Micropython - SHT30 in BTC Base

kedulowt

If someone would try work with SHT30, I recommend:

https://github.com/rsc1975/micropython-sht30

but in this base you should propertly sel scl, sda pins and i2c addres SHT30 is 0x44.

Code:
from sht30 import SHT30
sht30_sensor = SHT30(scl_pin=22, sda_pin=21, delta_temp=-3, i2c_address=0x44)
temperature, humidity = sht30_sensor.measure()

Also what i noticed that is showed temperature is higher than real. To correct it i use delta_temp.

TitiMoby

It is a bit too early because MicroPython is still not there on M5Paper that I own, but as it uses the same SHT30, I also noticed some delta issue in temperature using Arduino.
Is it a common thing with this component ?

sj3fk3

I honestly don't understand M5Stack's way of working. There is this ENV2 with python support: https://docs.m5stack.com/#/en/unit/envII it has a SHT30, but then you spend $80 on a M5Paper and you don't get python support for the SHT30. How hard is it to put in the the right lib.

I know I can do it myself, but M5stack should have done this already :-/

ajb2k3

@sj3fk3 said in Micropython - SHT30 in BTC Base:

I honestly don't understand M5Stack's way of working. There is this ENV2 with python support: https://docs.m5stack.com/#/en/unit/envII it has a SHT30, but then you spend $80 on a M5Paper and you don't get python support for the SHT30. How hard is it to put in the the right lib.

I know I can do it myself, but M5stack should have done this already :-/

Micropython on the M5Paper is in early alpha because we pushed M5Stack to get it out before the holiday. I spent yesterday doing some testing and I cannot get any SHT30 devices to work no matter if its the internal SHT30 on the paper or the env2 unit.
What lib are you using as I cant even get raw reg read and writes to work.

ajb2k3

@kedulowt said in Micropython - SHT30 in BTC Base:

temperature, humidity = sht30_sensor.measure()

I can't get this to work

  File "<stdin>", line 1, in <module>
  File "sht30.py", line 40, in __init__
NameError: name 'I2C' isn't defined
>>>

Wolli01

Vielleicht hilft euch das weiter. Läuft auf einem M5Stick-C

main.py

import unit
import machine
import array
import sht31

from machine import I2C, Pin
i2c = I2C(freq=100000, scl=Pin(32), sda=Pin(33) )
sensor = sht31.SHT31(i2c, addr=0x44)

while True:
#Sensor SHT31-----------------------------------------------------------
temp_humi = sensor.get_temp_humi()
wait_ms(600)
Temperatur = round(temp_humi[0],2)
Feuchte = round(temp_humi[1],2)
#Sensor SHT31-----------------------------------------------------------

sht31.py

from machine import I2C
import time

R_HIGH = const(1)
R_MEDIUM = const(2)
R_LOW = const(3)

class SHT31(object):
"""
Diese Klasse implementiert eine Schnittstelle zur SHT31 Temperatur und Luftfeuchtigkeit.
Sensor von Sensirion.
"""
# Diese statische Karte hilft, den Heap und die Programmlogik sauber zu halten.
_map_cs_r = {
True: {
R_HIGH : b'\x2c\x06',
R_MEDIUM : b'\x2c\x0d',
R_LOW: b'\x2c\x10'
},
False: {
R_HIGH : b'\x24\x00',
R_MEDIUM : b'\x24\x0b',
R_LOW: b'\x24\x16'
}
}

def __init__(self, i2c, addr=0x44):
    """
    Initialisiert ein Sensorobjekt auf dem angegebenen I2C-Bus, auf das von der
    angegebene Adresse.
    """
    if i2c == None or i2c.__class__ != I2C:
        raise ValueError('I2C-Objekt als Argument benÃ¶tigt!')
    self._i2c = i2c
    self._addr = addr

def _send(self, buf):
    """
    Sendet das angegebene Pufferobjekt Ã¼ber I2C an den Sensor.
    """
    self._i2c.writeto(self._addr, buf)

def _recv(self, count):
    """
    Lesen von Bytes vom Sensor Ã¼ber I2C. Die Anzahl der Bytes kann angegeben werden.
    als Argument.
    Liefert ein Bytearray fÃ¼r das Ergebnis.
    """
    return self._i2c.readfrom(self._addr, count)

def _raw_temp_humi(self, r=R_HIGH, cs=True):
    """
    Lesen Sie die Rohtemperatur und Luftfeuchtigkeit vom Sensor ab und Ã¼berspringen Sie CRC. ÃœberprÃ¼fung.
    Liefert ein Tupel fÃ¼r beide Werte in dieser Reihenfolge.
    """
    if r not in (R_HIGH, R_MEDIUM, R_LOW):
        raise ValueError('Falscher Wiederholbarkeitswert angegeben!')
    self._send(self._map_cs_r[cs][r])
    time.sleep_ms(50)
    raw = self._recv(6)
    return (raw[0] << 8) + raw[1], (raw[3] << 8) + raw[4]

def get_temp_humi(self, resolution=R_HIGH, clock_stretch=True, celsius=True):
    """
    Lesen Sie die Temperatur in Grad Celsius oder Fahrenheit und relativ dazu ab.
    Feuchtigkeit. AuflÃ¶sung und TaktverlÃ¤ngerung kÃ¶nnen festgelegt werden.
    Liefert ein Tupel fÃ¼r beide Werte in dieser Reihenfolge.
    """
    t, h = self._raw_temp_humi(resolution, clock_stretch)
    if celsius:
        temp = -45 + (175 * (t / 65535.0))
    else:
        temp = -49 + (315 * (t / 65535.0))
    return temp, 100 * (h / 65535.0)

sj3fk3

@ajb2k3 said in Micropython - SHT30 in BTC Base:

Micropython on the M5Paper is in early alpha because we pushed M5Stack to get it out before the holiday. I spent yesterday doing some testing and I cannot get any SHT30 devices to work no matter if its the internal SHT30 on the paper or the env2 unit.
What lib are you using as I cant even get raw reg read and writes to work.

For now I have abandoned micro python and switched to (yuck) C and platformio.