I’m guessing you’ve already realized this, but in case it helps clarify things for someone else:
The signals rates mentioned in the article are with respect to how frequently the segments are updated, not the brightness. (With the one exception being the colons being PWM controlled, IIRC).
PWM means Pulse Width Modulation. Controlling a (perceived) light intensity of an LED via PWM means (if we pretend for the sake of simplification that the voltage rise and fall is instantaneous, etc) quickly turning the LED fully on and fully off, varying the duty cycle to achieve the desired perceived brightness. This project avoids the flickering inherent with PWM by not using PWM: the voltage itself is set to some fixed value for a given target brightness.
(If one then wonders why this wouldn’t be the default approach for such things: microcontrollers often provide a built in means for PWM output, but it’s less common to have built in true, non-PWM analog outputs, requiring additional parts (thus more cost, more complexity) to implement variable voltage control).
The signals rates mentioned in the article are with respect to how frequently the segments are updated, not the brightness. (With the one exception being the colons being PWM controlled, IIRC).
PWM means Pulse Width Modulation. Controlling a (perceived) light intensity of an LED via PWM means (if we pretend for the sake of simplification that the voltage rise and fall is instantaneous, etc) quickly turning the LED fully on and fully off, varying the duty cycle to achieve the desired perceived brightness. This project avoids the flickering inherent with PWM by not using PWM: the voltage itself is set to some fixed value for a given target brightness.
(If one then wonders why this wouldn’t be the default approach for such things: microcontrollers often provide a built in means for PWM output, but it’s less common to have built in true, non-PWM analog outputs, requiring additional parts (thus more cost, more complexity) to implement variable voltage control).