Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Jump to bottom

CO Sensor, analog ground reference not connected #7

Open
clayton13 opened this issue Feb 22, 2021 · 1 comment
Open

CO Sensor, analog ground reference not connected #7

clayton13 opened this issue Feb 22, 2021 · 1 comment
Labels
bug Something isn't working schematic

Comments

@clayton13
Copy link
Member

The LMP91000's GNDA is not directly connected to the system digital GND or to the ground of the ADC.
@clayton13 clayton13 added bug Something isn't working schematic labels Feb 22, 2021
@clayton13
Copy link
Member Author

Temporary fix: simply short the localized GNDA into system global GND. This can be achieved by shorting The GNDA side of R601 or C601 to the ground pour.

Going forward: a local nettie will have to be added or GNDA should be replaced with GND.

Schematic Options
image image

After employing the 🔴 option above, I was able to get correct (enough) analog readings from the LMP's internal temperature sensor. The separated grounds lead to an erroneous measurement of ~0.5V over expected.

Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
Assignees
No one assigned
Labels
bug Something isn't working schematic
Projects
None yet
Milestone
No milestone
Development

No branches or pull requests
1 participant
@clayton13