I'm having trouble reaching 3.3 volt with the adafruit thumb joystick. I can only get about 2.5 volts to the adc pin.
I'm thinking of connecting it to 5 volts instead and scale it down with a resistor to reach 3.3 volt at full stroke of the joystick.
I can't find any 5 volt pin so I'm thinking of making my own, soldering a wire from the usb connector, but everything is so very tiny. Is there a better place to pick upp +5 volts?
Am I thinking this wrong or how would you do it?
Reaching 3.3 volt?
Re: Reaching 3.3 volt?
The VIN pin should have 5v (well closer to 4.75V) on it when you power the board via USB.
Re: Reaching 3.3 volt?
I would measure the resistance of your joystick over the full range of motion.
The way the joysticks are typically wired up, you have some total resistance, which you can measure between Vcc and GND. The Xout anYout are then essentially taps into that (so the center post on a potentiometer).
One you know the total resistance and the high and low resistance measured between Xout/Yout and GND then we can calculate what additional resistance you need to make it work over the full range of 3.3v
The way the joysticks are typically wired up, you have some total resistance, which you can measure between Vcc and GND. The Xout anYout are then essentially taps into that (so the center post on a potentiometer).
One you know the total resistance and the high and low resistance measured between Xout/Yout and GND then we can calculate what additional resistance you need to make it work over the full range of 3.3v
Re: Reaching 3.3 volt?
I solved it. I just assumed that the MIC2005A was a 5 volt regulator for the usb port 
The problem seems to be that the potentiometer on the joystick dont change its resistance the last few mm's before the end stop. Don't know how to fix that...
I tried with a normal 10K pot and it worked fine, even with 3.3 volts i could scale the numbers more then enough for my needs.
Thanks alot anyway. I bet I will come upp with more stupid questions for you
The problem seems to be that the potentiometer on the joystick dont change its resistance the last few mm's before the end stop. Don't know how to fix that...
I tried with a normal 10K pot and it worked fine, even with 3.3 volts i could scale the numbers more then enough for my needs.
Thanks alot anyway. I bet I will come upp with more stupid questions for you
Re: Reaching 3.3 volt?
There is no such thing as stupid questions, just stupid answers...Jonas wrote:I solved it. I just assumed that the MIC2005A was a 5 volt regulator for the usb port
The problem seems to be that the potentiometer on the joystick dont change its resistance the last few mm's before the end stop. Don't know how to fix that...
I tried with a normal 10K pot and it worked fine, even with 3.3 volts i could scale the numbers more then enough for my needs.
Thanks alot anyway. I bet I will come upp with more stupid questions for you