IridiumSBD I2C and SparkFun u-blox library conflict with RockBLOCK 9603

[adamgarbo]

Hi there,

It appears that the IridiumSBD I2C and SparkFun u-blox libraries are conflicting when using a SparkFun Qwiic Micro and RockBLOCK 9603 over serial.

Components used:

• SparkFun Qwiic Micro
• RockBLOCK 9603

Steps to reproduce:
This can be observed by running any of the Serial_Examples__Rockblock with u-blox library included:
#include <SparkFun_Ublox_Arduino_Library.h>

After adding the library, for instance using Example5_Sleep, results in error 5, no modem detected:

Output:

Starting modem...
17:00:50.165 -> Calling internalBegin
17:00:50.165 -> Powering on modem...
17:00:50.653 -> >> AT

17:00:50.653 -> AT
Waiting for response OK
17:00:50.653 -> 
17:00:50.653 -> << >> AT

17:01:20.638 -> AT
Waiting for response OK
17:01:20.638 -> 
17:01:20.638 -> << >> AT

17:01:55.728 -> AT
Waiting for response OK
17:01:55.728 -> 
17:01:55.728 -> << >> AT

17:02:25.826 -> AT
Waiting for response OK
17:02:25.826 -> 
17:02:25.826 -> << >> AT

17:02:51.716 -> AT
Waiting for response OK
17:02:51.716 -> 
17:02:51.716 -> << >> AT

17:03:20.631 -> AT
Waiting for response OK
17:03:20.631 -> 
17:03:20.631 -> << >> AT

17:03:50.650 -> AT
Waiting for response OK
17:03:50.650 -> 
17:03:50.650 -> << >> AT

17:04:20.630 -> AT
Waiting for response OK
17:04:20.630 -> 
17:04:20.630 -> << No modem detected.
17:04:50.639 -> Powering off modem...
17:04:50.639 -> Begin failed: error 5
17:04:50.639 -> No modem detected: check wiring.

Potential cause:

I believe this is because the u-blox library defines Serial as SerialUSB:
https://github.com/sparkfun/SparkFun_Ublox_Arduino_Library/blob/97bd455b0e7a05b92bfe5a528c28cc47f2e2d289/src/SparkFun_Ublox_Arduino_Library.h#L55-L67

However, on the Qwiic Micro, we use Serial as the port for the RockBLOCK:

#define IridiumSerial Serial
IridiumSBD modem(IridiumSerial, SLEEP_PIN);
IridiumSerial.begin(19200);

It doesn't seem to matter what order the definitions are made, the u-blox library seems to have final say as to what Serial will be. I wonder if a possible solution is to have a check in the u-blox library for the Qwiic Micro, and not declare Serial as SerialUSB.

Cheers,
Adam

[adamgarbo]

Confirmed that commenting line 63 in the u-blox library resolves this issue with the Qwiic Micro:

https://github.com/sparkfun/SparkFun_Ublox_Arduino_Library/blob/97bd455b0e7a05b92bfe5a528c28cc47f2e2d289/src/SparkFun_Ublox_Arduino_Library.h#L63

Will create an issue on the u-blox library repo but leave this issue open until it's resolved over there.

[PaulZC]

Hi Adam (@adamgarbo ),

Thanks for finding this!

Instead of using the problematic #define, you can just use:

IridiumSBD modem(Serial, SLEEP_PIN);
Serial.begin(19200);

But I don't think that will solve the problem...? Could you test this please? I suspect to fix this completely we will need to change the way we define Serial as SerialUSB in the u-blox library.
All the best,
Paul

[adamgarbo]

Fixed by sparkfun/SparkFun_Ublox_Arduino_Library#151