Schmafu
Posts: 3
Joined: Sat May 26, 2018 11:00 am

Sense Hat and additional I2C Sensor?

Sat May 26, 2018 11:33 am

Hello,
I'm quite new to the RasPi world and I am thinking of using the sense-HAT but I would need some ADC's as well.. I found the ADS1115 that would fit pretty well an use the I2C bus.. But I was wondering if it is workings without any problem to add some additional I2C devices since I dont now how the sensors on the sense-HAT are wired....

If its possible to use an dditional I2C device would I just wire it the same way as any other I2C Slave or do I have to change anything?
Any how would I read the data?

for the sense-Hat I use the "official" source code thats linked on the page.
Thanks in advance for your help

Best regards,
the newbie :-)

alphanumeric
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Joined: Tue Jan 19, 2016 2:17 pm
Location: Sydney, Nova Scotia, Canada

Re: Sense Hat and additional I2C Sensor?

Sat May 26, 2018 10:48 pm

You can add other i2c devices as long as there is no address conflicts. This will show you the PINs used and what i2c addresses are used by the sensors. https://pinout.xyz/pinout/sense_hat#
I have a sense hat with a DS3231, Si1145 and BME680 all wired to the i2c BUS. i2c is a shared bus.

Schmafu
Posts: 3
Joined: Sat May 26, 2018 11:00 am

Re: Sense Hat and additional I2C Sensor?

Sun May 27, 2018 1:11 am

thanks for your help,
I had found the same page but somehow missedthe adresses already mentioned there :o ..

What I had in mind as a possible problem is the connection... do you just connect the additional sensors to the SDA and SCL line with a GPIO extension board? But wouldnt that be a parallel connection then, or am I wrong?

Thanks again :-)

alphanumeric
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Joined: Tue Jan 19, 2016 2:17 pm
Location: Sydney, Nova Scotia, Canada

Re: Sense Hat and additional I2C Sensor?

Sun May 27, 2018 8:53 am

Yes, you just connect them all in parallel. I added a proto hat mounted between my Pi and Sense Hat with a stacking header. On that I put male headers wired to the SDA SDL. The headers then go to my sensors via wiring harnesses. I used female jumper wires.
Pictures here if you want to see how I did it. https://1drv.ms/f/s!AjOYwiwlwDtpgsVkNRFKrcQ8HARM0Q I feed the V+ and ground to the sensors from the same headers. 4 wires to each sensor.

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bensimmo
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Location: East Yorkshire

Re: Sense Hat and additional I2C Sensor?

Sun May 27, 2018 7:47 pm

As above,
I use an extra long stacker header to expose the gpio pins above the sensehat. You use in in place of the ones provided. (New ones come with it seperate already my original one did not.)
For 'development'* I then plug the 40 pin ribbon cable in above the sensehat and to a T-cobbler I to a breadboard/prototype board.
It's then easy to add more i2c or other sensors for learning and trying.

After that, you can either use wires.directly or strioboard from 3.3/5/i2c's and gnd and solder it all up.


*Ok playing around ;-)

alphanumeric
Posts: 1538
Joined: Tue Jan 19, 2016 2:17 pm
Location: Sydney, Nova Scotia, Canada

Re: Sense Hat and additional I2C Sensor?

Sun May 27, 2018 10:19 pm

I also use a ribbon cable cobbler, on my prototyping Pi. That's all I use that Pi for is prototyping. https://1drv.ms/f/s!AjOYwiwlwDtpgq9LUHdGiiRpn7dr2Q

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bensimmo
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Location: East Yorkshire

Re: Sense Hat and additional I2C Sensor?

Mon May 28, 2018 9:20 am

I like that :-)

alphanumeric
Posts: 1538
Joined: Tue Jan 19, 2016 2:17 pm
Location: Sydney, Nova Scotia, Canada

Re: Sense Hat and additional I2C Sensor?

Mon May 28, 2018 10:50 am

bensimmo wrote:
Mon May 28, 2018 9:20 am
I like that :-)
Thanks. It's been modified and upgarded several times. I think it started with a 2B and WIFI dongle, then a 3B and camera. I just put a 3B+ in a few weeks ago. Display was upgarded from a 5 inch touch screen to the Pi foundation 7 inch. Having everything bolted together makes it portable enough to move it around the house fairly easily. I take it out on my deck under my gazebo in the summer sometimes. I do most of my tinkering in the summer months. Thats was my first major Pi related project. Really happy with how it turned out.

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