I am trying to connect my sensirion sps30 dust sensor to the adafruit QT 3V to 5V Level Booster Breakout on I2C. I will need to connect both pins 4 & 5 on the sps30 to ground. I am not entirely sure how to combine the 2 pins to the ground input of the level booster! A rather basic question! Any ideas?
jst connector on sps30
level booster ( connecting to the 5v side)
Help with I2C connection
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- dastels
- Posts: 15653
- Joined: Tue Oct 20, 2015 3:22 pm
Re: Help with I2C connection
First of ALL grounds should connect together unless you're using isolation of some sort, e.g. an optoisolator.
For those two ground pins, just connect them both to ground.
Now, exactly what hardware do you have, and how do you have t connected?
Dave
For those two ground pins, just connect them both to ground.
Now, exactly what hardware do you have, and how do you have t connected?
Dave
- juju01
- Posts: 44
- Joined: Fri Mar 23, 2018 1:43 pm
Re: Help with I2C connection
Hi Dave
Yes I am looking to do what you suggest - connect all grounds. I havent connected anything yet.
I am looking to connect the sensirion sps30 dust sensor to the adafruit 3v-5v booster on a raspberrypi. The plan is to do this:
sps30 --> 3v -5v booster -- use qwiic connection to --> raspberrypi qwiic hat.
So I am just confused how to connect the 2 grounds on the sps30 to the 5v booster ( as stated in my original question ).
V
Yes I am looking to do what you suggest - connect all grounds. I havent connected anything yet.
I am looking to connect the sensirion sps30 dust sensor to the adafruit 3v-5v booster on a raspberrypi. The plan is to do this:
sps30 --> 3v -5v booster -- use qwiic connection to --> raspberrypi qwiic hat.
So I am just confused how to connect the 2 grounds on the sps30 to the 5v booster ( as stated in my original question ).
V
- dastels
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- Joined: Tue Oct 20, 2015 3:22 pm
Re: Help with I2C connection
What sensor board? What 3v-5v "booster"?
If you don't answer my questions, there's not much I can do to help.
Dave
If you don't answer my questions, there's not much I can do to help.
Dave
- juju01
- Posts: 44
- Joined: Fri Mar 23, 2018 1:43 pm
Re: Help with I2C connection
Pardon me - I thought all that info is already up there. Perhaps I misunderstand your question.
Sensor board - Sensiron SPS30 https://www.sparkfun.com/products/15103
Adafruit QT 3V to 5V Level Booster Breakout - STEMMA QT / QwiicWhat 3v-5v "booster"?
https://www.adafruit.com/product/5649
On Raspberrypi 4b.
Is this the info you were looking for?
- dastels
- Posts: 15653
- Joined: Tue Oct 20, 2015 3:22 pm
Re: Help with I2C connection
That's it. Thanks.
According to the docs for the sensor:
As for grounds, they get connected together. All grounds MUST be connected together. That establishes a common understanding of all other voltages/signals. What about it is confusing? the electrical connection? How to connect them physically?
Dave
According to the docs for the sensor:
So you shouldn't need the booster.The SPS30 requires a 5V power supply, but can work with 3.3V and 5V microcontrollers. The logic is 5V and 3.3V tolerant.
As for grounds, they get connected together. All grounds MUST be connected together. That establishes a common understanding of all other voltages/signals. What about it is confusing? the electrical connection? How to connect them physically?
Dave
- juju01
- Posts: 44
- Joined: Fri Mar 23, 2018 1:43 pm
Re: Help with I2C connection
The sensor itself requires a 5V supply. It's the SDA/SCL pins that are 5v/3v tolerant.
I realize I can connect everything directly to the pi4 pins, but I am looking to use a stemma qt adapter on the Pi to manage all my sensor connections. I have three other sensors, all using the stemma interface so makes it cleaner. That's why I decided to use the Booster, which also has the stemma connector.
https://www.adafruit.com/product/4688
My confusion is how to physically connect the two ground pins ( pin 4 /5) to the ground on the booster.
I realize I can connect everything directly to the pi4 pins, but I am looking to use a stemma qt adapter on the Pi to manage all my sensor connections. I have three other sensors, all using the stemma interface so makes it cleaner. That's why I decided to use the Booster, which also has the stemma connector.
https://www.adafruit.com/product/4688
My confusion is how to physically connect the two ground pins ( pin 4 /5) to the ground on the booster.
- dastels
- Posts: 15653
- Joined: Tue Oct 20, 2015 3:22 pm
Re: Help with I2C connection
Yeah, that's probably the safe route for the Pi.
How are you connecting the sensor cable to the I2C boost? The boost has a ground pad on each side which are connected together.
Dave
How are you connecting the sensor cable to the I2C boost? The boost has a ground pad on each side which are connected together.
Dave
- juju01
- Posts: 44
- Joined: Fri Mar 23, 2018 1:43 pm
Re: Help with I2C connection
This answers my question. ThanksThe boost has a ground pad on each side which are connected together.
Please be positive and constructive with your questions and comments.