"Undefined Reference" on the linker level

[Connie Violet]

Hi. I am a beginner with nrf52832. Trying to get Bluetooth and UART and a I2C peripheral working at the same time. I had a working version of the I2C peripheral and UART working together and tried to merge Bluetooth in, referencing the ble_app_uart example provided in nRF5_SDK_12.3.0. Currently when I try to do make flash I do not get any compiling errors, but I am getting linker errors that say that I have "undefined reference":

Linking target: _build/nrf52832_xxaa.out
_build/nrf52832_xxaa_twi.c.o: In function `twi_master_init':
/home/yilunsheng/src/accelerometer, SDK12.3, app_uart_merge/./twi.c:43: undefined reference to `nrf_drv_twi_init'
/home/yilunsheng/src/accelerometer, SDK12.3, app_uart_merge/./twi.c:46: undefined reference to `nrf_drv_twi_enable'
_build/nrf52832_xxaa_lis3dh.c.o: In function `lis3dh_read_data':
/home/yilunsheng/src/accelerometer, SDK12.3, app_uart_merge/./lis3dh.c:171: undefined reference to `nrf_drv_twi_tx'
/home/yilunsheng/src/accelerometer, SDK12.3, app_uart_merge/./lis3dh.c:180: undefined reference to `nrf_drv_twi_rx'
_build/nrf52832_xxaa_lis3dh.c.o: In function `lis3dh_init':
/home/yilunsheng/src/accelerometer, SDK12.3, app_uart_merge/./lis3dh.c:232: undefined reference to `nrf_drv_twi_tx'
collect2: error: ld returned 1 exit status
../nRF5_SDK_12.3.0/components/toolchain/gcc/Makefile.common:153: recipe for target '_build/nrf52832_xxaa.out' failed
make: *** [_build/nrf52832_xxaa.out] Error 1

Very confused about where the problem is.

[Jørgen Holmefjord]

Hi,

This is caused by one of (or both) the following things:

1. You have not included the source file that implements the functions in your project. In SDK 12.3.0, these functions are implemented in the source file 'nRF5_SDK_12.3.0_d7731ad\components\drivers_nrf\twi_master\nrf_drv_twi.c'
2. You have not enabled the module in your project's sdk_config.h file. Check if you can find TWI_ENABLED in the file, and set it to 1. If you cannot find this section in the sdk_config.h file in the BLE project, you need to copy the entire section related to the TWI master driver from one of the TWI master projects and add it to the sdk_config.h file of your BLE project.

// <e> TWI_ENABLED - nrf_drv_twi - TWI/TWIM peripheral driver
//==========================================================
#ifndef TWI_ENABLED
#define TWI_ENABLED 1
#endif
#if  TWI_ENABLED
// <o> TWI_DEFAULT_CONFIG_FREQUENCY  - Frequency
 
// <26738688=> 100k 
// <67108864=> 250k 
// <104857600=> 400k 

#ifndef TWI_DEFAULT_CONFIG_FREQUENCY
#define TWI_DEFAULT_CONFIG_FREQUENCY 26738688
#endif

// <q> TWI_DEFAULT_CONFIG_CLR_BUS_INIT  - Enables bus clearing procedure during init
 

#ifndef TWI_DEFAULT_CONFIG_CLR_BUS_INIT
#define TWI_DEFAULT_CONFIG_CLR_BUS_INIT 0
#endif

// <q> TWI_DEFAULT_CONFIG_HOLD_BUS_UNINIT  - Enables bus holding after uninit
 

#ifndef TWI_DEFAULT_CONFIG_HOLD_BUS_UNINIT
#define TWI_DEFAULT_CONFIG_HOLD_BUS_UNINIT 0
#endif

// <o> TWI_DEFAULT_CONFIG_IRQ_PRIORITY  - Interrupt priority
 

// <i> Priorities 0,2 (nRF51) and 0,1,4,5 (nRF52) are reserved for SoftDevice
// <0=> 0 (highest) 
// <1=> 1 
// <2=> 2 
// <3=> 3 
// <4=> 4 
// <5=> 5 
// <6=> 6 
// <7=> 7 

#ifndef TWI_DEFAULT_CONFIG_IRQ_PRIORITY
#define TWI_DEFAULT_CONFIG_IRQ_PRIORITY 7
#endif

// <e> TWI0_ENABLED - Enable TWI0 instance
//==========================================================
#ifndef TWI0_ENABLED
#define TWI0_ENABLED 1
#endif
#if  TWI0_ENABLED
// <q> TWI0_USE_EASY_DMA  - Use EasyDMA (if present)
 

#ifndef TWI0_USE_EASY_DMA
#define TWI0_USE_EASY_DMA 1
#endif

#endif //TWI0_ENABLED
// </e>

// <e> TWI1_ENABLED - Enable TWI1 instance
//==========================================================
#ifndef TWI1_ENABLED
#define TWI1_ENABLED 0
#endif
#if  TWI1_ENABLED
// <q> TWI1_USE_EASY_DMA  - Use EasyDMA (if present)
 

#ifndef TWI1_USE_EASY_DMA
#define TWI1_USE_EASY_DMA 0
#endif

#endif //TWI1_ENABLED
// </e>

// <e> TWI_CONFIG_LOG_ENABLED - Enables logging in the module.
//==========================================================
#ifndef TWI_CONFIG_LOG_ENABLED
#define TWI_CONFIG_LOG_ENABLED 0
#endif
#if  TWI_CONFIG_LOG_ENABLED
// <o> TWI_CONFIG_LOG_LEVEL  - Default Severity level
 
// <0=> Off 
// <1=> Error 
// <2=> Warning 
// <3=> Info 
// <4=> Debug 

#ifndef TWI_CONFIG_LOG_LEVEL
#define TWI_CONFIG_LOG_LEVEL 3
#endif

// <o> TWI_CONFIG_INFO_COLOR  - ANSI escape code prefix.
 
// <0=> Default 
// <1=> Black 
// <2=> Red 
// <3=> Green 
// <4=> Yellow 
// <5=> Blue 
// <6=> Magenta 
// <7=> Cyan 
// <8=> White 

#ifndef TWI_CONFIG_INFO_COLOR
#define TWI_CONFIG_INFO_COLOR 0
#endif

// <o> TWI_CONFIG_DEBUG_COLOR  - ANSI escape code prefix.
 
// <0=> Default 
// <1=> Black 
// <2=> Red 
// <3=> Green 
// <4=> Yellow 
// <5=> Blue 
// <6=> Magenta 
// <7=> Cyan 
// <8=> White 

#ifndef TWI_CONFIG_DEBUG_COLOR
#define TWI_CONFIG_DEBUG_COLOR 0
#endif

#endif //TWI_CONFIG_LOG_ENABLED
// </e>

#endif //TWI_ENABLED
// </e>

If you had spent 1 minute searching DevZone for the errors you are experiencing, you would have found countless other questions answering how to solve this issue.

Best regards,
Jørgen

[Connie Violet]

Hi, Jorgen. I did checked and made sure that this part in my sdk_config.h look the same as what you pasted here but it did not solve the problem, and that was why I made this post.