Arduino not running code without connection to PC via USB I have an Arduino UNO and esp8266 connected to it. Both devices has separate power lines. Each connected via USB cable, for Arduino USB used as power line and standard firmware uppload line, for esp8266 only as power suppli line. If I connect all to computer's USB ports, everything working fine. But, if I connect Arduino to separate charger that has USB port, then Arduino not running code. I can see it by Serial interface work, because code using it intensively, and when I'm turning Arduino on the RX and TX lines are down all the time, that I think indicates, that code is not running, and Arduino in boot mode, somehow.

I've made a search through same issues and nothing helped from theirs suggestions. I tried to pull RX line to GND through resistor, to make sure that there are no noise on the line, added capacitors for power supply line, to make exclude pulsations on the line. But nothing helped.

Arduino not running code independently from esp8266. I tried to run Arduino separately, without any other connections, but it not helped. Still not running.
Have you made sure that the ground of both the arduino as well as esp8266 are connected together? Also since you are using esp8266 you must have connected it to rx and tx pins. Make sure you remove it while uploading the code and connect it afterwards.