simpleRTK2B Heading + ESP32 NTRIP — no data from TX2

Hardware
1

I’m using an ArduSimple simpleRTK2B Heading Basic Starter Kit with an ESP32-S3. My goal is RTK-corrected absolute position from NTRIP while retaining the two-antenna heading solution.

Current wiring:

  • Heading kit powered from 5V_IN
  • Common GND
  • ESP32 3.3V → IOREF
  • simpleRTK2Blite TX2 → ESP32 RX
  • simpleRTK2Blite RX2 ← ESP32 TX

On the Lite, u-center VALGET shows:

  • CFG-UART1-ENABLED = 1
  • CFG-UART1-BAUDRATE = 115200
  • CFG-UART1OUTPROT-NMEA = 1
  • CFG-MSGOUT-NMEA_ID_GGA_UART1 = 1

The ESP32 UART passes a loopback test, but it receives zero bytes from TX2 at 115200.

Has anyone successfully used this Heading kit with an ESP32 as the NTRIP client?

1. Is TX2/RX2 the correct pair for receiving absolute-position GGA from the Lite and sending external RTCM3 corrections back to it while retaining heading?

2. If so, what exact UART settings are required on the Lite for GGA OUT and RTCM3 IN simultaneously?

If you have actually done this with an ESP32/F9P heading setup, I’d especially appreciate your wiring and configuration.

2

Note that the Arduino format F9P from Ardusimple has a weird naming for the tx2 rx2 labels. They’re inverted.

Maybe it’s your issue?

3

Thanks Pat. ArduSimple has now confirmed that:

TX2 = simpleRTK2B Lite TX1
RX2 = simpleRTK2B Lite RX1

They also confirmed it is safe for the ESP32 to drive RX2 because there is circuitry between the Lite and Budget connections.

We still get zero bytes from TX2 on the ESP32 at 115200, although the ESP32 UART loopback works.

For anyone running this Heading kit successfully with an ESP32:

Does the factory Heading configuration actually output GGA on the Lite UART1/TX2 pin, or did you have to change the Lite configuration first?

Also, for NTRIP corrections into RX2, do you have RTCM3X input enabled on Lite UART1?

If possible, could you tell us the exact UART1 IN/OUT settings you’re using?