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HTU21D Sensor?
Posted: 19 Dec 2015, 23:12
by rmtucker
HTU21D Humidity and Temperature Sensor
Anyone got this sensor working?
I thought it was compatible with the SI7021 but i can not get it too work.
Re: HTU21D Sensor?
Posted: 20 Dec 2015, 01:24
by fluppie
Same here, 2 sensors are found by the I2C scanner but it's not working.
Re: HTU21D Sensor?
Posted: 20 Dec 2015, 01:42
by rmtucker
Mine will not even show up in the scanner.
But it works perfectly on the arduino pro mini and mysensors?
Re: HTU21D Sensor?
Posted: 20 Dec 2015, 15:13
by rmtucker
Found the problem.
The delays after conversion are not correct in the source code.
Re: HTU21D Sensor?
Posted: 11 Oct 2016, 20:52
by Reley
I am fighting with a ESP-12E and a HTU21D...
I cannot get it to work. I am using the latest ESPEasy firmware (137).
I connect the + to the 3v3 pin, the - to the ground pin.
then the SDA GPIO-4 and SDL to GPIO-5
In ESP Easy I configure a SI7021 with correct IDX for Domoticz. This IDX is a dummy in Domoticz.
I have set Delay 55 in the config but still I receive:
300649 : SI7021 : Res=0x80 => Error 0x1
300650 : SI7021 : Read Error!
Also the IC2scanner remains empty if I scan....
What am i doing wrong here?
When I connect the sensor to my Uno, I can read the values.. so the sensor does work...
Re: HTU21D Sensor?
Posted: 18 Oct 2016, 10:09
by Reley
Reley wrote:I am fighting with a ESP-12E and a HTU21D...
I cannot get it to work. I am using the latest ESPEasy firmware (137).
I connect the + to the 3v3 pin, the - to the ground pin.
then the SDA GPIO-4 and SDL to GPIO-5
In ESP Easy I configure a SI7021 with correct IDX for Domoticz. This IDX is a dummy in Domoticz.
I have set Delay 55 in the config but still I receive:
300649 : SI7021 : Res=0x80 => Error 0x1
300650 : SI7021 : Read Error!
Also the IC2scanner remains empty if I scan....
What am i doing wrong here?
When I connect the sensor to my Uno, I can read the values.. so the sensor does work...
nobody with a hint?
Re: HTU21D Sensor?
Posted: 18 Oct 2016, 14:34
by costo
Are you having pull-up resistors on SCL & SDA ?
chech your sensor to see if it has pull-ups, the ESP12 does not have any. You can check with a voltmeter, SDA & SCL should be close to 3.3 volt. If not connect 2 4k7 resistors between Vcc and the I2C bus.
Re: HTU21D Sensor?
Posted: 19 Oct 2016, 09:17
by Reley
Both SCL and SDA have 3,something volt. (close to 3,3)
This means I do not need resistors right?
It is a NodeMCU 1 board running the latest ESP easy...
I tested with a DHT11 and this works fine with ESP easy.
On an Arduino, this HTU21D works fine as well..