Topics

Sda, scl

Charlie Crapotta, NA2CC <pccmd@...>
 

Guys,
I am trying to figure out why my Si5351 output at pin 7 is only DC.
In receive ‘mode’, inputting a 7MHz signal from signal generator, what should the SDA and SCL signals be on the Atmega ?
CC

Dave Benson
 

Charlie-

I'll ask- again- if it ever worked before re-flashing the memory.

During receive, SDA and SCL are always high.  They change only on the transitions between Rx and Tx.  There are two bursts of serial data and clock signals during the changeover. Each burst takes 5-6 milliseconds and there are two of them- back ti back.  The way to check them is to turn the Tune knob and verify a burst on both signal lines with each tuning step. 

It also wouldn't hurt to retouch the solder connections on pin 7.  In two places: atop the Si5351 board and underneath the main board.

- Dave, K1SWL


On Mon, Jan 7, 2019 at 11:05 AM Charlie Crapotta, NA2CC <pccmd@...> wrote:
Guys,
I am trying to figure out why my Si5351 output at pin 7 is only DC.
In receive ‘mode’, inputting a 7MHz signal from signal generator, what should the SDA and SCL signals be on the Atmega ?
CC

Charlie Crapotta, NA2CC <pccmd@...>
 

Dave,
As I had mentioned, I did not try before flashing. 
I did retouch but will recheck.
TU
CC

Charlie Crapotta, NA2CC <pccmd@...>
 

Oh, and I did reflash with the original code file which I had backed up before the flash, and it made no difference. 
So I will recheck my connections 

Dave Benson
 


Charlie-

Let's back up a step.  Is there anything on pin 6?  All the time?... or only in Transmit?

Here's what it should do:

pin 7 has a 12.2 MHz signal during receive and a DC voltage during transmit.
pin 6 has a 7 MHz signal during transmit and a DC voltage during receive.

Only pin 6 or pin 7 - but not both- should be active at any given time.

- Dave


On Mon, Jan 7, 2019 at 1:12 PM Charlie Crapotta, NA2CC <pccmd@...> wrote:
Oh, and I did reflash with the original code file which I had backed up before the flash, and it made no difference. 
So I will recheck my connections 

Charlie Crapotta, NA2CC <pccmd@...>
 

Dave,
OK....SDA is LOW on Rx here, though CLK is High
CC

Dave Benson
 

Charlie-

They should both be high.

- Dave


On Mon, Jan 7, 2019 at 8:32 PM Charlie Crapotta, NA2CC <pccmd@...> wrote:
Dave,
OK....SDA is LOW on Rx here, though CLK is High
CC