NEO-M8U with Arduino DUE Native USB port.

Qwiic System
1

When running the “example 3_getposition” some reason I get the “Ublox GPS not detected at default I2C address. Please check wiring. Freezing.” only with the DUE NATIVE USB port connected.

With the programming port I have no issue with either Wire1 or Wire ports.

Any ideas why?

The whole reason to use the DUE if for it NATIVE USB and CAN ports on board.

SparkFun Ublox Example

Lat: 0 Long: 0 (degrees * 10^-7) Alt: 0 (mm) SIV: 0

Lat: 0 Long: 0 (degrees * 10^-7) Alt: 0 (mm) SIV: 0

Lat: 0 Long: 0 (degrees * 10^-7) Alt: 0 (mm) SIV: 0

Lat: 0 Long: 0 (degrees * 10^-7) Alt: 0 (mm) SIV: 0

Lat: 0 Long: 0 (degrees * 10^-7) Alt: 0 (mm) SIV: 0

Thanks

Bruce

2

I think I fixed part of the issue. I can get it to work fine with Wire by lengthening the default wait time to 2000. But still can not get is to work with the Wire1. I am using 1.5K pull ups to 3.3V(like the DUE Wire port) and I have removed all of the other pullups but still can not get it to communicate with the M8U QWIIC board. I can get it to communicate with the QWIIC EEPROM and the 4X20 RBG LCD but not the M8u.

Any thoughts?

3

In Example 3 I replaced myGPS.begin() with myGPS.begin(Wire1,(uint8_t)0x42) as per the header begin(TwoWire &wirePort = Wire, uint8_t deviceAddress = 0x42)and Wire.begin(); with Wire1.begin(); as necessary for Wire1 vs Wire

4

Ok, so it works with Wire and the Serial and SerialUSB and Wire1 and Serial but not Wire1 and SerialUSB. Any ideas?

5

OK, this even gets more strange. If I have the while (!Serial); I get:

SparkFun Ublox Example

Ublox GPS not detected at default I2C address. Please check wiring. Freezing.

If I comment it out: //while (!Serial);

Lat: 0 Long: 0 (degrees * 10^-7) Alt: 0 (mm) SIV: 0

Ideas?

6

Not sure what’s causing this, but we’ve experienced all sorts of weird behavior on the I2C bus on the Due. You might try switching to a different board like an Uno to see if that clears things up.

7

bvernham:
OK, this even gets more strange. If I have the while (!Serial); I get:

SparkFun Ublox Example

Ublox GPS not detected at default I2C address. Please check wiring. Freezing.

If I comment it out: //while (!Serial);

Lat: 0 Long: 0 (degrees * 10^-7) Alt: 0 (mm) SIV: 0

Ideas?

Hi,

I am having the same problem and I was wondering if you were able to fix the issu.

Thanks

8

Wow, I wish I could remember. In the long run I am using UART to communicate with the GPS’s to minimize latency.