[KurtE]

There are times when a sketch wants to know how many Wire objects there are. Example wire scanner app.

In the MBED wire library this was defined as WIRE_HOWMANY

So simply defined it from DT_NODE_HAS_PROP(DT_PATH(zephyr_user), i2cs)

Here is an example sketch, that can make use of it. Note: I put more or less the same zephyr stuff in it, such
that it does it on it's own.
zephyr_wire_scanner-261020a.zip

[github-actions]

Built 1.0.1-0.pr.706.261020t1528z+ga894004c

CI run PASSED 🟢

Artifact	Board	Core	Tests	RAM	Sketches	Warnings	Errors
✅ zephyr_contrib	ek_ra8d1	2 🏷️	✅	12.0%	2	-	-
	frdm_mcxn947	7 🏷️	✅	53.4%	2	-	-
	frdm_rw612	3 🏷️	✅	74.6%	2	-	-
✅* zephyr_main	giga	10 🏷️	✅*	45.9%	86	2	-
	nano33ble	5 🏷️	✅	79.2%	44	-	-
	nano_connect	6 🏷️	✅*	69.5%	38	8	-
	nano_matter	3 🏷️	✅	⚠️ 86.5%	22	-	-
	nicla_sense	3 🏷️	✅	⚠️ 89.0%	18	-	-
	nicla_vision	11 🏷️	✅	40.4%	68	-	-
	opta	11 🏷️	✅	42.3%	76	-	-
	portentac33	6 🏷️	✅	⚠️ 100.0%	72	-	-
	portentah7	10 🏷️	✅*	51.2%	102	2	-
✅ zephyr_unoq	unoq	2 🏷️	✅	43.5%	56	-	-
	ventunoq	5 🏷️	✅	23.7%	48	-	-

Legend

Board	Test	Status description
🔥	🔥	Test run failed to complete.
❌	🔴	Test completed with unexpected errors.
⁉️	⁉️	Test was expected to fail but passed; exception entry is outdated.
✔️*	🚫	Test completed with errors, but all are known/expected.
✅*	🟡	Test completed with some warnings; no errors detected.
✅	🟢	Test passed successfully, with no warnings or errors.
🌑	🌑	Test was skipped.

[pennam]

Hi @KurtE, thanks for the contribution!

In addition to your changes, could we also remove the WIRE_HOWMANY definition in the nano_connect variant and add a fallback to arduino_i2c? This would keep it consistent with the approach used in Wire.cpp

diff --git a/libraries/Wire/Wire.h b/libraries/Wire/Wire.h
index 49ca362..ac8c331 100644
--- a/libraries/Wire/Wire.h
+++ b/libraries/Wire/Wire.h
@@ -93,4 +93,13 @@ DT_FOREACH_PROP_ELEM(DT_PATH(zephyr_user), i2cs, DECLARE_EXTERN_WIRE_N)
 extern arduino::ZephyrI2C Wire;
 #endif
 
+/* Number of Wire instances, matching the instantiation logic in Wire.cpp */
+#if DT_NODE_HAS_PROP(DT_PATH(zephyr_user), i2cs)
+#define WIRE_HOWMANY DT_PROP_LEN(DT_PATH(zephyr_user), i2cs)
+#elif DT_NODE_EXISTS(DT_NODELABEL(arduino_i2c))
+#define WIRE_HOWMANY 1
+#else
+#define WIRE_HOWMANY 0
+#endif
+
 typedef arduino::ZephyrI2C TwoWire;
diff --git a/variants/arduino_nano_connect_rp2040/variant.h b/variants/arduino_nano_connect_rp2040/variant.h
index 66281ed..fd1614e 100644
--- a/variants/arduino_nano_connect_rp2040/variant.h
+++ b/variants/arduino_nano_connect_rp2040/variant.h
@@ -97,8 +97,6 @@ static const uint8_t SCK  = PIN_SPI_SCK;
 
 // Wire (I2C)
 // ----------
-#define WIRE_HOWMANY        (1)
-
 #define PIN_WIRE_SDA        (18u)
 #define PIN_WIRE_SCL        (19u)

[KurtE]

Pushed up the changes...
I don't have the connect to test it, but compiled

[github-actions]

Built 1.1.0-rc1.pr.706.261021t1448z+g89548ac0

CI run FAILED: 🔥 giga, 🔥 nano_matter, 🔥 nicla_vision, 🔥 unoq, 🔥 ventunoq, 🔥 ek_ra8d1

Artifact	Board	Core	Tests	RAM	Sketches	Warnings	Errors
🔥 zephyr_contrib	ek_ra8d1	🔥	Core build failed!
	frdm_mcxn947	7 🏷️	✅	53.4%	2	-	-
	frdm_rw612	8 🏷️	✅	73.4%	2	-	-
🔥 zephyr_main	giga	🔥	Core build failed!
	nano33ble	5 🏷️	✅	79.2%	44	-	-
	nano_connect	6 🏷️	✅	69.5%	38	-	-
	nano_matter	🔥	Core build failed!
	nicla_sense	3 🏷️	✅	⚠️ 89.0%	18	-	-
	nicla_vision	🔥	Core build failed!
	opta	11 🏷️	✅	42.3%	76	-	-
	portentac33	6 🏷️	✅	⚠️ 100.0%	72	-	-
	portentah7	10 🏷️	✅*	51.2%	100	2	-
🔥 zephyr_unoq	unoq	🔥	Core build failed!
	ventunoq	🔥	Core build failed!

Legend

Board	Test	Status description
🔥	🔥	Test run failed to complete.
❌	🔴	Test completed with unexpected errors.
⁉️	⁉️	Test was expected to fail but passed; exception entry is outdated.
✔️*	🚫	Test completed with errors, but all are known/expected.
✅*	🟡	Test completed with some warnings; no errors detected.
✅	🟢	Test passed successfully, with no warnings or errors.
🌑	🌑	Test was skipped.

Caution

zephyr_contrib is blocked due to failures on ek_ra8d1!

Caution

zephyr_main is blocked due to failures on giga, nano_matter, nicla_vision!

Caution

zephyr_unoq is blocked due to failures on unoq, ventunoq!