• Christoph Thelen's avatar
    Update rmt translator (#3629) · 14cdff10
    Christoph Thelen authored
    * Choose the number of RMT buffers in the ws2812 module.
    
    The number of buffers required for optimal operation should be selected
    by the ws2812 module, not the caller.
    
    * Add parameters for RGB LED bit times.
    
    This patch adds compatibility for different RGB LEDS besides the WS2812.
    ESP evaluation boards like the ESP32-C3-DevKitM-1 use an SK68XXMINI-HS
    RGB LED which does not respond to the timings of this module.
    The patch adds optional parameters for the bit timings to the write
    function. If the new parameters are not supplied, the old values are used.
    An example for the SK68XXMINI-HS is provided in the documentation.
    
    * Remove restrictions from RTM translator.
    
    The old RMT translator was not able to split the bits of the source
    data into the size requested by the RMT transmitter. Either all 8 bits
    of an input byte were translated or none.
    The new routine removes the restriction by delivering exactly the
    requested amount of data to the transmitter, which results in a more
    balanced buffering of translated data under load.
    
    * Add a parameter for the RGB LED reset time.
    
    This patch introduces a new optional parameter for the reset time
    in the RGB LED communication. The default is 51.2 microseconds. A
    value of 0 sends no reset signal, which allows a small optimisation
    for consecutive write commands.
    
    Please note that the reset time of the old code should be 50
    microseconds, as the define WS2812_DURATION_RESET suggested. Due to the
    restrictions of the old RMT translator routine, it was slightly
    increased to 51.2 microseconds. This patch keeps the value of 51.2
    microseconds to be as compatible as possible.
    
    * Minimize the time drift between RMT channels.
    
    Place all RMT channels in a group to minimize the time drift between
    the signals. Please note that this feature is not available on all
    platforms.
    
    * Fix the description of the SK6812 LED in the example code.
    
    The SK6812 expects the data for the green LED first, then red and
    finally blue. It should be described as a GRB LED.
    14cdff10
ws2812.md 10.5 KB