Sense Hat % Humididty reads erroneously high?
Posted: Mon Aug 13, 2018 1:09 pm
I have two Sense Hats here that read too high a value for the % Humidity. Environment Canada lists it at 75%. My on the wall mechanical meter reads 70%. My BME680 reads it at 63%. My sense hat reads it at 86%. Swapped Sense Hats and it reads 88%. The higher the humidity is the bigger the error is. They quit often read above 100% when the actual humidity is around 80% to 90%.
Just redid my SD Card with the latest Raspbian and same deal. They read on the high side of what the actual humidity is. Any suggestions?
Is there a newer firmware for the sense hat, and can they be flashed?
Just redid my SD Card with the latest Raspbian and same deal. They read on the high side of what the actual humidity is. Any suggestions?
Is there a newer firmware for the sense hat, and can they be flashed?
Code: Select all
import os
import time, datetime
from sense_hat import SenseHat, ACTION_PRESSED, ACTION_HELD, ACTION_RELEASED
sense = SenseHat()
sense.set_rotation(180)
sense.set_imu_config(False, False, False)
sense.low_light = True
s=(0.065) # scroll speed
w=(0) # color all white toggle
o=(140)
x=(2) #shutdown variable
# is really stick down
def pushed_up(event):
if event.action == ACTION_PRESSED:
sense.low_light = True
# is really stick up
def pushed_down(event):
if event.action == ACTION_PRESSED:
sense.low_light = False
#is really stick right
def pushed_left(event):
global w
global o
if event.action == ACTION_PRESSED:
w = (255)
o = (255)
# is really stick left
def pushed_right(event):
global w
global o
if event.action == ACTION_PRESSED:
w = (0)
o = (140)
def pushed_middle(event):
global x
if event.action == ACTION_PRESSED:
x = (0)
sense.stick.direction_up = pushed_up
sense.stick.direction_down = pushed_down
sense.stick.direction_left = pushed_left
sense.stick.direction_right = pushed_right
sense.stick.direction_middle = pushed_middle
while True:
dateString = "%A %B %-d %-I:%M:%p"
msg = "It is %s" % (datetime.datetime.now().strftime(dateString))
sense.show_message(msg, scroll_speed=s, text_colour=(w, 255, 255))
t = sense.get_temperature()
t = round(t)
if t <= 0:
tc = [w, w, 255] # Blue
elif t > 0 and t < 13:
tc = [255, 255, w] # Yellow
elif t >= 13 and t <= 25:
tc = [w, 255, w] # Green
elif t > 25 and t <30:
tc = [255, o, w] # Orange
elif t >= 30:
tc = [255, w, w] # Red
msg = "and %sc" % (t)
sense.show_message(msg, scroll_speed=s, text_colour=tc)
h = sense.get_humidity()
h = round(h)
if h < 0:
h = 0
if h > 100:
h = 100
if h < 30:
hc = [255, w, w] # Red
elif h >= 30 and h <= 60:
hc = [w, 255, w] # Green
elif h > 60 and h < 80:
hc = [255, 255, w] # Yellow
elif h >= 80:
hc = [255, w, w] # Red
msg = "with %s%% Humidity" % (h)
sense.show_message(msg, scroll_speed=s, text_colour=hc)
p = sense.get_pressure()
p = round(p)
if p > 0 and p < 982:
pc = [255, w, w] # Red
msg = "- Barometer is Very Low @ %smb - Storm Watch" % (p)
sense.show_message(msg, scroll_speed=s, text_colour=pc)
elif p >= 982 and p < 1004:
pc = [255, 255, w] # Yellow
msg = "- Barometer is Low @ %smb - Possible Percipitation" % (p)
sense.show_message(msg, scroll_speed=s, text_colour=pc)
elif p >= 1004 and p < 1026:
pc = [w, 255, w] # Green
msg = "- Barometer is Mid Range @ %smb" % (p)
sense.show_message(msg, scroll_speed=s, text_colour=pc)
elif p >= 1026 and p < 1048:
pc = [w, w, 255] # Blue
msg = "- Barometer is High @ %smb" % (p)
sense.show_message(msg, scroll_speed=s, text_colour=pc)
elif p >= 1048:
pc = [255, w, w] # Red
msg = "- Barometer is Very High @ %smb - Expect Dry Conditions" % (p)
sense.show_message(msg, scroll_speed=s, text_colour=pc)
if x == 0:
sense.clear()
os.system("sudo shutdown now -P")
time.sleep(30)
elif x == 1:
sense.clear()
raise SystemExit
time.sleep(30)
# Last edited on Aug 10th 2018
# run sudo crontab -e
# add
# @reboot python3 /home/pi/THP.py &
