ESP8266 Community Forum

- Thu May 17, 2018 1:55 pm #75966 I am having trouble working out how to connect a NMEA unit to my ESP8266 12F. The NMEA unit is an Automatic Identification System (for marine use). My receiver unit gives its data out through a Micro USB port.
I'm struggling to work out which wire to connect to the ESP unit. There are four wires that I have available, +5V, GND, D+ and D-
Which wire should I use to connect to the RX of the ESP or do I need to do something to the USB D+ and D- before I connect to the RX of the ESP.

- Thu May 17, 2018 8:21 pm #75967 D+ and D- are not compatible with Rx and Tx. USB is not a serial protocol.

Even if you had a serial to USB converter for the ESP you still would have the problem of neither one acting as the host device. (as a computer does)

You can't connect a USB memory stick to an ESP12. Just because they are both USB connected device doesn't mean that they can operate together.

What you need is a NMEA device with serial output. Then you only need to consider the electrical signal levels.

- Fri May 18, 2018 1:58 am #75969 aaahhhmm, I don't like too simplified answers.
Ofcourse UniversalSerialBus is a serial protocol, as are i2c, SPI and rs232.
But they are not compaible in any way.

And for direct coupling USB devices, this is not possible; not unlike i2c where there are master and slave devices. And your nmea or nodemcu can both be considdered "slaves".

- Fri May 18, 2018 2:51 am #75970 If USB is your only choice of interface then a Raspberry Pi ZeroW may be a better choice of controller for collecting the data as it has built in usb port.

Searching internet shows several examples of using Pi to collect NMEA data.