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.

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

NRST/RESET line doesn't require a pull-up resistor #25

Closed
stuartpittaway opened this issue May 17, 2023 · 2 comments
Closed

NRST/RESET line doesn't require a pull-up resistor #25

stuartpittaway opened this issue May 17, 2023 · 2 comments
Labels
triage for issues that need a first response and tagging

Comments

@stuartpittaway
Copy link

Version Number

What is the latest known version number where this issue is present?

Bugfix or Enhancement

potential enhancement

Description

Resistor R4 (10K) is a pull up on the RESET line - this doesn't appear to be required according to the datasheet.

Page 69 of datasheet - NRST pin characteristics

The NRST pin input driver uses the CMOS technology. It is connected to a permanent pullup resistor, RPU

Suggested Solution

Remove R4

@stuartpittaway stuartpittaway added the triage for issues that need a first response and tagging label May 17, 2023
@30350n
Copy link

30350n commented May 17, 2023

For reference, there was already some discussion on this topic in #16.

@sphawes
Copy link
Member

sphawes commented May 24, 2023

Thanks for the issue @stuartpittaway! We originally followed the datasheet and didn't have that resistor, but we found that it was too weak. In some feeders, when the peel motor would power on it would lightly couple to the reset trace and cause a reset. Adding a stronger external pullup fixed the issue!

Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
Labels
triage for issues that need a first response and tagging
Projects
None yet
Development

No branches or pull requests

3 participants