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Hot!PIC16F1827 - UART 3.3V

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2021/03/09 01:21:18 (permalink)
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PIC16F1827 - UART 3.3V

Does this PIC support 3.3 UART? My external module supports only 3.3V level UART.
 
Or is there anyway to use 3.3V UART without adding transistor buffers?
 
Thanks
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    paulfjujo
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    Re: PIC16F1827 - UART 3.3V 2021/03/09 02:55:42 (permalink)
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    hello,
      
    Yes, you can supply your MCU with 3,3V power supply ..
    and use a prolific cable LTTL (3,3V level UART Side) .. USB 
    real test OK with 16F1847 ..
     
    if MCU is powered by 5V, you can add a resistor divider on MCU TX output 
    ie:  Output -- 1k  + 2,2K --Gnd
    signal accross 2,2K ->  RX  interface LTTL/USB  to reduce TX voltage 
    ..  and  use a direct link for MCU RX <-> TX  interface LTTL/UB
    #2
    oliverb
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    Re: PIC16F1827 - UART 3.3V 2021/03/09 03:06:00 (permalink)
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    Depending on what else you are doing with it you could just run the PIC from 3.3V and get compatibility that way.
     
    If you do need the PIC to run from 5V then you need to determine if your module is "5v tolerant", meaning that its input can withstand 5V from the PIC. Many can as it is a common problem. If not then a resistor voltage divider might work, something like 20K series 10K to ground, giving a 3:2 reduction.
     
    In the other direction a 3.3V signal to a 5V PIC USART is going to be technically out of spec as the input is "CMOS" but will probably work anyway, at least at low speeds.
     
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    Re: PIC16F1827 - UART 3.3V 2021/03/09 03:48:24 (permalink)
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    OK thanks.
     
    In simply If I give 3.3V to this PIC then I can directly connect to the modules UART.
     
    If I stick with 5V PIC then a resistor divider on PIC UART (TX) and a two transistor level shifter on modules TX side..!!
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    Re: PIC16F1827 - UART 3.3V 2021/03/09 16:39:17 (permalink)
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    Just to know this PIC will work 3.3 UART if I give power 3.3V.

    But will it work with PIC16F628A when giving supply 3.3V?
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    blue_led
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    Re: PIC16F1827 - UART 3.3V 2021/03/09 16:57:11 (permalink)
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    KARMa
     
    post edited by blue_led - 2021/03/09 16:59:16

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    Re: PIC16F1827 - UART 3.3V 2021/03/09 20:30:04 (permalink)
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    Looks Likes the old PIC16F628A works UART @ 3.3 Levels. I need 9600bps/4Mhz.
    #7
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