Oops was using avrdude 5.5 - updated to 6.3 and it works fine.
Module also working now!
FWIW I got this kit from Thonk 3 weeks ago so might need to check their kits 
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Update on my situation!
After many months of being too busy I finally took another look at this. I reprogrammed the ATMEGA chip and it verified OK. I replaced the 4046 with a 74HC4046 (exact part match). Unfortunately Iām still having no luck, so Iāve ordered another Cadet 1 board AND a replacement ATMEGA to try out in the original board, and will give that a go.
Could you please clear this up for us, @creatorlars? Iād very much prefer using IC sockets for repairability, but wouldnāt want performance to suffer.
I have some minor issues with interference, especially with oscillators and hard keyers.
Although a better power supply helped a lot with these.
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I have a problem with my video input (Cadet III into Cadet I) that looks similar to @csbolingās issue. Was that problem ever resolved? My patch is:
- DSLR camera through HDMI2AV box into Cadet III RCA Input.
- Cadet III RCA Output to Cadet I RCA Sync Input
- Cadet III Luma Output to Cadet II R/G/B
The camera image is slowly scrolling horizontally, at a rate of not even half an inch per second. Now, the weird thing is that if I patch a ramp from Cadet IV to another output of Cadet II, the ramp does not move. I find this weird, because itās my understanding that the camera is now providing the master sync and if that sync is off, I expect everything to be off! I can also sync my Prismatic Ray to stay perfectly still in this same patch.
In another possibly related issue, my Prismatic Ray canāt seem to be synced through the RCA cable from Cadet I, whereas it works perfectly using the patch cable sync connection.
Does anyone have any suggestions about what could be wrong and what I could try?
first input into the sync generator, then into the video input
so: camera -> Cadet I sync input -> Cadet I sync output -> Cadet III input
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Awesome, that works @reverselandfill!
So my Cadet I RCA sync output is working correctly. And if I now connect the Cadet III Video Output to Prismatic Rayās backside RCA input, it syncs correctly too. So why then does PR not sync this way when I have no camera connected and Cadet I is the master sync?
UPDATE: Strangely, after having synced momentarily, the drifting happened again. I can now report that the Hdmi2AV box is the likely culprit, because I get perfect sync from dvd players into my Cadets.
In my case I am able to sync the Cadet system to a camera (which outputs composite directly, not sure if the HDMI converter box could be a factor) but not to the Vidiot: Cadet I does not seem to be able to lock to sync generated by my Vidiot. If I patch the camera through the Vidiot this also works, Vidiot can lock to the camera sync and this gets passed through to the Cadet system.
As I recall from the schematic this RCA jack doesnāt output the sync generated by Cadet I, it is just a buffered copy of the signal going into the Cadet I RCA input if any. Thatās all the Cadet III is doing too, and for me either configuration (camera ā Cadet I ā Cadet III OR camera ā Cadet III ā Cadet I) works. Edit: okay, I guess I donāt understand why one of these would work but not the other in some cases. A little latency from going through the extra buffer before the genlock circuit?
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Bingo, that explains everything. Thanks for your quick help!
Wellā¦ an update from me. I bought a brand new Cadet 1 Sync Generator (from LZX direct) and built it up - and it has exactly the same issue as my first one, +5VDC on every sync output pin, with a little bit of colour carrier visible as well. I am disappoint 
This time I socketed the ATMEGAā¦ so Iāll get in touch with LZX directly and see if maybe I got unlucky again and got another blank one!
Hello all,
Sadly both of my Cadet 1s are still non-working, and as LZX donāt offer support for their DIY products (I emailed a few times, but given the price of the DIY thatās fair enough) Iām out of options other than to ask the community for help.
Would someone be willing to program an ATMEGA88 with the Cadet 1 firmware and send it to me? Happy to pay for your time, the chip and postageā¦ Iād just like to get a working sync so I can test the cadet 2 and play with all the other cadet modules Iāve already built up! As much as itās fun checking their outputs on a scope, it would be nice to get some actual video output too
Thank you!
If the atmega is the issue (ie not pre-programmed) then lzx will replace this ā¦ as it was a product faultā¦ there was a batch that werenāt programmed at thonk that I know ofā¦ search on here for more details
A few things to try/check:
- Run another verification of the firmware image with your programmer tool. Make sure it fails if you disconnect the tool from the board.
- Read out the fuse bits from the atmega with the tool. depending on byte order in the programming software, these should be CE-DF-F9 or the reverse.
Hey so I think i have the same problem and Iāve noticed that the Cadet 1 is syncing to my LZX Vidiot IF I have a camera plugged into it. Is it possible that the sync-strip abilities are unaffected by the Atmega chip? As a temporary solution maybe try connecting a video source into the RCA sync input of Cadet one and see if that works? As mentioned by Agawell, LZX did chime into this discussion and suggested the possibility of returning the unit to them so they can program the chip and thatās what Iāll probably do once I can take a brake from having fun.
