IC22S Arduinoized?

VK3ZYZ

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It is not much warmer inside as our central aircon is dead. But at least I have a hot coffee!

The next step will be to remove the optos used as level shifters to make the Arduino drive the PLL leads direct as I originally tried.
Following advice fom multiple folk, I did take the PLL board out and resolder some joints so the first try may have been ok but for a PLL board fault. Watch this space to find out.
 

VK3BLD

New member
I did resolder some joints on the PLL board and actually had a contact with VK3YYY
The setup needs a bit of fixing....
View attachment 1369
But it works :)
There are optos added to drive the PLL lines with around 7V, 9V - the LED drop. You always need LEDs!
I still have to find a good spot to feed +9V to the Arduino on TX so it can detect the duplex. But I have no experiance with the IC-22S circuit up to now. Cupper time and maybe a movie ;)
EDIT: The purple wire is the TX lead to the Arduino and this spot works :)
It is the "TM" connection. So far, I do not know if it is J5, J6 or J8. And it maybe some other one. I'll look into it later.
View attachment 1370
In my original design I fed the outputs of the Eprom directly to the feed point, so it ran happily on 5v
 

VK3ZYZ

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As I have the optos in circuit at the moment, before they are removed, I think it could be interesting to run a variable supply to them and see just how low the voltage can be and still have the PLL work. reliable 3.3V operation would be nice!
 

VK3ZYZ

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The Arduino is now driving the PLL directly. After testing it looks to be a min of 4.2V drive on the PLL lines before it drops put so 5V is ok but 3.3V is not. So, using an ARM for instance, would requite level shifting.
Another mod is to feed the Arduino power from the HI/Off/LOW switch via an 1N400x diode
PowerFeedDiode.jpg

and 1000uF cap. This diode and cap is because the original setup using the 9V directly would reset the Arduino as it switched between HI and LOW.
PowerFeedCap.jpg


Just as an aside, it appears the IC-22S is less troubled by the interference generated by my solar panels and inverters. This looks good as now I can run a 2M radio in the house during the daylight :)

And it looks like there is still a dry joint on one of the steel feed through pins that I've not replaced as it occasionally drops out of lock and a "technical tap" fixes it. So, a good going over all the PLL board solder joints is a good idea, not just a few as I did earlier.
 
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VK3ZYZ

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I was having problems with the TRX line selected as it would go low if the PLL dropped out of lock so toggling the Arduino between TX and RX again.
So, the code has been changed for an active LOW for TX and the feed is now the mic PTT line, picked up from the slate wire attached to the TX lamp on this tag strip behind the front panel. The TRX wire to the Arduino is the pinkish one.
PTT_Line.jpg

EDIT: There are 3 "pinkish" wires I see. The one in question shares the tag with the white wire.
 

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VK3ZYZ

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Something died in the offset circuit so I removed a couple of chips and linked the pins direct to the PLL chip inputs.
I now goes fine. The duplex offset circuit is not the same as the circuit diagram so this was the easiest fix.
Photo on 20-07-2022 at 8.19 PM.jpg


EDIT: See post #35 that explains what the problem was.
 
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VK3ZYZ

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I have had a go at EasyEDA and here it is so far...
IC22S_EasyEDA.jpg

EDIT: I've added a cap (C4) for filtering of the CTCSS waveform. This is the circuit of the PCB I've just sent away to get made. The connector types are not correct as I had trouble finding the ones I use, so ignore that.
 
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VK3ZYZ

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VK3ZYZ Arduino IC22S.jpg

My version of a PCB but using McCAD as it just quicker and easier for me.
This is pretty rough but it will do I think for an hours work.
 
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VK3ZYZ

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The boards have just arrived :)
BoardsHaveArrived.jpg

They arrived :)

The only error is the PCB is a couple of mm too long, and the mounting hole is in the wrong place too.
A board snip and slot work with a file fixed it. An M3 M/F pillar of about 14mm fits.
ArduinoIC22S_BoardR2R.JPG

EDIT: OOPS! I have swapped the 10K and 20K resistors in the R2R network in the original photo, so here it is fixed.
Maybe I should follow the circuit????
But the CTCSS is a bit rough. A couple of changes are R1 =10k and C4 = 100nF. Still a work in progress!

I've not got a trim pot for the CTCSS as yet.
ArduinoBoardBtm.JPG

And cleaning the flux off would make it look better!

The PTT line to the Arduino board connects here, behind the front panel.
PTT_Line.jpg


and the power is from here.
PowerToArduinoBoard.JPG


Make sure you load the code from post #25. I loaded an earlier one and was bamboozled for a time until I remembered the PTT sense is now TX =
LOW.
And it works :)

EDIT: The CTCSS is injected via a 10K resistor to the PCB pa the white of the shielded mic cable connects to. The orange wire is it.
CTCSS_Injection.JPG
 
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VK3ZYZ

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I originally thought some ICs were damaged in the duplex circuitry, but as Ray, VK3YNV has found, the problem is the 5V out from the Arduino can drive the PLL chip ok, but is just not reliably enough for the CMOS chips in the duplex circuit.
What I did was to remove them and run the top 5 PLL lives from the header pins to the PLL chip directly.
PLL_Wire_Links.jpg

This is a recommended mod to make, and something like this has had to be done in the 3 IC22S sets that have been done so far.
It does seem to be mainly the 4030 chip that plays up, but I just removed both chips that feed the PLL.

Thanks Ray.

EDIT: A thought Ray just came up with is to lower the supply to the duplex chips a little and that could work too.
 
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VK3ZYZ

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I have now modded 2 sets and both go well.
Here is an updated circuit and a modification guide and the fixed code.
I had the CTCSS 1/10 the frequency needed as I'd modded an earlier file and forgot to fix both parts. IC22S_20220913.zip is the file to use for the CTCSS table version.
VK3ZYZ_Arduino_IC22S_V2_cct.jpg

EDIT: This circuit has a fix and includes the CTCSS mod mentioned below. And a PDF is in the next post.
Also, the encoder labels are now correct. A new version of the 3D printed front has 2 push buttons inset for more features.
 

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VK3ZYZ

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I am working on a new front piece, in fact, there will be 2 to suit both sizes of the OLED displays. Included will be a couple of push buttons so that they can be used to select the CTCSS tone for example.
FrontV3.jpg

Watch this space for updates.
 

VK3ZYZ

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NOTE! Not all OLEDs are created equal. The pin-out is not the same across them all so make sure you check the connections!.
I just got trapped myself (again)!
 
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