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Topic: What i am doing wrong in this PCB drawing? (Read 162 times) previous topic - next topic

martinius96

Hello, I did last time in the Eagle program 4 years ago. I would like to make a PCB board which is very simple, there will be: LCD display 20x4, I2C converter, RFID reader RC522, Arduino Nano, or future AtMega328. I downloaded various parts that are not given in standard libraries. The LCD display may seem to be a must, however?
Wiring:

It would be enough for the I2C converter to make that design. On the RFID reader I found it to be quite different (mirrored). Here is the second question .. When I draw it, does it mean I look at these modules from above? I'm a little overwhelmed ...
I came out of this design (RFID reader I mirrored inverted) grid I set to 1.27mm. Has anyone managed to dismantle, position, or see a problem somehow?
PCB:

It should only be a single board as a prototype and later I want to replace the Nano for the AtMega328 with an internal oscillator. The principle is just reading a few keys (22pcs) and measuring time (stopwatch).

And I'm going to display it .. I imagine so that the transducer there from the back of the board and display front .. It should work this way, or I would get those I2C pins from the converter pulled on some pins on the PCB and they would go to A4 A5 ..

CrossRoads

Is 150mA enough current for the RFID board?
Does it need 3.3V level signals? If yes, add a cd74HC4050 powered with 3.3V to do the conversion.
74AHC125 powered with 5V to buffer the 3.3V signals back to 5V to the processor.

SDA/SCL will need 4.7K pullup resistors.
Designing & building electrical circuits for over 25 years.  Screw Shield for Mega/Due/Uno,  Bobuino with ATMega1284P, & other '328P & '1284P creations & offerings at  my website.

MORE-PCB

You can send Eagle file  .brd  to  sales@morepcb.com  for quick view and quotation.

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