Uno R4 WiFi with Sparkfun Qwiic OpenLog and RTC freezing with 'Wire1'

Qwiic System
1

Hi There,

We are using the Sparkfun Qwiic 20x4 SerLCD; LCD-16398, Sparkfun Qwiic OpenLog; DEV-15164 and Sparkfun Qwiic Real Time Clock Module; RV-8803. All modules function fine with the Sparkfun PLUS/RedBoard with Qwiic port; DEV-15123.

However, with the Uno R4 WiFi Qwiic (not Rev.2) only the SerLCD functions properly, both the OpenLog and RTC Freezes.

As per Arduino recommendations, the secondary I2C port, ‘Wire1’, is stated in the code:

Wire1.begin();

lcd.begin(Wire1);

myLog.begin(Wire1);

rtc.begin(Wire1);

As mentioned the SerLCD works fine with this change, but the OpenLog and RTC will not accept the 2nd ‘Wire1’ port call:

"error: no matching function for call to ‘OpenLog::begin(TwoWire&)’ myLog.begin(Wire1); "

Wondering if anyone has some ideas what to try here, I suspect the OpenLog and RTC library may require editing for the Uno R4 WiFi?

Thank you,

Sean

2

Are they all on the same i2c bus? You’ll need to disable all but one set of pull-up resistors on the sensors/devices sharing a bus

3

For the QWIIC openlog do begin like: myLog.begin( QOL_DEFAULT_ADDRESS, Wire1);

It expects you to set the address first and you can use the default address, then select the Wire1.

The RTC library will accept rtc.begin(Wire1);

That said TS-Russell is right, make sure to only have pull-up resistors on ONE of the devices, ideally the one at “the end of the line”, to get the best result.

4

Thank you for your excellent assistance.

The added s/w component of ‘QOL_DEFAULT_ADDRESS’ to the Wire1 of the ‘myLog.begin’ ( myLog.begin( QOL_DEFAULT_ADDRESS, Wire1) ) enabled full function of the system. The system functions fine with all pull-ups in tact; however, given the recommendations both here and at ‘sparkfun.com/tutorials/qwiic-single-relay-hookup-guide’, removing all the pull-ups except one pair at the end of the Qwiic chain has been performed.

Again, thank you for your exceptional community support!

Regards,

Sean

https://learn.sparkfun.com/tutorials/qw … e-overview