I2C Driver Sample Application

Description

The I2C Driver sample application demonstrates I2C controller/target communication on SR110 in both single-board and double-board setups.

What this sample does:

Initializes I2C and applies controller/target configuration.
Runs transfer flows in either blocking or non-blocking mode.
Supports controller-transmit and target-transmit test directions.
Verifies transferred bytes and prints match/mismatch results in logs.

In single-board mode, controller and target tasks run on the same board for internal loopback-style validation. In double-board mode, one board runs controller mode and the other board runs target mode.

Hardware Requirements

Astra Machina Micro Kit (SR110)

Prerequisites

Choose one setup path:
- CLI: Setup and Install SDK using CLI
- VS Code: Setup and Install SDK using VS Code

Mode Configuration (Important)

Update i2c_sample_app.h before build.

1. Board mode selection

Use only one board mode:

I2C_SINGLE_BOARD_MODE = 1, I2C_DOUBLE_BOARD_MODE = 0 (single-board)
I2C_SINGLE_BOARD_MODE = 0, I2C_DOUBLE_BOARD_MODE = 1 (double-board)

2. Double-board role selection

When I2C_DOUBLE_BOARD_MODE = 1, build separate images:

Controller board image: I2C_CONTROLLER_MODE = 1, I2C_TARGET_MODE = 0
Target board image: I2C_CONTROLLER_MODE = 0, I2C_TARGET_MODE = 1

3. Transfer type selection

Use one transfer type:

NON_BLOCKING_XFER = 1, BLOCKING_XFER = 0
or NON_BLOCKING_XFER = 0, BLOCKING_XFER = 1

4. Transfer direction selection

Use one direction:

CONTROLLER_TRANSMIT = 1, TARGET_TRANSMIT = 0
or CONTROLLER_TRANSMIT = 0, TARGET_TRANSMIT = 1

Connections

Single-board I2C loopback wiring

Connect I2C source pins to I2C target pins on the same board.

RevB:

GPIO_15 (I2C_SCL) -> GPIO_44 (I2C_SCL)
GPIO_16 (I2C_SDA) -> GPIO_45 (I2C_SDA)

RevC and RevE:

GPIO42 (I2C_SCL) -> GPIO_44 (I2C_SCL)
GPIO43 (I2C_SDA) -> GPIO_45 (I2C_SDA)

Double-board wiring

Connect between two boards:

Board-1 SCL -> Board-2 SCL
Board-1 SDA -> Board-2 SDA
Board-1 GND -> Board-2 GND

For double-board mode, ensure both GND pins are connected to maintain proper clock synchronization.

Building and Flashing the Example using VS Code

Use the VS Code flow described in the SR110 guide and the VS Code Extension guide:

Build (VS Code):

Update i2c_sample_app.h macros for required mode.
Open Build and Deploy -> Build Configurations.
Select i2c_sample_app in the Application dropdown.
Build with Build (SDK + App) for the first build, or Build App for rebuilds.

Flash (VS Code):

Use Image Conversion to generate the flash image.
Use Image Flashing (SWD/JTAG) to flash the firmware image.

Building and Flashing the Example using CLI

Use the CLI flow described in the SR110 guide:

SR110 Build and Flash with CLI

Build (CLI):

Update i2c_sample_app.h macros for required mode.

From <sdk-root>/examples, build the example:

cd <sdk-root>/examples
export SRSDK_DIR=<sdk-root>
make cm55_i2c_sample_app_defconfig BOARD=SR110_RDK BUILD=SRSDK

If you need to update config via menuconfig:

make cm55_i2c_sample_app_defconfig BOARD=SR110_RDK BUILD=SRSDK EDIT=1

Flash (CLI):

Activate the SDK venv (required for image generation tools):

# Linux/macOS
source <sdk-root>/.venv/bin/activate
# Windows PowerShell
.\.venv\Scripts\Activate.ps1

Generate the flash image:

cd <sdk-root>/tools/srsdk_image_generator
python srsdk_image_generator.py \
  -B0 \
  -flash_image \
  -sdk_secured \
  -spk "<sdk-root>/tools/srsdk_image_generator/B0_Input_examples/spk_rc4_1_0_secure_otpk.bin" \
  -apbl "<sdk-root>/tools/srsdk_image_generator/B0_Input_examples/sr100_b0_bootloader_ver_0x012F_ASIC.axf" \
  -m55_image "<sdk-root>/examples/out/sr110_cm55_fw/release/sr110_cm55_fw.elf" \
  -flash_type "GD25LE128" \
  -flash_freq "67"

Flash the firmware image:

cd <sdk-root>
python tools/openocd/scripts/flash_xspi_tcl.py \
  --cfg_path tools/openocd/configs/sr110_m55.cfg \
  --image tools/srsdk_image_generator/Output/B0_Flash/B0_flash_full_image_GD25LE128_67Mhz_secured.bin \
  --erase-all

Running the Application using VS Code Extension

Complete the required I2C wiring from the Connections section.
Flash the image and press RESET on the board.
For logging output, click SERIAL MONITOR and connect to the DAP logger port on J14.
- To make it easier to identify, ensure only J14 is plugged in (not J13).
- The logger port is not guaranteed to be consistent across OSes. As a starting point:
  - Windows: try the lower-numbered J14 COM port first.
  - Linux/macOS: try the higher-numbered J14 port first.
- If you do not see logs after a reset, switch to the other J14 port.
Observe I2C configuration logs, transfer completion logs, and match/mismatch results.