Thanks for your responses guys,
Agawell:
When I bought my second Cadet 1 I asked if a replacement ATMEGA for my first one could be included in my shipment, and they said it would be, but unfortunately it wasnāt. After I built the second Cadet 1 it had the same problems as the first - all the signals look good up until the ATMEGA, but thereās nothing useful coming out. I then emailed support and sales a couple of times about it, and to ask if there was some debugging I could do (e.g. check pin voltages to see if any differed between programmed and non-programmed ATMEGAs) but they havenāt responded. As Lars wrote recently in the 2020 post, they essentially make no margin on DIY and donāt offer support, so I really canāt hold them at fault for that in any way. Itās difficult for me since there are no other DIY video guys who have Cadet gear anywhere near me (possibly not even in the rest of Australia, as far as Iām aware) to compare electronics with and try things out. And postage costs to here are ridiculous.
transistorcat:
I will try these things, thank you.
Vdot:
Iām using an expensive Extron test signal generator (set to colour bars) as my sync source, and Iāve tried numerous other devices: VCRs, vintage 70s sync generator, CFOG Video Equations - all with no luck. I even tried NTSC from the test signal generator, just in case it was an issue with PAL. The LM1881 is doing its job well; I can see good signals on its output pins.
What a sob story eh?
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I can understand that they wouldnāt offer build support, but I would expect the contents of the package to match whatās being advertised. If they promised a programmed ATMEGA and it turns out to be blank, then I think LZX should correct that mistake.
Because I donāt know for certain that the ATMEGA is at fault, Iām hoping someone can program one for me so I can test it out and make sure. Alternatively, if there are any differences between the pin voltages on the pins on a working vs. non-programmed ATMEGA that might give me another way to be more sure. And on the plus side, if I do get a new ATMEGA and it works then I wonāt need to hassle LZX for a replacement one!
I donāt want to make my problem into Larsā problem - he does so much for the video synth community that it would be grossly unfair of me.
To expand on my line of question, the AVR is supposed to generate a sync if no external source is present, and there is very little between the AVR and the output.
If the AVR was correctly programmed and clocked, iād expect you to see the sync signals (with a proper trigger and scope) on the sync bus.
If the fuses are set as the elf file wants them (and knowing nothing of your tool or what software you used, this is not certain), a missing clock would lead to you not being able to access the device with the tool after first programming it.
Unless iām missing something obvious, it doesnāt sound like there are that many ways to break this that will allow you to reach the avr trough the programming interface but still completely fail to get any output out of it
Thanks @transistorcat! Thatās hugely useful. I thought the ATMEGA was there to produce sync signals not natively supported by the LM1881 (for which it seemed to be grossly overqualified!) Knowing that the ATMEGA ought to be self-generating sync signals when the LM1881 has no composite input is useful - since they arenāt on either of my units.
Iām using a cheap usbasp programmer, from a Windows VM running on a Mac since my (work) PC is locked down and I canāt install the necessary drivers. So itās entirely possible I failed when trying to reprogram the ATMEGA (although it claimed success and passed the checksum verification). I used basically the command line provided by brknfixie above:
avrdude -c avrisp2 -p m88 -P com2 -e -U flash:w:LZX-C1-SW-V1.0.elf
I changed the port and programmer type for my unit. The first time I had the programmer header in backwards and it failed, but when I had it plugged in correctly it claimed success
The LM1881 is a sync separator, its function is to extract sync from a composite signal and I donāt believe it can generate sync on its own.
In the Cadet I the extracted sync components are used by the ATMEGA to derive vertical sync and odd/even clock signals. The horizontal sync then is extracted from the composite sync signal using a 74HC4538 multivibrator IC, and has its phase compared to the hsync signal generated by the ATMEGA. The phase difference goes through a passive lowpass filter, then is used to modulate the frequency of a crystal oscillator, which acts at the master clock for the ATMEGA. This creates a feedback system thatās a type of phase-locked loop which ensures that the ATMEGAās horizontal sync tracks exactly the frequency and phase of the incoming sync signal. This way the ATMEGA generates the horizontal sync, vertical sync, etc. at all times. This design is described in more detail in the āCircuit design notesā section of the manual, right after the schematics.
The only output from the Cadet I thatās not generated by the ATMEGA is the RCA output, because this is just a buffered copy of the input signal. This is useful for taking a camera signal and deriving sync from it while passing the unaltered signal off to some other part of your rig for processing.
Sorry to hear this has been giving you so much trouble! As others have said if youāre able to program the ATMEGA at all, and youāre otherwise seeing good signals on the scope, youāre probably almost there. Here is the command line that worked for another builder ā it looks like your command line is missing the fuse settings. Lars posted a screenshot of the required fuse settings in the post right above that. Iāll submit a pull request to the LZX firmware Github with this command line, hopefully that makes it easier to find.
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