PIC18F46J50引脚RB1和RB2上的意外行为

我的板应该使用引脚RB1和RB2，每个读取按钮按下。为此，我通过一个100K电阻将每个引脚连接到3V3电源线。这两个按钮然后“接地”在电阻器和PIC引脚之间的相应馈电。课本上的东西。我发现插脚总是按压读。一个多表检查显示，每个引脚上的电压大约是1V65，而不是我预期的3V3。在100K电阻之前，万用表读取一个稳定的3V3，所以很明显有东西在拉低电压。最后，作为最小功能测试，我只配置了数字、输出和高电平的引脚。为此，我绝对期望在引脚上看到3V3，但它仍然是1V65。如果情况可能不同的话，我使用PIC18LF46J50。还有一些额外的配置我忽略了吗？谢谢。



      以下为原文

    My board is supposed to use pins RB1 and RB2 to each read a button press. For this I have each pin tied to the 3V3 power line via a 100K resistor. The two buttons then "ground" the corresponding feed between the resistor and the PIC pin. Textbook stuff.

I found that the pins are always reading as pressed. A multi-meter check reveals that the voltage on each pin is around 1V65 rather than the 3V3 that I was expecting. The multi-meter reads a steady 3V3 BEFORE the 100K resistor, so clearly something is pulling the voltage down.

Finally, as a minimum function test I merely configured the pins for digital, output and high. For this I would definitely expect to see 3V3 on the pins, but it is still 1V65.

Just in case it might make a difference I am using the PIC18LF46J50 .

Is there some additional configuration that I have overlooked?

Thanks.

    ANCON1bits.PCFG8 = 1; /* Set RB2/AN8 for digital not analogue */
    ANCON1bits.PCFG10 = 1; /* Set RB1/AN10 for digital not analogue */
   
    INTCON2bits.RBPU = 1; /* Disable pull-up resistors just in case */
   
    TRISBbits.TRISB2 = 0; /* Set pins for output */
    TRISBbits.TRISB1 = 0;
   
    LATBbits.LATB2 = 1; /* Set pin output = high */
    LATBbits.LATB1 = 1;
   
    /* Now I would expect to see 3V3 on the pins but something
     * is dragging down the voltage */