RE: (nrf51822-EK) How to read twi Multiple Byte ?

aworks — Mon, 12 Jan 2015 15:58:06 GMT

I solved this problem. Thank you

RE: (nrf51822-EK) How to read twi Multiple Byte ?

Stian Røed Hafskjold — Mon, 12 Jan 2015 13:49:42 GMT

The twi_master_transfer() function you refer to is a part of the TWI peripheral driver and is documented here: developer.nordicsemi.com/.../a00769.html

Here you can see that it takes an argument, data_length, which specifies how many bytes that should be transferred from the data array.

In the twi_master_transfer() function (in twi_sw_master.c) you can see that it will not continue to clock out bytes if twi_master_clock_byte() returns false. This function returns false if it does not receive an ACK bit from the slave:

// Read ACK/NACK. NACK == 1, ACK == 0
transfer_succeeded &= !(TWI_SDA_READ());

You should have a logic analyzer in order to be able to debug the TWI bus.