SHT21 HTU21

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Gotty101
Posts: 4
Joined: 27 Aug 2018 19:29

SHT21 HTU21

Post by Gotty101 » 28 Oct 2018 14:28

Hi hopefully someone will be able tohelp me as im at a blank at the mo. Ive bought the following sensor (link below) and mine came with the HTU21 chip
https://www.ebay.com/itm/SHT21-HTU21-Di ... :rk:3:pf:0

Its got a built in voltage regulator so ive connected it to +5v and ground. Ive then connected SCL to pin 9 and SCA to pin 10. I then used the following library (https://learn.adafruit.com/adafruit-htu ... g-and-test) which compiles and uploads to to the zuno fine.

Only problem is i just get the following output
Temp: -46.85 C Humidity: -6.00 %
Temp: -46.85 C Humidity: -6.00 %
Temp: -46.85 C Humidity: -6.00 %
Temp: -46.85 C Humidity: -6.00 %
Temp: -46.85 C Humidity: -6.00 %

Which shows its not actually getting the right value as i would be rather cold. Ive even tried I2C pull ups on SCL and SDA pins to 3.3v and its still the same. So basically has anyone managed to use this chip with a Zuno?

Ive successfully got the BH1750 I2C light sensor and INA219 voltage current sensor working fine. This is just the last main sensor to try and i can move forward with my project.

Many thanks

Trev

Gotty101
Posts: 4
Joined: 27 Aug 2018 19:29

Re: SHT21 HTU21

Post by Gotty101 » 24 Nov 2018 11:05

Hi just update. I've tried another sensor in case I had a bad one, and also with the sensor on the i2c bus on it's own with the pull up resistors and without. No matter I just get the same result.

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PoltoS
Posts: 4334
Joined: 26 Jan 2011 19:36

Re: SHT21 HTU21

Post by PoltoS » 04 Dec 2018 00:53

Are you using some library like DHT11/22 or you are reading I2C? Please check the specs for your sensor

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