I2C multiple same sensors (SI7021)

Moderators: grovkillen, Stuntteam, TD-er

Post Reply
Message
Author
hasanpb
New user
Posts: 6
Joined: 19 Apr 2016, 10:48

I2C multiple same sensors (SI7021)

#1 Post by hasanpb » 07 Sep 2017, 18:14

Hi,
I would like to ask you, if it is possible to connect more than one of same sensor (SI7021) on one I2C bus on ESPEASY.

Thanks
Top
User avatar
toffel969
Normal user
Posts: 469
Joined: 03 Jan 2017, 10:58
Location: Germany

Re: I2C multiple same sensors (SI7021)

#2 Post by toffel969 » 07 Sep 2017, 19:04

hasanpb wrote: ↑07 Sep 2017, 18:14 Hi,
I would like to ask you, if it is possible to connect more than one of same sensor (SI7021) on one I2C bus on ESPEASY.

Thanks
No you cannot connect two i2c with same adress
Domoticz on Raspi 2 -- 14 ESP units (hacked Sonoff,NodeMCUs, Wemos, self-built units) running with RC140- Mega 2.0.0 dev8
Top
hasanpb
New user
Posts: 6
Joined: 19 Apr 2016, 10:48

Re: I2C multiple same sensors (SI7021)

#3 Post by hasanpb » 07 Sep 2017, 21:19

Ok. Thanks for answer.
Top
papperone
Normal user
Posts: 497
Joined: 04 Oct 2016, 23:16

Re: I2C multiple same sensors (SI7021)

#4 Post by papperone » 07 Sep 2017, 23:10

Yes, you can do it of course! using a (still!) not supported I2C expander named TCA9548A.
There were some discussion on how to implement it in ESPEasy but due to the not easy intergation with current I2C handler it was decided to park it for release 2.1
My TINDIE Store where you can find all ESP8266 boards I manufacture --> https://www.tindie.com/stores/GiovanniCas/
My Wiki Project page with self-made PCB/devices --> https://www.letscontrolit.com/wiki/inde ... :Papperone
Top
Shardan
Normal user
Posts: 1156
Joined: 03 Sep 2016, 23:27
Location: Bielefeld / Germany

Re: I2C multiple same sensors (SI7021)

#5 Post by Shardan » 08 Sep 2017, 15:04

as i2c is of limited lenght you would be able to place
two si7021 on a distance of about 1 m reliably.
How much sense would that make?

Basically it is possible to use i2c expander to extend the length.
Expander and a doubler chip might work ... i'd prefer a second esp in that case.

It usually gets out of mind that i2c was devsloped as an in-box bus system
for tv sets, cd players and such.

Regards
Shardan
Regards
Shardan
Top
Post Reply

Return to “ESP Easy: Software”

Who is online

Users browsing this forum: No registered users and 15 guests