I am trying to connect an MCU (esp32-wroom-32ue) to a LTE modem Quectel BG95 and I am trying to decide. I am using the UART connection to send AT commands.
- Which connections are necessary?
- What pins on the ESP32 correspond to DTR, DCD, RI, CTS, and RTS.
-pretty sure that RTS and CTS are GPIO 14 and 15 respectively but have seen some conflicting information on this.
The datasheet is below and a picture from the hardware integration guide of the modem shows all of the connections being made but not all of the functionalities are mentioned. Just RXD, TXD, CTS and RTS.
The hardware integration document gives the following explanation:
The module provides three UART interfaces: the main UART, debug UART and the GNSS UART interfaces. The main UART interface supports 9600, 19200, 38400, 57600, 115200, 230400, 460800 and 921600 bps baud rates, and the default is 115200 bps. It is used for data transmission and AT command communication, and supports RTS and CTS hardware flow control. The default frame format is 8N1 (8 data bits, no parity, 1 stop bit). The debug UART interface supports a fixed baud rate of 115200 bps, and is used for software debugging and log output. The GNSS UART interface supports 115200 bps baud rate by default, and is used for GNSS data and NMEA sentences output.