Dear all,
I connected the LPC55S28-EVK to the proximity sensor VCNL4200. The LPC55S28-EVK is configured as master and VCNL4200, of course, as slave.
I developed a simple software to read the DeviceID of the sensor: in an endless while I inserted the reading of the DeviceID of the sensor
int i =0;
while(1) {
i++ ;
/* 'Dummy' NOP to allow source level single stepping of
tight while() loop */
__asm volatile ("nop");
int res= readID();
PRINTF("%3d %x\n",i,res);
}
the readID funcrion is:
#define EXAMPLE_I2C_MASTER FLEXCOMM4_PERIPHERAL
#define I2C_MASTER_SLAVE_ADDR_7BIT VCNL4200_I2CADDR
#define I2C_DATA_LENGTH 2
uint8_t g_master_txBuff[I2C_DATA_LENGTH];
uint8_t g_master_rxBuff[I2C_DATA_LENGTH];
int readID() {
int ID;
//if (readData(VCNL4200_DeviceID_REG) != 0x1058)
ID=readData(VCNL4200_DeviceID_REG);
return ID;
}
uint16_t readData(uint8_t command_code) {
uint8_t deviceAddress;
deviceAddress=command_code;
status_t reVal = kStatus_Fail;
if (kStatus_Success == I2C_MasterStart(EXAMPLE_I2C_MASTER, I2C_MASTER_SLAVE_ADDR_7BIT, kI2C_Write))
{
reVal = I2C_MasterWriteBlocking(EXAMPLE_I2C_MASTER, &deviceAddress, 1, kI2C_TransferNoStopFlag);
if (reVal != kStatus_Success)
{
return -1;
}
reVal = I2C_MasterRepeatedStart(EXAMPLE_I2C_MASTER, I2C_MASTER_SLAVE_ADDR_7BIT, kI2C_Read);
if (reVal != kStatus_Success)
{
return -1;
}
reVal =I2C_MasterReadBlocking(EXAMPLE_I2C_MASTER, g_master_rxBuff, I2C_DATA_LENGTH, kI2C_TransferDefaultFlag);
if (reVal != kStatus_Success)
{
return -1;
}
reVal = I2C_MasterStop(EXAMPLE_I2C_MASTER);
if (reVal != kStatus_Success)
{
return -1;
}
}
return g_master_rxBuff[1]<<8 | g_master_rxBuff[0];
}I used MCUXpresso IDE v11.5.1 [Build 7266] [2022-04-13] and the routine readData is developed according the i2c_polling_b2b_master.c example.
According the datasheet of VCNL4200 VCNL4200_I2CADDR is 0x51 and VCNL4200_DeviceID_REG id 0x0E.
I connected the proximity sensor to the demo board as following:
I2C_SCL P17-1 I2C_SCL P17-1
I2C_SDA P17-3 I2C_SDA P17-3
GND P17-7 GND P17-7
and I used P16-8 (3.3V) as power supply of the proximity sensor.
I compiled the software and I debugged it but the data displayed on the console is:
Hello World
1 ffff
2 1058
3 ffff
only three readings are made and only the second one is correct.
After the third reading the program hangs-up in the routine I2C_PendingStatusWait.
Did you have a similar problem ?
How did you fix it ?
Thank you very much for your help and cooperation.
Best regards.
