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sumotoy / RA8875

A library for RAiO RA8875 display driver for Teensy3.x or LC/Arduino's/Energia/Spark
GNU General Public License v3.0
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Add Code to use PWM on the LED backlighting Pin 14 (BL_Control). #82

Closed sbfreddie closed 8 years ago

sbfreddie commented 8 years ago

Max: Please add code to impliment PWM of the backlighting control (pin 14) on Teensy 3.x. I think this would be a great improvement to control the amount of power the 7" display is using.

Thanks for considering this improvement, Freddie

sumotoy commented 8 years ago

The brightness command already use the internal pwm pin to control the backlight! Did you try it?

sbfreddie commented 8 years ago

Max: I cannot find any mention of the brightness command on the WIKI or the examples, or which pin to connect it to on the Teensy 3.1. Have you any help located anywhere else? Thanks, Freddie

On Jan 2, 2016, at 5:16 PM, max mc costa notifications@github.com wrote:

The brightness command already use the internal pwm pin to control the backlight! Did you try it?

— Reply to this email directly or view it on GitHub https://github.com/sumotoy/RA8875/issues/82#issuecomment-168437910.

sumotoy commented 8 years ago

The RA8875 has 2 GPIO with PWM capabilities, Eastrising displays and Adafruit use one of these GPIO's for backlight. The brightness command uses PWM of the GPIO and Don't Need any MCU extra pin! On startup and initialization, display has been set at max (255), using brightness at less than 255 just after 'begin' will force display to consume much less current.

sbfreddie commented 8 years ago

Max: Thanks for that info. Please add this info to the WIKI. What is pin 14 on the ER-TFTM070-5 7" TFT Display Board Connector JP3 for?

Thanks, Freddie

On Jan 3, 2016, at 4:52 AM, max mc costa notifications@github.com wrote:

The RA8875 has 2 GPIO with PWM capabilities, Eastrising displays and Adafruit use one of these GPIO's for backlight. The brightness command uses PWM of the GPIO and Don't Need any MCU extra pin! On startup and initialization, display has been set at max (255), using brightness at less than 255 just after 'begin' will force display to consume much less current.

— Reply to this email directly or view it on GitHub https://github.com/sumotoy/RA8875/issues/82#issuecomment-168488650.

sumotoy commented 8 years ago

I think it was provided for use with a possible external pwm source, If I remember well there's a jumper for that, normally it's connected to RA8875 PWM GPIO