adding I2C to asset_tracker_v2 in V2.5.0

[Timothy]

I have V2.5.0 asset_tracker_v2 running on a nrf9160DK board. I need to add I2C capability. I tried copying the code from the i2c_api example. I added "CONFIG_I2C=y" to prj.conf. I added the following to the overlay file:

/ {
aliases {
i2c-0 = &i2c0;
};
};

I get the following error when I try to compile the asset_tracker_v2. I have tried changing to i2c-1,i2c-2 and I still get the same error. what am I doing wrong? How do I add I2C capability to asset_tracker_v2 and what pins are the I2C signals (SCL/SDA) available?

In file included from C:/Nordic1/v2.5.0/zephyr/include/zephyr/toolchain.h:50,
from C:/Nordic1/v2.5.0/zephyr/include/zephyr/kernel_includes.h:19,
from C:/Nordic1/v2.5.0/zephyr/include/zephyr/kernel.h:17,
from C:/Nordic1/v2.5.0/zephyr/soc/arm/nordic_nrf/validate_enabled_instances.c:7:
C:/Nordic1/v2.5.0/zephyr/include/zephyr/toolchain/gcc.h:81:36: error: static assertion failed: "Only one of the following peripherals can be enabled: SPI2, SPIM2, SPIS2, TWI2, TWIM2, TWIS2, UARTE2. Check nodes with status \"okay\" in zephyr.dts."
81 | #define BUILD_ASSERT(EXPR, MSG...) _Static_assert(EXPR, "" MSG)
| ^~~~~~~~~~~~~~
C:/Nordic1/v2.5.0/zephyr/soc/arm/nordic_nrf/validate_enabled_instances.c:51:1: note: in expansion of macro 'BUILD_ASSERT'
51 | BUILD_ASSERT(CHECK(2), MSG(2));
| ^~~~~~~~~~~~
[119/466] Building C object zephyr/CMakeFiles/zephyr.dir/subsys/logging/log_core.c.obj
ninja: build stopped: subcommand failed.
FATAL ERROR: command exited with status 1: 'C:\Nordic1\toolchains\c57af46cb7\opt\bin\cmake.EXE' --build 'C:\Nordic1\test_n160\asset_tracker_v2\build'

************zephyr.dts******************

aliases {
led0 = &led0;
led1 = &led1;
led2 = &led2;
led3 = &led3;
pwm-led0 = &pwm_led0;
sw0 = &button0;
sw1 = &button1;
sw2 = &button2;
sw3 = &button3;
bootloader-led0 = &led0;
mcuboot-button0 = &button0;
mcuboot-led0 = &led0;
watchdog0 = &wdt0;
spi-flash0 = &mx25r64;
i2c-0 = &i2c0;
ext-flash = &mx25r64;
};

i2c0: i2c@8000 {
compatible = "nordic,nrf-twim";
#address-cells = < 0x1 >;
#size-cells = < 0x0 >;
reg = < 0x8000 0x1000 >;
clock-frequency = < 0x186a0 >;
interrupts = < 0x8 0x1 >;
status = "disabled";
};
i2c1: i2c@9000 {
compatible = "nordic,nrf-twim";
#address-cells = < 0x1 >;
#size-cells = < 0x0 >;
reg = < 0x9000 0x1000 >;
clock-frequency = < 0x186a0 >;
interrupts = < 0x9 0x1 >;
status = "disabled";
};
i2c2: arduino_i2c: i2c@a000 {
compatible = "nordic,nrf-twim";
#address-cells = < 0x1 >;
#size-cells = < 0x0 >;
reg = < 0xa000 0x1000 >;
clock-frequency = < 0x61a80 >;
interrupts = < 0xa 0x1 >;
status = "okay";
pinctrl-0 = < &i2c2_default >;
pinctrl-1 = < &i2c2_sleep >;
pinctrl-names = "default", "sleep";
pcal6408a: pcal6408a@20 {
compatible = "nxp,pcal6408a";
status = "disabled";
reg = < 0x20 >;
gpio-controller;
#gpio-cells = < 0x2 >;
ngpios = < 0x8 >;
int-gpios = < &gpio0 0x6 0x11 >;
};
};
i2c3: i2c@b000 {
compatible = "nordic,nrf-twim";
#address-cells = < 0x1 >;
#size-cells = < 0x0 >;
reg = < 0xb000 0x1000 >;
clock-frequency = < 0x186a0 >;
interrupts = < 0xb 0x1 >;
status = "disabled";
};

[Timothy]

if I enable CONFIG_I@C=y in the prj.conf file I get the error message about only one device allowed. 

