Hello,
I am working with the S32K144EVB-Q100 evaluation board and trying to scan for I2C slave devices using the LPI2C peripheral (LPI2C0) at 100 kHz in S32 Design Studio with the S32 SDK.
I implemented a simple I2C scanning logic that checks addresses from 0x08 to 0x77 and prints the results through UART, but the scanner is not detecting any connected I2C slave device even though the hardware connections seem correct and pull-up resistors are present.
I would like to confirm whether this is the correct approach for detecting devices using the LPI2C driver or if there is a recommended method for implementing an I2C scanner on this platform.
Additionally, while checking the documentation for the S32K144EVB, I noticed that the I2C pins PTA2 (LPI2C0_SDA) and PTA3 (LPI2C0_SCL) appear to be routed to multiple connectors such as J1, J2, and J4.
Because of this, I am unsure which connector should be used when connecting an external I2C slave device.
Could someone please clarify which connector is the recommended header for accessing LPI2C0 SDA and SCL on the board, whether an external I2C device can be connected to any of these connectors, and if there are any jumpers or board configuration settings that must be enabled for these pins to function correctly as I2C?
Any guidance would be greatly appreciated.
Hi,
your scanning method (sending START + address + checking for ACK) is a standard approach and should work using LPI2C. The lack of ACK usually points to:
- Wrong wiring, lack of pull ups
- Wrong device address
- The device not powered
- The board not actually using the pins you think it is (common with EVB alternate routing)
Try to measure bus line with scope/analyzer to see bytes are sent and have slave addresses you expect.
Within SDK you need to call LPI2C_DRV_MasterSetSlaveAddr to set new slave address for any subsequent I2C communication, otherwise it will use the one set in configuration.
Regarding a board connection. You can simply to check its schematic to realize which header should be used.
You can see PTA2/PTA3 are connected to J1.1/J1.3
BR, Petr
