TWI : Is there a Nordic sample app that uses twi_hw_master.c

RE: TWI : Is there a Nordic sample app that uses twi_hw_master.c

Mahendra Tailor — Sun, 17 Nov 2013 11:47:30 GMT

The attached scope traces show what I mean about the ACK from the slave after the address is sent not going down low enough.

RE: TWI : Is there a Nordic sample app that uses twi_hw_master.c

Bastiaan — Sun, 17 Nov 2013 11:43:53 GMT

I incorporated twi_hw_master.c in my app and it works. That code polls the EVENT_TXDSENT bit

My own code, seems to do all the same preperation work but instead of polling EVENT_TXDSENT it enables irq and then waits for a flag that the irq handle sets.

In my irq scheme the ACK from the slave is not going down low enough implying that the S0D1 is not functioning when the address is written.

I must be doing something wrong but cannot understand what.

RE: TWI : Is there a Nordic sample app that uses twi_hw_master.c

Guest — Sun, 17 Nov 2013 11:43:53 GMT

I incorporated twi_hw_master.c in my app and it works. That code polls the EVENT_TXDSENT bit

My own code, seems to do all the same preperation work but instead of polling EVENT_TXDSENT it enables irq and then waits for a flag that the irq handle sets.

In my irq scheme the ACK from the slave is not going down low enough implying that the S0D1 is not functioning when the address is written.

I must be doing something wrong but cannot understand what.

RE: TWI : Is there a Nordic sample app that uses twi_hw_master.c

Mahendra Tailor — Sat, 16 Nov 2013 12:43:46 GMT

When I write data to a slave using the TWI peripheral (my driver based on code from twi_hw_master.c) the ACK from the slave does not go all the way down to the same level as when I read and the nrf is ACKing the data to the slave.

In desperation, I have changed my code so that it calls the helper functions in twi_sw_master.c and this time I see that the ACK from the same slave goes down as low as an ACK from the nrf.

My next step is take twi_hw_master.c and use helper functions in there and see if I see any changed behaviour. I still cannot find any Nordic sample apps that use twi_hw_master.c

Will keep you updated.

I wonder why Nordic provided twi_sw_master.c which bit-bangs in the first place !!

RE: TWI : Is there a Nordic sample app that uses twi_hw_master.c

Bastiaan — Sat, 16 Nov 2013 11:16:57 GMT

Is there a way of uploading a screen snapshot of a scope? What I see is that when I read 4 bytes from a slave, the ack from the slave does not go all the way down as far as when the ack's are sent by the master for the read bytes.

RE: TWI : Is there a Nordic sample app that uses twi_hw_master.c

Guest — Sat, 16 Nov 2013 11:16:57 GMT