[General] I2C communication Reading from a Temperature sensor LM75.

[root2hell]

i am trying to read temp sensor LM75(7 bit Slave addr=0x48) that support I2C from a microprocessor mpc8308 using evaluation kit i.e. mpc8308rdb.

I have initialized i2c module by writing FDR Resistor, I2CCR resistor with (Enable i2c module,Disable interrupt, Transmit mode, Broadcast disabled).

then in i2c_read :
1.i2c start condition
2.updating I2CDR with 7 bit addr + W_bit(0x90)
3.wait for ACK by thermal sensor by monitoring SR[RXAK] then
4.send Register addr (0x00)
5.wait for ACK by thermal sensor by monitoring SR[RXAK] then
6.updating I2CDR with 7 bit addr + R_bit(0x91)
7. Put master in Receive mode by clearing I2CCR[MTX] bit.
8. read_data=I2CDR;

But i am only getting 0xFF in read_data byte.

 

[udayan92]

Can you share the code please?

 

[root2hell]

here is the zipped file of source code.

 

[ud23]

i am not familiar with your micro controller but you can see this reference example.

https://www.mikroe.com/forum/viewtopic.php?f=10&t=22478