ESP8266 Community Forum

- Fri Jun 03, 2016 3:34 pm #48528 In esptool.py

Code: Select all""" Try connecting repeatedly until successful, or giving up """
    def connect(self):
        print 'Connecting...'

        for _ in xrange(4):
            # issue reset-to-bootloader:
            # RTS = either CH_PD or nRESET (both active low = chip in reset)
            # DTR = GPIO0 (active low = boot to flasher)
            self._port.setDTR(False)
            self._port.setRTS(True)
            time.sleep(0.05)
            self._port.setDTR(True)
            self._port.setRTS(False)
            time.sleep(0.05)
            self._port.setDTR(False)

But I am only connect to the USB to Serial adapter. I don't have RTS or DTR signal on the USB adapter connected my PC.

- Fri Jun 03, 2016 3:46 pm #48530 In this case, you will have to manually placing the ESP in Upload mode by bringing temporarily the GPIO0 to GND and doing a reset or power recycling.

- Fri Jun 03, 2016 7:16 pm #48539

In this case, you will have to manually placing the ESP in Upload mode by bringing temporarily the GPIO0 to GND and doing a reset or power recycling.

So you saying only reset will a serial connection be made with Rom? That piece of code with DTS or RTS only for system that has a serial port not for the usb 2serial adapter.

- Fri Jun 03, 2016 8:58 pm #48541 The DTR/RTS mechanism is simply ease the Upload process in such way that you don't have to manually handle it on modules such NodeMCU or Wemos-D1-Mini where they have USB-TTL built-in with this DTR/RTS wiring done.

For plain ESP connections, you have to handle GPOI0 and RES manually ...