Support for Grove CO2 Sensor?


#1

Hello,

Besides working to get the Grove Dust Sensor working, we also need to get the Grove CO2 Sensor working.

Do you have suggestions on getting this one working also? I’m looking on Github, but did not spot the Python examples for this one?

Thanks!


#2

Hey,
The CO2 sensor is compatible with the GrovePi but we don’t have one with us so haven;t written an example for it. We might do that in the future but we don;t have an ETA on that.

There was a discussion on this earlier here: http://www.dexterindustries.com/topic/how-to-use-co2-grove-sensor-with-serial-grovepi/ and there is some exapmple code there. Can you try that out and let us know if that works. We’ll add it in the GrovePi examples if it works well.

-Karan


#3

Hello,

Thanks … I’ll give this a try, and see how it works. I noticed that you mention the GrovePi serial port is not yet accessible? Only the RPiSer?

Can you provide a little more detail? What needs to be done to have the second one working also? Is there example code for that also?


#4

The SERIAL port on the GrovePi is connected to the Hardware Serial of the Atmega328 which is the MCU on the GrovePi. We are not using it right now with any sensors because it is much much more easier to use something like a Serial Prompt on the Raspberry Pi or a Python program to communicate with the Serial Sensors.

We mostly use it to debug tricky things by sending debug data via Serial. You can also use it to read Serial Data and send it back via I2C, but we haven’t come across a big application for this yet.

If you have any projects where you would like to specifically use the SERIAL port do let us know.

-Karan


#5

Hello,

Sorry … I have been buried with a project that we are about to deliver … I haven’t had time to catch up on testing the new firmware yet. I’ll be doing more work in the next week or two … :slight_smile:

I have a question about the RPiSER port … is it fully level shifted to 5vdc? Or is it a pass-thru at 3.3vdc from the RPi?

It’s recommended the CO2 sensor run at 5vdc, and when I plug it onto the RPiSer port, wacky things start to happen to my other sensors … almost like a power/current/voltage issue? I’m wondering if the CO2 sensor is drawing too much from the RPiSer?

First … I’m trying to figure out if it’s all 5vdc … and then what might be causing the problem when I connect it.


#6

Hey,
The RPISER port is level shifted to 5V. We use a bidirectional level converter to covet the signals from 3.3V on the Pi side to the 5V on the header. The header also has 5V going to the Grove sensor. The Grove page for the CO2 sensor states that it needs 100mA and I think the Pi should be able to provide that.

Can you double check if the TX and RX lines are connected properly with the schematic here: https://github.com/DexterInd/GrovePi/tree/master/Hardware.

-Karan