Your tutorial was really usefull, thank you very much!! I was wondering if a higher baudrate than 9600 would affect the shape of the output signal, but this certainly left no doubt, very clear.
Using a dual or quad comparator such as LM393 LM339 can do this easily. They are open drain design, you can connect any voltage source at the output pin. NPN transistor 2N3904 is current control type, LM393 is logic control type and much power saving for practical design.
Would the transistor level shifting design work efficiently to shift a signal line from 3.3v to 5v for an adressable LED strip like the WS2812b? Just making sure.
Yes and in fact I've used them to drive those LEDs. Those LEDs have a high impedance input and then they amplify the signal and send it to the next LED so you're really just driving One LED. The way to know if the level shifter is going to work on anything is to understand what it's input impedance is. If you have a 1 km resistor as your pull-up for the level shifter and the voltage is 5 volts that means you have about 5 milliamps to drive whatever load you're connected to
What if i want to input a 0v to 5v signal from a car temperature sensor, like oil temp, and it has a scaled reading from 0v to 5v in millivolts. What device can read those 0 to 5v signals and feed it properly to a rpi so it can be 0v to 3.3 scale?
For bidirectional level shifting there some boards based on BSS138 FET with automatic direction sensing, or chips with autodirection sensing like LSF0108. Other option is special I2C digital isolator chips like ADuM1250/ADuM1251. Common digital isolators also can be used for unidirectional level shifting up or down.
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Your tutorial was really usefull, thank you very much!!
I was wondering if a higher baudrate than 9600 would affect the shape of the output signal, but this certainly left no doubt, very clear.
Using a dual or quad comparator such as LM393 LM339 can do this easily. They are open drain design, you can connect any voltage source at the output pin. NPN transistor 2N3904 is current control type, LM393 is logic control type and much power saving for practical design.
Would the transistor level shifting design work efficiently to shift a signal line from 3.3v to 5v for an adressable LED strip like the WS2812b? Just making sure.
Yes and in fact I've used them to drive those LEDs. Those LEDs have a high impedance input and then they amplify the signal and send it to the next LED so you're really just driving One LED. The way to know if the level shifter is going to work on anything is to understand what it's input impedance is. If you have a 1 km resistor as your pull-up for the level shifter and the voltage is 5 volts that means you have about 5 milliamps to drive whatever load you're connected to
Still great!
very nicely explained. thanks
What if i want to input a 0v to 5v signal from a car temperature sensor, like oil temp, and it has a scaled reading from 0v to 5v in millivolts. What device can read those 0 to 5v signals and feed it properly to a rpi so it can be 0v to 3.3 scale?
Very useful.
TKQ
What about bi-directional level shifting for I2C for example?
For bidirectional level shifting there some boards based on BSS138 FET with automatic direction sensing, or chips with autodirection sensing like LSF0108. Other option is special I2C digital isolator chips like ADuM1250/ADuM1251. Common digital isolators also can be used for unidirectional level shifting up or down.
Why did you multiply 5*2 and then divided by 3?
3.3V is two third of 5V. He meant 5 * (2/3). Or 5V * (10K/(5K+10K))