V
VK3YNV
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Here are Denys’s VK3ZYZ’s mods for adding LSB to Codan Radios that only have USB support.
http://sadarc.org/files/CodanSSBMod.zip
http://sadarc.org/files/CodanSSBMod.zip
There is a new PCB on the way for this, thanks to a lot of help from Josh. This is the first PCB I've had assembled by JLCPCB so I'm looking forward to seeing how it goes.
One thing that is different is the use of an ATtiny processor, and they have an interesting one pin programming feature.
In this video, he has a resistor from TXD to RXD while some others use a Schottky diode, as I have used.
There is a SMT diode under the yellow heat shrink at the PCB pins.
On my new PCB that is coming, the 3 holes for the programmer have the center one offset so the pins have a friction fit when pushed in. No soldered connection is needed. Not my original idea, but copied from a Microchip prto board.
The pins labeled "P + G" at the bottom of the PCB.
One thing that is different is the use of an ATtiny processor, and they have an interesting one pin programming feature.
There is a SMT diode under the yellow heat shrink at the PCB pins.
On my new PCB that is coming, the 3 holes for the programmer have the center one offset so the pins have a friction fit when pushed in. No soldered connection is needed. Not my original idea, but copied from a Microchip prto board.
The pins labeled "P + G" at the bottom of the PCB.
No joy so far 
I cannot drive the Si5351 for some reason.
For a test, I added the I2C connector...
(It is a bit twisted)
Then added an OLED display and programmed the I2C scanner to the board.
The OLED shows up, 0x3C and the Si5351 does too, 0X60.
so I do not know what the problem is.
I've tested the TCXO and it is running at 25Mhz ok.
To be continued........
I cannot drive the Si5351 for some reason.
For a test, I added the I2C connector...
(It is a bit twisted)
Then added an OLED display and programmed the I2C scanner to the board.
The OLED shows up, 0x3C and the Si5351 does too, 0X60.
so I do not know what the problem is.
I've tested the TCXO and it is running at 25Mhz ok.
To be continued........
I got it going
So I made up the leads on the other boards and programmed them.
No go
Well, it turns out, the "working" one is a test setup with an added OLED display. When that is unplugged, the board no longer works.
I FORGOT THE PULLUPS!!!!
Here is the bodge fix.
EDIT:
A better placement is on the I2C connector pads.
Some clear fingernail polish over the resistors helps protect them and I added some clear heat shrink tube for wire support.
So I made up the leads on the other boards and programmed them.
No go
Well, it turns out, the "working" one is a test setup with an added OLED display. When that is unplugged, the board no longer works.
I FORGOT THE PULLUPS!!!!
Here is the bodge fix.
EDIT:
A better placement is on the I2C connector pads.
Some clear fingernail polish over the resistors helps protect them and I added some clear heat shrink tube for wire support.
Last edited:
internal pull ups too weak? or does it not have internal pull ups?I got it going
View attachment 3820
So I made up the leads on the other boards and programmed them.
No go
Well, it turns out, the "working" one is a test setup with an added OLED display. When that is unplugged, the board no longer works.
I FORGOT THE PULLUPS!!!!
View attachment 3821
Here is the bodge fix.