[Timothy]

If I do exactly what you said earlier in this ticket I get the following error message. This was trying to use i2c0 as you suggested. so far  nothing seems to work with merging I2C into asset_tracker. I am confused.

-- Found devicetree overlay: C:/Nordic1/test_n160/asset_tracker_v2/boards/nrf9160dk_nrf9160_ns_0_14_0.overlay
devicetree error: 'pinctrl-0' is marked as required in 'properties:' in C:/Nordic1/v2.5.0/zephyr/dts/bindings\i2c\nordic,nrf-twim.yaml, but does not appear in <Node /soc/peripheral@40000000/i2c@8000 in 'C:/Nordic1/v2.5.0/zephyr/misc/empty_file.c'>
-

[Naeem Maroof]

Hello Timothy,

I started with the Asset Tracker V2 sample from NCS 2.5.0, and I modified prj.conf to add the config for i2c and then I edited the overlay file as shown below. I am enabling only i2c2 as you have asked and also I am using pin 30 and 31. (You can see both files in the image below)

Compilation was successful without any issue. Copying below the content which I updated in the overlay: We are enabling i2c2 and using Pinctrl to define the pins for data and clock.

&i2c2 {
	status = "okay";
	pinctrl-0 = <&i2c2_default>;
	pinctrl-1 = <&i2c2_sleep>;
	pinctrl-names = "default", "sleep";
};

&pinctrl {
	i2c2_default: i2c2_default {
		group1 {
				psels = <NRF_PSEL(TWIM_SDA, 0, 30)>,
						<NRF_PSEL(TWIM_SCL, 0, 31)>;
		};
	};

	i2c2_sleep: i2c2_sleep {
		group1 {
				psels = <NRF_PSEL(TWIM_SDA, 0, 30)>,
						<NRF_PSEL(TWIM_SCL, 0, 31)>;
				low-power-enable;
		};
	};
};

/Regards, Naeem

[Timothy]

I have attached my overlay file. I must be adding your code in the wrong place. I copied it and pasted it inside the existing overlay file. I have also added code for UART2 in there needed for BLE operation. what am I doing wrong?

I see the following errors when I try to compile.

-- Found BOARD.dts: C:/Nordic1/v2.5.0/zephyr/boards/arm/nrf9160dk_nrf9160/nrf9160dk_nrf9160_ns.dts
-- Found devicetree overlay: C:/Nordic1/v2.5.0/zephyr/boards/arm/nrf9160dk_nrf9160/nrf9160dk_nrf9160_ns_0_14_0.overlay
-- Found devicetree overlay: C:/Nordic1/test_n160/asset_tracker_v2/boards/nrf9160dk_nrf9160_ns.overlay
-- Found devicetree overlay: C:/Nordic1/test_n160/asset_tracker_v2/boards/nrf9160dk_nrf9160_ns_0_14_0.overlay
devicetree error: C:/Nordic1/test_n160/asset_tracker_v2/boards/nrf9160dk_nrf9160_ns.overlay:90 (column 1): parse error: expected node name, property name, or '}'
-
2364.nrf9160dk_nrf9160_ns.overlay

[Naeem Maroof]

Timothy said:

C:/Nordic1/test_n160/asset_tracker_v2/boards/nrf9160dk_nrf9160_ns.overlay:90 (column 1): parse error: expected node name, property name, or '}'

There is a missing   };   on line number 89,

and an extra   };   on line 114.

Please remove it from line 114 and put at line 89