so i am having some problems trying to figure this out. I have a khadas vim 3 unit its 100% hidden so i cant push the buttons. I wanted to see if anyone has a way to put it in and out of sleep when you turn the car on or off. Asked on their forms not really much help. Really struggling with this one.
You can put the button wires out
There are unsoldered PWR pins on the board, see the diagram on the official site!
I am also using the Khadas VIM3. I have a similar problem. I am currently using an Arduino to pulse the PWR pin, and that does work. However, it is easy for it to get out of sync, and trigger at the wrong times. I have another scheme in mind to prevent that, but it would be far easier if it would work like the Udoo x86, or other devices in the marketplace that just use a logic level (ie, 0 = off, 1 = on). I inquired about this on the Khadas forum. They gave me some pointers, but I am certainly not an Android developer, so I have not been able to make this work, although I can read logic levels of the VIM3’s GPIO pins in Android Terminal. Here’s a link to my thread on the subject:
https://forum.khadas.com/t/vim3-android-power-suspend-by-voltage-level-gpio/10848/13
wish there way some sort of android device for cars that just has hdmi inputs
I did find this:
I did find this:
https://mausberry-circuits.myshopify.com/collections/car-power-supply-switches/products/4amp-car-supply-switch
but not sure about how to be able to turn the kahdas on and off with this device. Wish that Realdash worked on linux and we could use use a raspberry pi!
do you found a way to turn on and off the khadas and screen when ignition if on/off?
I’d love to know more about what the GPIO signals it uses are. I have considered tapping into the VIM3’s status LEDs to gain feedback, to feed to the Arduino, to set a status flag on power state. I may just have to do that.
The VIM3 is frustrating, in that it uses a power switching scheme more appropriate for a tablet, than an embedded computer. If you read their responses in the thread I posted above, you can see that they aren’t going to do anything about it, either. Pretty disappointing. Khadas has a workaround for it, and anyone with an ounce of Android programming experience can probably whip up a programming solution in a matter of minutes. Unfortunately, that is not in my skill set.
I do not have programming skills in android … but after reading the topics I made sleep control …
and by the way, at least VIM3 knows how to sleep deeply … VIM3L - does not even know how to sleep.
but I agree with you that all these are “crutches” that have to be tinkered due to the fact that the developers did their job poorly.