Connecting Altimeter to nrf52 dk using i2c.

Question

Hi I trying to connect Altimeter ( mpl 3115a2) to the nrf52 development kit. Can someone guide me how to do it (pin connection). I have followed the example given in the sdk but still I am a little unclear.
Thank you.

atune · Accepted Answer

In the twi_master_with_twis_slave example the pins and twi/s instances are defined in the file config.h: 
 #define TWI_SCL_M 3 //!< Master SCL pin
#define TWI_SDA_M 4 //!< Master SDA pin

#define MASTER_TWI_INST 0 //!< TWI interface used as a master accessing EEPROM memory
 
 The macros are used in twi_master_init(): 
 const nrf_drv_twi_config_t config =
 {
 .scl = TWI_SCL_M,
 .sda = TWI_SDA_M,
...
 
 So in the example you can change TWI_SCL_M and TWI_SDA_M to be 27 and 26 respectively to match your circuit. 
 The simulated EEPROM (slave) address is also defined in config.h: 
 #define EEPROM_SIM_ADDR 0x50 //!< Simulated EEPROM TWI address
 
 and the address is used like so: 
 static ret_code_t eeprom_read(size_t addr, uint8_t * pdata, size_t size)
 {
...
 ret = nrf_drv_twi_tx(&m_twi_master, EEPROM_SIM_ADDR, &addr8, 1, true);
...
 ret = nrf_drv_twi_rx(&m_twi_master, EEPROM_SIM_ADDR, pdata, size, false);
...
 }
 
 So EEPROM_SIM_ADDR above would in your altimeter's case be changed to 0xC0 ( datasheet p.6. ; 7bit address 0x60 << 1 ). Otherwise the reads and writes are done similarly to how they're done in the example. 
 As for the read/write (register) addresses, you need to follow e.g. the sequence in MPL3115A2 datasheet p.10. IIC_RegWrite/Read are analogous to eeprom_write/read in the example (size=1). 
 I hope I managed to answer your question and didn't just blabber something... :)

Connecting Altimeter to nrf52 dk using i2c.

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