Task Owner:

Who owns this task and will approve the final deliverables? Lazar

Objectives & Goals:

1. How does this task relate to the value track(s)?

- All of the effort we put into improving our product lines should provide value to our customers.
- We need to be able to clearly articulate the value each improvement will provide in the following three value tracks:
    1. Development - The hardware chapter is important for evaluating the Omega modules for a new project and supporting developers in the development process.
    2. Deployment
    3. Production

2. Create a short statement explaining the objectives and goals for this ticket.

Intro

The Omega’s SoC has a number of PWM modules. The Omega2 exposes two (2) PWM hardware modules on its pin headers while the Omega2S exposes all four (4).

Context

PWM (Pulse-width modulation) is a technique of producing varying analog signals from a digital source
- Duty cycle = percentage of time the signal is high (0-100)
- Frequency = signal frequency

Hardware

Hardware-based PWM
- Omega2/2+: 2 channels, Omega2S/2s+: 4 channels
- The hardware PWM modules have a frequency range of 39Hz to 40MHz.
  - For lower frequencies it is recommended to consider an external hardware PWM generator or the use of a software generated PWM signal from a GPIO pin.
- Include a table of the pins - see https://documentation.onioniot.com/hardware-interfaces/pwm#enabling-pwm-pins
Pinout diagrams of Omega2, Omega2S with PWM pins highlighted

Software

Enabling Hardware PWM
- Reuse existing section in document - https://documentation.onioniot.com/hardware-interfaces/pwm#enabling-hardware-pwm
Adjusting Pin Multiplexing to Enable PWM Pins
- Reuse existing section in document - https://documentation.onioniot.com/hardware-interfaces/pwm#enabling-pwm-pins
Generating PWM signals
- Reuse existing section in document - https://documentation.onioniot.com/hardware-interfaces/pwm#generating-pwm-signals
- Include a note about the script:
  - Helpful wrapper around sysfs for pwm
  - Source is available at: https://github.com/OnionIoT/OpenWRT-Packages/blob/openwrt-22.03/omega2-base/files/usr/lib/onion-pwm-lib.sh
Note: can remove the “Writing your own script to generate PWM signals” section

Reference Material:

1. Provide hyperlinks for helpful and related information.

Deliverables or Desired Outcome:

1. What are the task owners expectations?

Articles should be succinct, and minimalist.
These are MVP articles, and we will expand on them as users provide feedback and requests.
All articles from the Hardware chapter will go in the hardware branch.

2. What does the task owner require for a successful completion of the ticket?

i.e. sample code, drawings, documents etc.
a succinct article that follows our current style guide based on the original article

Date Required By:

1. When is the scope required to be completed?

no date has been specified

2. Is this a hard date? Specify if the task is a dependency of another task or if it will impact a customer requirement.

Ticket #44 has a dependency on this ticket to be completed

remingtontr commented 3 months ago

Ready for initial review.

greenbreakfast commented 2 months ago

@remingtontr looking good. I added some suggestions and comments.