Group Buy - Digital Attenuator (Kevin Gilmore)

[iwik]

I assume i have everything connected properly as once it goes i can get the Volume numbers to increase from 0 to 127 and then back down.

I see in the Adafruit example that they have a display init routine that does something like activate the charge pump .

Any way dont worry about it, ill wait till you have it done the way you want, i am in no rush to display anything just yet. Just curious to try

it out. Thanks

Les 

P.S what was the card you were using, i have a Mega here which i am going to try

Edited April 22, 2016 by iwik

[Kerry]

I'm using the Uno.  But it really shouldn't matter.  There could be something slightly different about your display.

We'll figure it out.

 

[Aive]

On 18 April 2016 at 1:57 AM, sorenb said:

Every package has shipped and the sheet updated accordingly.

For those participating in Dig.Att. Boards, Dig.Att.kit and Über amp boards, your have to look at each sheet to check your final remainder.
Those with negative remainder means you have paid too much and will receive a re-fund of that amount.

Please let me know when the package arrives.

Thanks

Currently double checking payments to be sure that the accounting is right, so don't act until tomorrow, thanks.

 

Hey soren, did you manage to ship my package too? Just noticed there's no "shipped" status next to my name in the sheet that's all  Thanks again for organising this GB.

[judo]

I got the parts from soren. I think the resistors and relays can be soldered by soldering iron but the ic-s hardly. Not only the size but the thermal pad seems hard. I made some smt but never with the.solder paste, hot gun method. It was told this is possible with iron, how ? If I have to choose the paste method how can I apply the paste without a mask? Any advice or good tutorial would be appreciated.

[sorenb]

11 hours ago, Aive said:

Hey soren, did you manage to ship my package too? Just noticed there's no "shipped" status next to my name in the sheet that's all  Thanks again for organising this GB.

You got mail. Thanks.

[mypasswordis]

On 4/23/2016 at 3:54 AM, judo said:

I got the parts from soren. I think the resistors and relays can be soldered by soldering iron but the ic-s hardly. Not only the size but the thermal pad seems hard. I made some smt but never with the.solder paste, hot gun method. It was told this is possible with iron, how ? If I have to choose the paste method how can I apply the paste without a mask? Any advice or good tutorial would be appreciated.

I would recommend the heat gun method. If you have to use a soldering iron I would assume you do it like you would any other SMT chip. Solder one pin to hold the chip in place, apply a bit of flux to the other pins then start soldering the rest making sure you don't bridge any pins. If you do, go back and use solder wick when you're done. Be careful not to apply too much pressure or keep the iron in one place too long or you may damage or lift a pad.

I think you mean stencil, as opposed to solder mask. You need solder mask for obvious reasons. You don't need a stencil if you are even a bit careful in applying paste, and the solder mask should take care of the rest when applying heat.

[Kerry]

^this.

I have not used stencils yet and do everything by hand.  Here's a video that gives the basic idea:

Applying solder paste by hand

Don't worry if you get some solder paste between pads of the MAX chip.  Once you heat it everything will be fine.  Chips will center themselves and the paste will flow onto the pads and legs.  Only if you too much paste will it create a bridge.  If this happens just use a braid and iron.

Also, the center pad on the MAX chip is for heat transfer.  It's best if is connected, which rules out an iron.

[DHTGUY]

Soren, All arrived thanks. Have to stay off the coffee to have steady hands for this one 

[judo]

Thanks for the answers. It helps because I thought too the center pad can not be made with an iron and there are videos about everything and the opposit of it so I was not sure. I have soldered similar chips with lots of flux and with solder braid to remove the bridges but I do not like it. Yes, I wanted to say stencil not mask.

[kevin gilmore]

updated volumecontroller.zip

http://gilmore.chem.northwestern.edu/volumecontroller.zip

 

[Kerry]

@iwiki - Les, Try this version. I made sure the full init sequence was run for the I2C version. Somewhere along the line I accidentally removed this code for I2C, but still had it for the SPI interface.

Also, I added code to invert the set / !set for the first four relays based on the layout change for the current group buy boards. You'll need to set line 48 to rev 2.1 instead of 2.0.

This needs to be tested and I have not built the current board just yet.

I'm also going to support the original group buy boards, but need to spend a bit more time with that.

I'd like to add a Bluetooth shield so we can remotely change the volume. We'll need to build an app to support this. I thought to do this with Visual Studio and Xamerin so it will be cross platform for phones.

Edited April 27, 2016 by Kerry

[iwik]

Thanks Kerry,

All working well. Look forward to the planned upgrades.

Les

[DHTGUY]

Is anyone (apart from me) intending to use the 4D Systems dispay and to amend the code from Kerry? 

[kingofsnake]

soren;

  Parts arrived today, many thanks. These boards are insanely small!

[Kerry]

Kevin has reposted a new version of the volume controller at the same link as above.  It now supports v1.0 (original group buy boards as well).  You just need to comment line 104 and uncomment line 105.  Again, these all need to be tested before connecting them to an amp to make sure they are properly controlling the relays. 

If you want to control balanced for version 1.0 boards (two boards), just change the false to true on line 105.

[mypasswordis]

What headers/connectors are people going to use? Some normal shrouded headers?

[kevin gilmore]

these

http://www.mouser.com/ProductDetail/Phoenix-Contact/1725711/?qs=%2fha2pyFadug5do2T4X2cVkQMjmkHXvU%252bnHalaIBCVes%3d

7 and 8 pin for the input/output and 5 pin for the control

or any like thing with .1 inch spacing

 

[mtoc]

On 2016/4/30 at 0:27 AM, Kerry said:

need to comment line 104 and uncomment line 105

What's comment in this sentence?

[sorenb]

1 hour ago, mtoc said:

What's comment in this sentence?

Kerry means taking away line 104 by adding "//" and putting in line 105, by removing "//" so line 104 gets active and line 105 get inactive

 

 

[DHTGUY]

I can't believe I just soldered this - it's unbelievably tiny. Seems to have gone well, though. 

[JoaMat]

Nicely done.

That one is a small one. But else surface mount isn’t that difficult, with some practice…. and it's fun.

[kingofsnake]

Bloody Hell!! That is impressive. With my reading glasses and illuminated magnified lamp this thing is still TINY..

[sorenb]

Back ordered relays arrived today.
Final packages will go out later today.

/S

[iwik]

Kerry,

Just wanted to say that your software is awesome. Had been using the soft that was listed way back when the project first surfaced.

It has some problems, yours is simply pure pleasure. Have it installed up in my T2 and just loving everything. Reckon the OLED display

is real cool and Volume numbers are " purfect".

You asked earlier about noise when using the 12v supply. Can't  hear a single thing and the smoothness of this Att is Fantastic.

Big thanks also to Kevin. 

I just taped off the 12v feeding the front end where it connects to the Board.

Thanks again for all your efforts.

Les

P.S Just in case anyone wonders i'm using a Nano and the V1 board.

Edited June 22, 2016 by iwik

[Kerry]

Thanks for the feedback. I'm looking forward to getting the new board installed in the amp