Develop interface and mobile app with arduino to read/write modbus registers from board and show messages on a display

Hello sir, I have experience in designing electronics circuits and can make your project. i will make your project completely on my side and will deliver a working prototype. I can also develop hardware compatible android and windows based apps. I can show you my previous experience on similar projects. If you wish we can discuss in chat. Thanks

hi you need do it with arduino nano: how you will write values to registers ,do you will use keypad or will connect many buttons to board? in project header you say need a mobile app too , so do you need it wifi or gsm module with arduino ? if you need it wifi with screen we suggest : option one : using esp8266-12e + modbus Rs485 module + oled screen 64X 32 or bigger option two: using raspberry pi b3 + modbus Rs485module + 7" touchscreen anyway we have excellent experience in working on modbus rtu and programming hmi screens with qt/qml/c++ and we can provide and demo for free as proof of concept price will be according choice system . but will not lower than 1000$

I DO NOT OUTSOURCE I have been a freelancer for the past 8 years, I believe that my experience and skill in this background will prove to be of great help to you. Contact me to discuss more on the details