Hi all, Just a question about the electronic design of the Navigator board. Concerning the PCA9685PW chip, why did you choose an external clock of 24.576Mhz instead of the internal one of 25Mhz? Thanks Best regards. Thierry

Hi @ThierryB , welcome to the forum :slight_smile: [image] ThierryB: Concerning the PCA9685PW chip, why did you choose an external clock of 24.576Mhz instead of the internal one of 25Mhz? As I understand it the internal one wasn’t very accurate, which is frequently the case for internal clock…

[image] Eliot: I’ll confirm with the design team. Following up, the issue was indeed inaccuracies with the internal clock. In case it’s relevant, I asked for clarification on whether that’s and was told

Thanks a lot for your responses. Clear for me. So not really a issue with the frequency but with stability as well as variance from a chip to another. Thanks. Regards

[image] ThierryB: not really a issue with the frequency but with stability as well as variance from a chip to another. Not an issue with the regularity of the frequency, but yes an issue with the accuracy of the frequency, and inconsistency between chips - e.g. specifying 50 Hz with two chips…

Clear for me. Thanks for your explanations. I will not make the economy of an oscillator then. regards

Navigator PCA9685 clock choice

Blue Robotics Products Flight Controllers

Topic		Replies	Views
T100 and adafruit pca9685 General Discussion thruster	4	1704	April 5, 2021
Splitting PWM (PPM) data between two PCA9685PW chips on the same I2C bus BlueOS	5	80	May 4, 2026
PWM Frequency For Basic ESC Speed Controllers (ESCs) basic-esc	4	6088	March 9, 2020
Navigator Lib - PWM Outputs C++ Blue Robotics Software navigator	7	487	March 26, 2024
Navigator+Pi4 Change PWM Outputs from 400Hz to 50Hz Flight Controllers navigator	2	1202	October 6, 2022

Community

BR Website

Software Docs

Autopilot Docs

BR and Beyond

Software

Navigator PCA9685 clock choice

Community

BR Website

Software Docs

Autopilot Docs

BR and Beyond

Software

Navigator PCA9685 clock choice

Related topics