AT2380v1 // 2 Channels digitally controlled stepped attenuator

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Hello,

If you look the schematics (page 1 of thread) you will see that each relay have two contacts and they
are both used for a single attenuation.
So, the relay would require 4 contacts for symmetric mode, that isn't in the current design.
Regards.

Frex
 
Hello all,

We have now reached more than 20 pre-order for the bare PCB,
so i looked again with the the manufacturer and unit price of the panel goes down to 25€ instead of 30€.
(including the worldwide shipping and Paypal fees).

For reminder the group buy will stop this Saturday, i will send all invoice at same time.
Of course, all orders before this date are welcomed !
(If interested, go to dedicated group-buy thread here)

Frex
 
Hello,

Good news for the PCB group-buy of, all letters has been sent to DIYers.
I also already sent the first release of the design folder to build the project.
(I use your personal email address, if you haven't not receive it, please check spam folder)/

On my side, i continue to work on a new firmware to improve the tracking operation mode and adding some new features.
I also ordered a Bluetooth uart PCB(and one Wi-Fi too) to add an option module on the AT2380.
It would allow to set the attenuator by this way (terminal commands).
For now it's only for fun but it seem that would interest some people.
To follow..

Frex
 
Hello,

Thank's for your feedback.
Bk, i sent you the paste file to your email.
I will add the file for the next design folder i prepare.

I'm finishing some tests with the BlueTooth control of the attenuator.
The new firmware will add some improvements and new features.
It's only a question of few days now.
Regards.

FRex
 
Hello all,

I released today the new v0.23 CPLD firmware for the AT2380 that add :

- Firmware version display at startup
- Calibration mode.
- Relays fast mode operation (for audio volume control applications)
- Bluetooth UART mode attenuator control/measurements
and others code improvement and bugs fix.

Because of these many modifications, i have made a new design folder (v2.1),
The new design folder will be send this day to all PCB buyers on their email.

I also edited the first post of the thread and add download link to some files.
(synoptic, full schematics, complete manual and bill of material).
First post is here.

Frex
 
My build is nearly complete. Anyone else have it up and running?


BK
 

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Hello BK,

Beautiful wiring indeed. Yours SMD oven soldering seem to get better look than my manuals one !
:) . I don't have an oven for now, but i think to get one near future. What do you use yourself ?

Frex



My reflow oven is a small converted toaster oven with the dual ceramic elements operated by a solid-state relay and controlled by an Arduino-based Rocket Scream PID oven controller. The space between the inner and outer oven walls is insulated with fiberglass welding blanket. Very happy with the results! I built mine a few years ago and I notice more options available these days. I get my stencils from OSH and if I'm feeling rich or the pitch is especially fine I opt for stainless steel. Some people can work SMD magic with just a soldering iron, but for me reflow takes the drama out of the whole process. Pick-place requires extra attention. I encourage you to try it and the Rocket Scream site is a good source of info/ideas and I can highly recommend their controller.


BK
 
Hi,

I have mine up, but not running.....

Voltages and current draw check OK as per the build instructions, I can program the MAX V without error, and the first power-on went OK (display of version, then attenuation), but after say 10 seconds the lights went out, and that is it... ?!?!

On power-on, I can hear the relays clicking, but no display, and no LEDs. No reaction to the rotary encoder, nor the disable clock switch.

In my desperation, I tried frequent power-cycling, and for one time the attenuator started as expected, but after a couple of seconds - lights out again.

Any suggestion would be greatly appreciated, since this whole MAX V thing is way over my head, I am a kit builder ;-)

My build is nearly complete. Anyone else have it up and running?


BK
 
Hello hallodeletue ,

No worry, we will try to figure out your issue.

If the board don't power on each time, maybe the first think to do is to check very carefully all soldering joints, in particular the CPLD.You must of course use a magnifying lens !
For any doubt during this check, use a multimeter in Ohms range to verify if it's shorted or not.

Then, i think you can check all voltages at test points during power-on and until you see the display and leds lights out. There is maybe a voltage that become wrong after some time after startup (short circuit).
Note that the Quiet mode switch can switch off all lights (7seg display and 2 leds) so if this pin is not properly connected you can have bad behavior.
To test this, you can try to put your finger on the CPLD pin. If a pin is floating, you may see display blinking.

I hope that will help, i let you to try this and post your results.
Regards

Frex

(What do you use as power supply ? can you post an high res pict of the board ? )
 
I have built up two units and see a very similar problem. They behave as if the Quiet mode is always on (btw, it would have been very useful to label the off position of that switch). One PCB did not get recognized by Quartus, needs to power on/off several times until the Altera is found.

Main symptom is that the 7-segment and dual color LEDs are always off, the encoder does not trigger anything. As if the internal clock of the Altera is dead - or the Altera did not boot at all.

Voltages are present, flashing v0.23 did work. I tried to reflash, this time did not remove L8, and voilà, all LEDs are fully lit during the flash process. So basically a proof that power is there and something could be shown on the display.

I have the parts for Tracking mode on the PCB, but did not enable it (no audio connection and no R44). That shouldn't cause all this, right?

I will do some more checks today trying to find out more.
 
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