Double-board run note

Build and flash controller-mode image to one board and target-mode image to the other board.
Reset both boards after wiring is complete.

Expected Logs

Controller Write

0001666732:[0][WRN][LOGR]:Changing logger interface to LOGGER_IF_CONSOLE
0001781732:[0][INF][SYS ]:Application drivers
initialization complete without errors.
0001883107:[0][INF][SYS ]:SR110 SDK version 1.3.0
0001996986:[0][INF][GENR]:Starting I2C sample app...Target task started
0002101861:[0][INF][GENR]:Controller task started
0002204249:[0][DBG][GENR]:running task for loop 0x3000dfe0
0002305735:[0][INF][USB ]:USB Device Driver task
0002403497:[0][INF][USB ]:USB device unmounted
0002506487:[0][INF][USB ]:USB stopped
0003957107:[0][INF][GENR]:ten_bit_addr: 0,general_call_response:0,scl_stuck_timeout_ms:1,            sda_stuck_timeout_ms:1,target_address:50
0003957107:[0][INF][GENR]:0004121774:[0Target: Readi0004121855:[0][INF][GENR]:Controller target address: 0x32
0004222018:[0][INF][GENR]:Semaphore successfully taken
0004322121:[0][INF][GENR]:Controller: Sending data...
0005560586:[0][INF][GENR]:Write is completed
0005714488:[0][INF][GENR]:[Controller] I2C Event: 0x0
0005818112:[0][INF][GENR]:[Controller] I2C Event: 0x4
0005920614:[0][INF][GENR]:[Target] I2C Event: 0x1
0006029112:[0][INF][GENR]:[Target] I2C Event: 0x4
0006139512:[0][INF][GENR]:0006139512:[0][INF][GENR]:CTarget: Data received:RX[0] = 0x02
0006253498:[0][INF][GENR]:RX[1] = 0x01
0006356015:[0][INF][GENR]:0006356015:[00006356088:[0][INF][GENR]:RX[3] = 0x04
0006455873:[0][INF][GENR]:RX[4] = 0x05
0006568502:[0][INF][GENR]:RX[5] = 0x06
0006672998:[0][INF][GENR]:RX[6] = 0x07
0006778623:[0][INF][GENR]:RX[7] = 0x08
0006879748:[0][INF][GENR]:RX[8] = 0x29
0006985495:[0][INF][GENR]:RX[9] = 0x30
0007086498:[0][INF][GENR]:RX[10] = 0x31
0007185623:[0][INF][GENR]:RX[11] = 0x32
0007301771:[0][INF][HAPI]

Target Write

0001688861:[0][WRN][LOGR]:Changing logger interface to LOGGER_IF_CONSOLE
0001805737:[0][INF][SYS ]:Application drivers
initialization complete without errors
0001919612:[0][INF][SYS ]:SR110 SDK version 1.3.0
0002022116:[0][INF][GENR]:Starting I2C sample app...Target task started
0002129116:[0][INF][GENR]:Controller task started
0002238504:[0][DBG][GENR]:running task for loop 0x3000dfd8
0002353365:[0][INF][USB ]:USB Device Driver task
0002455627:[0][INF][USB ]:USB device unmounted
0002559117:[0][INF][USB ]:USB stopped
0005172865:[0][INF][GENR]:ten_bit_addr: 0,general_call_response:0,scl_stuck_timeout_ms:1,            sda_stuck_timeout_ms:1,target_address:50
0005172865:[0][INF][GENR]:ten_bit_addr: 0,enable_bus_clear:0,clear_stuck_sda:0,            scl_stuck_timeout_ms:1,sda_stuck_timeout_ms:1
0005430377:[0][INF][GENR]:Controller target address: 0x32
0006842213:[0][INF][GENR]:Semaphore successfully takenController: Reading starts...
0006921782:[0][INF][HAPI]:------------------------------------------
0007024131:[0][INF][HAPI]:       Host API Router task
0007125747:[0][INF][GENR]:[Controller] I2C Event: 0x1

0007338743:[0][INF][GENR]:[Target] I2C Event: 0x0
0007438867:[0][INF][GENR]:[Target] I2C Event: 0x4
0007541752:[0][INF][HAPI]:------------------------------------------
0007642253:[0][INF][HAPI]:Active interface is USB
0007753269:[0][INF][GENR]:0007753269:[0][INF][GENR]:CNon-Blocking read success with event type: 1
Non-Blocking read success with event type: 1
0Read byte [0]: 0x02
0007962151:[0][INF][GENR]:Non-Blocking target write with event type: 4
00008177285:[0][INF][GENR]:Read byte [2]: 0x03
0008275380:[0][INF][GENR]:Read byte [3]: 0x04
0008377005:[0][INF][GENR]:Read byte [4]: 0x05
0008477754:[0][INF][GENR]:Read byte [5]: 0x06
0008587879:[0][INF][GENR]:Read byte [6]: 0x07
0008693879:[0][INF][GENR]:Read byte [7]: 0x08
0008803505:[0][INF][GENR]:Read byte [8]: 0x29
0008905379:[0][INF][GENR]:Read byte [9]: 0x30
0009009379:[0][INF][GENR]:Read byte [10]: 0x31
0009122755:[0][INF][GENR]:Read byte [11]: 0x32