
OBJCOPY=avr-objcopy
SIZE=avr-size
CFLAGS=-g -Wall -Werror -O3 -std=c99
# for this project we need float capable printf
LDFLAGS=-lm -Wl,-u,vfprintf -lprintf_flt
# the target (arduino nano)
DEVICE=atmega328p
F_CPU=16000000UL
@ -66,7 +68,7 @@ compile: $(TARGET).elf
# link compiled files
%.elf: $(OBJ)
$(CC) $(CFLAGS) -I. -mmcu=$(DEVICE) -DF_CPU=$(F_CPU) -Wl,-Map=$(TARGET).map,--cref -o $@ $(OBJ)
$(CC) $(LDFLAGS) -I. -mmcu=$(DEVICE) -DF_CPU=$(F_CPU) -Wl,-Map=$(TARGET).map,--cref -o $@ $(OBJ)
# create extended listing for additional information
%.lst: %.elf

67
firmware/main.c
View File

@ -25,16 +25,24 @@
#include <avr/pgmspace.h> // Program Space Utilities
#include <avr/sleep.h> // Power Management and Sleep Modes
#include "uart.h" // basic UART functions
#include "main.h" // main definitions
/* contants */
// max measurement jitter for high and low value
#define JITTER_HIGH 8
#define JITTER_LOW 3
// how many value have to be stable before showing output
#define MEASUREMENT_STABLE 3
// weight coefficient (timer 1 ticks/kg)
// proportionally decreasing for high, increasing for low
#define COEF_HIGH 41.78
#define COEF_LOW 39.87
/* variables */
volatile uint8_t state_portD; // the state of port D
volatile bool scale_on = false; // is the scale on (based on the SCALE_ON PIN)
#ifdef DEBUG
volatile bool scale_old = false; // the previous state (to detect changes)
#endif
volatile bool pwm_high = false; // is the PWM for the weight measurement high
volatile bool measurement_flag = false; // is a PWM measurement value ready
volatile uint16_t measurement_value = 0; // the PWM measurement value from the timer
@ -144,37 +152,76 @@ void io_init(void)
int main(void)
{
uint16_t measurement_high = 0, measurement_low = 0; // the average measurement value
uint16_t zero_high = 0, zero_low = 0; // the intial zero value
uint8_t count_high = 0, count_low = 0; // the number of stable counts
io_init(); // initialize IOs
printf(PSTR("welcome to the body scale weight reader\n")); // print welcome message
while (true) { // endless loop for micro-controller
#ifdef DEBUG
/* display if scale switches on */
if (scale_old!=scale_on && scale_on) {
#ifdef DEBUG
printf(PSTR("scale start\n"));
scale_old=scale_on;
}
#endif
measurement_high = measurement_low = zero_high = zero_low = count_high = count_low = 0; // re-initialize values
scale_old = scale_on; // save new state
}
/* display value if available */
if (measurement_flag) {
if (pwm_high) {
#ifdef DEBUG
printf("high: %u\n",measurement_value);
printf("high: %u\n", measurement_value);
#endif
if (measurement_value<=measurement_high+JITTER_HIGH && measurement_value>=measurement_high-JITTER_HIGH) { // stable value
measurement_high = (measurement_high+measurement_value)/2;
count_high += 1;
} else {
measurement_high = measurement_value;
count_high = 0;
}
} else {
#ifdef DEBUG
printf("low: %u\n",measurement_value);
printf("low: %u\n", measurement_value);
#endif
if (measurement_value<=measurement_low+JITTER_LOW && measurement_value>=measurement_low-JITTER_LOW) { // stable value
measurement_low = (measurement_low+measurement_value)/2;
count_low += 1;
} else {
measurement_low = measurement_value;
count_low = 0;
}
}
#ifdef DEBUG
printf("values high/low (stable): %u (%u)/%u (%u)\n", measurement_high, count_high, measurement_low, count_low);
#endif
measurement_flag = false;
}
/* display weight if values are stable */
if (count_high>=MEASUREMENT_STABLE && count_low>=MEASUREMENT_STABLE) {
if (zero_high == 0 && zero_low == 0) { // initialize zero values
zero_high = measurement_high;
zero_low = measurement_low;
#ifdef DEBUG
printf("zero values high/low: %u/%u\n", zero_high, zero_low);
#endif
} else { // prinf measurement weight
double weight_high = (int16_t)(zero_high-measurement_high)/COEF_HIGH;
double weight_low = (int16_t)(measurement_low-zero_low)/COEF_LOW;
double weight = (weight_high+weight_low)/2;
printf("%d kg\n", zero_high-measurement_high);
printf("%.2f kg\n", weight);
}
count_high = count_low = 0;
}
/* display if scale switches off */
if (scale_old!=scale_on && !scale_on) {
#ifdef DEBUG
printf(PSTR("scale stop\n"));
scale_old=scale_on;
}
#endif
scale_old = scale_on; // save new state
}
/* go to sleep and wait for next interrupt */
set_sleep_mode(SLEEP_MODE_IDLE);
sleep_mode();