MPU9250 with PWM logic

[Rahul]

Hello friends,

i am new to embedded programming and trying to learn the new things in embedded for this i am doing 1 project in which i am using mpu9250 with pwm.

is it possible to glow 4 different LEDs using single pwm module having four channels and how it can work at same time for same duty cycle.

i am also using mpu9250 for accelerometer values, how can i change this like if change in x direction then only 1 LED will glow and if change in y direction then different LED will glow.

i was trying by manipulating examples but only one LED is glowing. how can i implement this with proper logic.

please help me with this

thank you

[Bjørn Kvaale]

Hey Rahul. Just got an example working where I am using one pwm instance to increase the duty cycle of the four different leds on the nrf52 dk. Every 10 ms, the LED duty cycle increases by 1% up to 100%. Then, it starts from the beginning I believe. It was based on this simple example (pwm_simple.zip) I found in another devzone case. I've uploaded the source code below if you don't want to give it a try yourself ;)

But if I were you, I would try to start from the pwm_simple.zip example found in the other devzone case and see if you can figure it out yourself. That way, you'll learn more than just by looking at the answer below. Up to you. :)

Update: Source Code for nrf52832

[Bjørn Kvaale]

I would just look at the main.c file if I were you. I used Keil to compile, but it should work with any of the other compatible solutions too. I placed this example in the SDK 13 folder under "/examples/peripheral/pwm_simple". Otherwise, you will get errors since the pwm example uses other libraries located under the "SDK13/components/libaries" folder.

[Rahul]

hello sir what i want to do is i wanna use all the channels of single pwm module in different cases like we can use one channel at a time but when the mpu vales changes it should go to second channel then later values changes it should go to third channel like that

[Bjørn Kvaale]

Let me see if I understand this correctly: for example if the mpu value is between a theoretical value of:

• 0-1.9999, then LED 1 should blink
• 2-3.9999, then LED 2 should blink
• 4-6, then LED 3 should blink

Is this what you mean? And the LED intensity should be adjusted based on the MPU value too?

[Rahul]

yes exactly this i want to do

[Rahul]

i can easily do that using all the module but how can i do that using single module this is my concern