Hi,
I wanted to control brightness of “Cree XLamp MK-R” LED via PWM.
This LED has an input voltage of 7-48 V and PWM logic voltage of 3-48 V.
I have a Jetson TX2 board, please guide if this is feasible on this board.
If not please suggest some driver compatible with jetson TX2 board to achieve the same?
Yes, check out this post as well as this one; you can just vary the pwm duty cycle to vary brightness, the solution use the fan gpio to generate pwm signal, there is some limitations to this method but none that you should care about
Regards
Hi,
The link shared for configuring the 40 pin header for PWM, I have already tried that in jetson TX2 board but couldn’t find any option to configure a gpio as a PWM ( Maybe it is available with Jetson Nano board only).
And For the code shared by you is using a RPi library will it work with Jetson TX2.
Also is there any reference in C++ rather than in python?
may I know which pin you’re used, please access pinmux spreadsheets via download center.
you may change the pinmux configuration applied by the software, please refer to Pinmux Changes session.
thanks
The two topics you mentioned are using a JETSON NANO board but I wanted to do the same in JETSON TX2 board.
In my case as soon as i run the jetson-io.py i do not see any pwm options. Also if I choose configure 40 pin header option, PWM options are not even present.
As you suggested that we can do it by using sysnode please share the steps to do so for JETSON TX2 specifically.
I have been trying to generate PWM on the devkit without any success for the past 2 weeks.
it’s same, $ cat /sys/kernel/debug/pwm for checking PWM status.
you may enter /sys/class/pwm/ and using $ echo to export PWM using the commands.
for example,
Hi,
Thanks for the reply.
It is somewhat helpful but how can I test it? Is it directed to any GPIO pin on J21 header? How can I connect any led to test it?
may I know which pin on J21 you would like to used?
please also refer to device tree for the mappings of PWM,
as my above sample, it’s tegra_pwm1: pwm@3280000 {...}.
for example, $L4T_Sources/r32.5/Linux_for_Tegra/source/public/hardware/nvidia/soc/t18x/kernel-dts/tegra186-soc/tegra186-soc-pwm.dtsi
you should access pinmux spreadsheets to have customization if the default pin settings is not PWM.
you may also check developer guide, Jetson TX2 Series MB1 Platform Configuration,
please refer to [PWM Specific Commands] session for PWM specific commands in MB1-BCT,
thanks