sumorobot-firmware/hal.py

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Python
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2017-12-17 13:59:52 +00:00
from utime import sleep_us
from machine import Pin, PWM, ADC, time_pulse_us
WIFIS = dict({
"": ""})
# directions
STOP = 0
LEFT = 1
RIGHT = 2
FORWARD = 3
BACKWARD = 4
# Battery resistor ladder ratio
BATTERY_COEFF = 2.25
# Ultrasonic sensor calibration
ULTRASONIC_OFFSET = 800
# Servo timing
MOTOR_LEFT_TUNING = 33
MOTOR_RIGHT_TUNING = 33
# Ultrasonic distance sensor
echo = Pin(14, Pin.IN)
trigger = Pin(27, Pin.OUT)
# Motor PWM-s
pwm_left = PWM(Pin(15), freq=50, duty=0)
pwm_right = PWM(Pin(4), freq=50, duty=0)
# bottom LED
bottom_led = Pin(5, Pin.OUT)
# bottom LED is in reverse polarity
bottom_led.value(1)
# sensor LEDs
enemy_led = PWM(Pin(16), freq=50, duty=0)
left_line_led = PWM(Pin(17), freq=50, duty=0)
right_line_led = PWM(Pin(12), freq=50, duty=0)
# Battery gauge
adc_battery = ADC(Pin(32))
# Optek sensors
adc_line_left = ADC(Pin(34))
adc_line_right = ADC(Pin(33))
# Set reference voltage to 3.3V
adc_battery.atten(ADC.ATTN_11DB)
adc_line_left.atten(ADC.ATTN_11DB)
adc_line_right.atten(ADC.ATTN_11DB)
# Calibrate line sensors
LINE_LEFT_THRESHOLD = adc_line_left.read()
LINE_RIGHT_THRESHOLD = adc_line_right.read()
def status_led(state):
bottom_led.value(0 if state else 1)
def battery_voltage():
return BATTERY_COEFF * (adc_battery.read() * 3.3 / 4096)
enemy_score = 0
def enemy_distance():
global enemy_score
trigger.value(0)
sleep_us(5)
trigger.value(1)
sleep_us(10)
trigger.value(0)
# wait for the pulse and calculate the distance
enemy_distance = (machine.time_pulse_us(echo, 1, 30000) / 2) / 29.1
if enemy_distance < 60 and enemy_distance > 0:
if enemy_score < 5:
enemy_score += 1
else:
if enemy_score > 0:
enemy_score -= 1
# indicate enemy LED
enemy_led.duty(255 if enemy_score > 2 else 0)
return True if enemy_score > 2 else False
def line_left():
line = abs(adc_line_left.read() - LINE_LEFT_THRESHOLD) > 1000
if line:
left_line_led.duty(255)
else:
left_line_led.duty(0)
return line
def line_right():
line = abs(adc_line_right.read() - LINE_RIGHT_THRESHOLD) > 1000
if line:
right_line_led.duty(255)
else:
right_line_led.duty(0)
return line
def detach_servos():
motor_left(0)
motor_right(0)
prev_left_speed = 0
def motor_left(speed):
global prev_left_speed
if speed == prev_left_speed:
return
prev_left_speed = speed
assert speed >= -100
assert speed <= 100
pwm_left.duty(int(33 + MOTOR_LEFT_TUNING + speed * 33 / 100)) # -100 ... 100 to 33 .. 102
if speed == 0:
pwm_left.duty(0)
prev_right_speed = 0
def motor_right(speed):
global prev_right_speed
if speed == prev_right_speed:
return
prev_right_speed = speed
assert speed >= -100
assert speed <= 100
pwm_right.duty(int(33 + MOTOR_RIGHT_TUNING + speed * 33 / 100)) # -100 ... 100 to 33 .. 102
if speed == 0:
pwm_right.duty(0)
print("Battery voltage: %.2fV" % battery_voltage())
print("Line sensor thresholds:", LINE_LEFT_THRESHOLD, LINE_RIGHT_THRESHOLD)