Arduino supporting NXP wifi module

Projects General Guidance
1

Dear all

I am trying to build IOT application using Arduino IDE platform. Initially i have tested with nodemcu and its working fine. I found few limitation while using nodemcu

  1. If i am trying to communicate with Modbus RTU device ,If TX and RX line connected if power off & on . Communication stop working

  2. Library supported by modbus only give integer value . if End module is 32 bit and read response in 32 bit format i wont get response . The End RS485 module should be converted to read data in Integer format

Is there any other wifi module in NXP ,Qualcom which supporting Arduino Ide and get raid of above issues.

2
  1. what physical line for Modbus RTU? RS232, RS495? how did you wire it?
  2. Modbus only uses 32bit registers. it is in the standard. use 32 bit type (short, unsigned shot, uint32_t,...)
3

https://www.nxp.com/products/identification-and-security/nfc/nfc-reader-ics/development-kits-for-pn7150-plugn-play-nfc-controller:OM5578

https://www.nxp.com/products/identification-and-security/authentication/om3710-a71chard-a71ch-arduino-compatible-development-kit:OM3710-A71CHARD

Is anyone worked on above. specification say arduino compatible.

I have used RS232 keeping request and response in modbus format. I used Nodemcu TX-> Energy meter RX and nodemcu Rx-> Energy meter TX. I used below library
http://en.trialcommand.com/blog/arduino-master-esp8266-slave-modbus-rtu-ttl/

Major issue for me is first one . If TX and Rx line get connected. If Energy meter 3V3 tapped to nodemcu power . if energy meter turn off and turn on Device wont reintiate Or Wifi router is turned off and restart again it wont communicate

4

TTL Serial is not RS232. did you use a "RS232 to TTL Serial" adapter?