Brightness control on ST7789C/ AXP202
Brightness control on ST7789C/ AXP202
Have a TTgo 2020 watch (very cool) running on Russ' micropython firmware (https://github.com/russhughes/st7789_mpy). Trying to lighten power consumption by dimming (not blanking/ turning power off) the screen. Does anyone have ideas how to do this? There are suggestions to lower the PWM, but I don't see similar parameters initialising the ST7789 or AXP202.
Re: Brightness control on ST7789C/ AXP202
The docs I read say the blacklight is driven off the axp202c LDO2 and it's voltage is configurable between 1800mv (1.8v) and 3300mv (3.3v).
I have not tried this but you could try using setLDO2Voltage to change the voltage driving the backlight.
axp = axp202c.PMU()
axp.enablePower(axp202c.AXP202_LDO2)
# high
axp.setLDO2Voltage(3300)
#medium
axp.setLDO2Voltage(2400)
# low
axp.setLDO2Voltage(1800)
I have not tried this but you could try using setLDO2Voltage to change the voltage driving the backlight.
axp = axp202c.PMU()
axp.enablePower(axp202c.AXP202_LDO2)
# high
axp.setLDO2Voltage(3300)
#medium
axp.setLDO2Voltage(2400)
# low
axp.setLDO2Voltage(1800)
Re: Brightness control on ST7789C/ AXP202
Setting values 2400 and 1800 cause the screen to go black. The lowest tried that works is 2600. My low/ medium/ high settings are 2600, 2950, 3300 respectively.russ_h wrote: ↑Tue Jul 28, 2020 7:01 pmThe docs I read say the blacklight is driven off the axp202c LDO2 and it's voltage is configurable between 1800mv (1.8v) and 3300mv (3.3v).
I have not tried this but you could try using setLDO2Voltage to change the voltage driving the backlight.
axp = axp202c.PMU()
axp.enablePower(axp202c.AXP202_LDO2)
# high
axp.setLDO2Voltage(3300)
#medium
axp.setLDO2Voltage(2400)
# low
axp.setLDO2Voltage(1800)
Thanks!
Re: Brightness control on ST7789C/ AXP202
jhfoo wrote: ↑Wed Jul 29, 2020 5:50 pmSetting values 2400 and 1800 cause the screen to go black. The lowest tried that works is 2600. My low/ medium/ high settings are 2600, 2950, 3300 respectively.russ_h wrote: ↑Tue Jul 28, 2020 7:01 pmThe docs I read say the blacklight is driven off the axp202c LDO2 and it's voltage is configurable between 1800mv (1.8v) and 3300mv (3.3v).
I have not tried this but you could try using setLDO2Voltage to change the voltage driving the backlight.
axp = axp202c.PMU()
axp.enablePower(axp202c.AXP202_LDO2)
# high
axp.setLDO2Voltage(3300)
#medium
axp.setLDO2Voltage(2400)
# low
axp.setLDO2Voltage(1800)
Notes: 2500 works too but it's too dim to be usable.
Thanks!