Hi folks. I've got a working circuit working into the Arduino Uno with a component needing 5v (transmitter) and one needing 3.3v (sensor). I'm trying to move it to a circuit board with just the Atmega328 chip. My power supply provides 9v and am using the 7805 voltage regulator to drop to 5v. My question is how can I get 3.3v to the component that requires it. I've searched around and thought using a voltage divider (10k/20k) would get me 3.3v. But someone said you cannot do that since the 3.3v would be a reference only. Then I read about buck converters and wondering if I can use that to drop 5v to 3.3v.
I've attached a rough diagram.
I'm a newbie as you can probably tell. This is a real project I need to put together so any help would be greatly appreciated. I'd appreciate any guidance on wiring up the solution if possible.
What is the component that requires 3.3v? In any case you can try the voltage divider, it might work or not, but surely won't hurt anything. Otherwise you can use a proper level shifter chip, such as the CD4504.
Be aware that you don't just need to power the sensor at 3.3v, but also drive the (single?) communication pin at that voltage. The voltage divider/level shifter is needed on the communication pin, to power the sensor you can use the 3.3v regulator that most Arduinos have onboard. See the 3.3V pin?
One last alternative, if you want to use a bare 328, would be to power the 328 itself at 3.3v.
Sorry...didn't mean to doublepost...thought I had worded the issue different with more detail. Just that other people might see my question who might otherwise not see it and have run up against the same issue and have a solution...still searching for answer as research seems conflicting. The Tx component operates a minimum of 3.7v so I read although it seems to operate at 3.3v but at a much reduced range. I've ordered a buck converter but not sure if/how it will help. Is cheap enough though.
Seems that it would be a common problem though. Someone even suggested putting a red LED inline with the sensor as it drops the voltage 1.5v or so...
