Hi,
Can somebody please help me figure out why changing from a DHT11 to a DHT22 introduces random spikes at 25°C?
I removed the DHT11 which had a built-in 10k bias resistor for the data line, and then installed a DHT22 sensor and added the 10k pullup myself.
Both sensors used the same pin on the ESP8266.
I also changed the DHT platform in my YAML config from model: DHT11 to model: DHT22.
The DHT22 is powered with 3V3 (which is also what I connected the 10k bias resistor on the data pin to).
EDIT: I’ve found a lot of different datasheets for the DHT22, but this seems to be the only one with the original manufacturer’s name (Aosong) listed so I think this is the official datasheet. But it’s hosted by Seeed Studio so I don’t know if it’s the latest revision.
DHT22 (Aosong) Datasheet
In case my code is relevant, please see below.
################################################################################
# Define variables
################################################################################
substitutions:
# Device Properties
devicename: dev-air-quality
friendly_name: Dev-Air-Quality
device_topic: AirQuality
device_sleephelper: input_boolean.esphome_disable_deep_sleep
device_sleephelper_topic: admin/esphome_disable_deep_sleep
# Logger Properties
# This is used for the ESP_LOGx syntax, but not logger.log.
log_tag: yaml
# Sleep Properties
sleep_time: 2min #54s #2min #10s #2min #1min #5min #10s
# For API mode, run time needs to be roughly 10s. 5s failed because there wasn't enough time to read the binary sensor and prevent deeps sleep. The minimum run time is probably betwen 5s and 10s.
run_time: 1s #2s #1s
# The sensor will report data on boot, and then again for each sensor on their independent update_interval parameters until put to sleep again.
# Set update interval to a longer time than run_time to ensure only 1 data update per wake.
# I suspect that the update interval still has to be shorter than sleep time though. Otherwise the device seens to wake up and not publish
global_update_interval: $sleep_time
# Pinout
# Wake D0 # GPIO16 - Wake (deep sleep) - high at boot.
pin_i2c_scl: D1 # GPIO5
pin_i2c_sda: D2 # GPIO4
# Reserved D3 # GPIO0 - biased high - connected to flash button
# Reserved D4 # GPIO2 - biased high - connected to on-board LED
pin_rx: D5 # GPIO14
pin_tx: D6 # GPIO12
pin_dht: D7 # GPIO13
# D8 # GPIO15 - biased low
# RX # GPIO3
# TX # GPIO1 - debug output at boot
# A0 # ADC0
globals:
- id: shutdown_reason
type: std::string
restore_value: no
initial_value: '"normal deep sleep"'
################################################################################
# Define Device
################################################################################
esphome:
name: $devicename
on_boot:
then:
- logger.log:
format: "Booted"
level: ERROR
on_loop:
on_shutdown:
- logger.log:
format: "Normal Deep Sleep"
level: ERROR
esp8266:
board: d1_mini
# Enable logging
logger:
level: DEBUG #WARN
# Publish logs to MQTT
on_message:
level: WARN
then:
- mqtt.publish:
topic: $device_topic/logger
payload: !lambda |-
return "Level: " + to_string(level) + " ||| Tag: " + tag + " ||| Message: " + message;
# Enable Over-The-Air flashing
ota:
#safe_mode: True
password: !secret ota_password
on_end:
- logger.log:
format: "OTA Update"
level: ERROR
################################################################################
# Power
################################################################################
deep_sleep:
id: deep_sleep_control
sleep_duration: $sleep_time
run_duration: $run_time
################################################################################
# Wireless Access
################################################################################
wifi:
id: wifi_client
power_save_mode: LIGHT #There are other options. Just checking if this helps with self heating.
fast_connect: true # Skip wifi scan to save time.
ssid: !secret wifi_ssid
password: !secret wifi_password
# Set a static IP address.
manual_ip:
static_ip: 192.168.86.200
gateway: 192.168.86.1
subnet: 255.255.255.0
# If changing the name or the IP address of the device, this provides the old address so that ESPHome knows which device to overwrite.
use_address: "192.168.86.200"
################################################################################
# Home Assistant Connection
################################################################################
# Enable MQTT
mqtt:
id: mqtt_client
broker: !secret mqtt_broker
port: !secret mqtt_port
username: !secret mqtt_user
password: !secret mqtt_password
discovery: true
discovery_retain: true
# Set empty birth and will messages to avoid showing unavailable during sleep
birth_message:
will_message:
topic_prefix: $device_topic
on_message:
- topic: $device_sleephelper_topic
qos: 0 #1
payload: 'on'
then:
- logger.log:
format: 'MQTT Admin: disable deep sleep'
level: ERROR
- deep_sleep.prevent: deep_sleep_control
- topic: $device_sleephelper_topic
qos: 0 #1
payload: 'off'
then:
- logger.log:
format: 'MQTT Admin: entering deep sleep'
level: ERROR
- deep_sleep.enter: deep_sleep_control
################################################################################
# Communication Protocols
################################################################################
i2c:
sda: $pin_i2c_sda
scl: $pin_i2c_scl
id: bus_i2c
scan: False # Save time by skipping the I2C scan on startup since all addresses are known. Defaults to True
frequency: 50kHz # Defaults to 50kHz, SCD30 can't handle more than 100kHz.
################################################################################
# Functionality
################################################################################
# Air Quality, Temperature and Humidity.
sensor:
# DHT11 Temperature and Humidity Sensor
- platform: dht
model: DHT22 #DHT11
pin: $pin_dht
temperature:
name: "$friendly_name Temperature"
id: temperature
humidity:
name: "$friendly_name Humidity"
id: humidity
update_interval: $global_update_interval
# CO2, Temperature and Humidity
- platform: scd30
i2c_id: bus_i2c
address: 0x61
automatic_self_calibration: true
update_interval: $global_update_interval
co2:
name: "$friendly_name CO2"
id: co2
accuracy_decimals: 1
temperature:
name: "$friendly_name Temperature SCD"
id: temperature_scd
accuracy_decimals: 2
filters:
- offset: 0
humidity:
name: "$friendly_name Humidity SCD"
id: humidity_scd
accuracy_decimals: 1
#temperature_offset: 1.5 °C
# TVOC, Estimated CO2
- platform: sgp30
i2c_id: bus_i2c
address: 0x58
store_baseline: yes
update_interval: $global_update_interval
eco2:
name: "$friendly_name eCO2"
id: eco2
accuracy_decimals: 1
tvoc:
name: "$friendly_name TVOC"
id: tvoc
accuracy_decimals: 1
