Use this forum to chat about hardware specific topics for the ESP8266 (peripherals, memory, clocks, JTAG, programming)

User avatar
By AJITnayak
#78179 Dear all,
This is my first thread in this forum. I am using Nodmecu unit from amica and Arduino 1.8.5.
I am trying to interface nodemcu with Modbus RTU device. When i connect Tx and rx line The device works normally.There is no issue in communication

Problem i am facing while communicating while restart of nodemcu or power off to power on.During this situation device wont come online itself. If i remove the tx and rx line if it restart/ Reset device start communicating . it start receive response when device tx and rx line connected. during this stage i wont get any problem in communication.

How can i overcome this issue. as product i wanna sale.It wont work at all unlsess tx and rx line are isolated. Some application where tx and rx lines used as digitalo it wont lead any problems.
User avatar
By QuickFix
#78209 You are aware that the RX and TX pins on the NodeMCU are also directly connected to the on board RS232 - USB convertor?