Yahoo !!
what server where ? Normally speaking the completion of reception will be clear because you have received a complete frame.
The supply voltage sets the input logic levels.
For 3.3V, Vih = 2V and Vil = 0.8V but the input can be 5V or 3.3V levels.
The voltage conneced to the 4.7K resistor set the output voltage.
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I am talking about the configuration 2, that when external device sends data and ESP receives it, the ESP will now then have to transmit the data to a server (it will be on a software side because I have to code it)
Thanks, I understood now that the supply at the output pin is what sets the output voltage.
having this in series, this negate the inverting of signal output, is this correct?
The basic idea is correct but some of the resistors should not be there.
I'll draw new schematics for you
Let me again remind you that if both input and output signals should be inverted, you can simply swap the A & B lines over, so the extra transistor and mosfet are overcomplete (as they were already but that is a different matter)
What server ? over wifi ? again if the message has been completely sent you should be able to determine this from the received data.
Thanks for providing this schematic, just wanna ask how were you able to select those value of resistors?
Does it mean once I swap the A & B lines the input signal from external device is inverted, so I only need one transistor/mosfet for level shifting, right?
yes it does. you will also invert the output in the process. What a transceiver does is that when in 'drive' mode, it converts a Logic HIGH into A = Vcc & B = GND and logic LOW into B = Vcc & A = GND, (the polariity may be the opposite, don't pin me on that) and when in 'receive' mode it converts A = Vcc & B = GND into Logic HIGH and B = Vcc & A = GND into logic lOW. So simply swapping the A & B lines over on 1 of the transceivers inverts the signal.
The idea of the transceivers output is that particularly when A & B lines are in a twisted pair, the magnetic filed created by the spirals, counteracts the capacitance of the cable making it possible to get a better speed to cable length ratio that 2is less susceptible to noise than with a normal connection.
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I suggest you read a few tutorials on how transistors and MOSFETs work.
Some things used in the calculations:
The transistor Hfe
The transistor Vbe(sat)
The transistor Ic
The transistor Ib
MOSFET Gate charge
MOSFET Vgs
MOSFET Rds
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