无法使用Explorer 16/32 mcp2221a接口芯片

我已经能够连接USB到串行适配器到我的DSPIC33 FJ128GP804 PIM，并发送字符到TyTalm会话。我的USB到串行适配器连接到处理器上的PIN 37，但是，当我使用我的范围来测量在Explorer 16/32上的PIN 50的信号时，我什么也看不见。PIM顶部的跳线位于UART位置。我还尝试删除跳线J37、J38、J42和J42，以确保没有设置错误。谢谢，史葛。



      以下为原文

    I've been able to connect a USB to serial adapter to my dsPIC33FJ128GP804 PIM, and transmit characters to a Teraterm session.  My USB to serial adapter is connected to pin 37 on the processor,  However, when I use my scope to measure signals at pin 50 on the Explorer 16/32, I don't see anything.  The jumper on the top of the PIM is in the UART position.  I've also tried removing the jumpers J37, J38, J42, and J42 to make sure that nothing was set incorrectly.
Thanks in advance,
Scott