@danzup
That is a usefull information (i talk about chinese cheap encoders).
Thank you very much.
Fotis
That is a usefull information (i talk about chinese cheap encoders).
Thank you very much.
Fotis
Dunzup, thanks for the explanation regarding encoders.
Just kidding about speed of the ATmega... I am happy that this work 🙂
One question:
Is it possible to change the state of the PB0-PB3 pins (input relays)? Currently, when not selected they are HIGH.
Can they behave exactly like the pins that control relays in attenuator PC0-PC5 (HIGH when selected)? In this way we are not limited to use relays that operate at 5V, but can also be used 12V relays.
Thanks.
Boban
Just kidding about speed of the ATmega... I am happy that this work 🙂
One question:
Is it possible to change the state of the PB0-PB3 pins (input relays)? Currently, when not selected they are HIGH.
Can they behave exactly like the pins that control relays in attenuator PC0-PC5 (HIGH when selected)? In this way we are not limited to use relays that operate at 5V, but can also be used 12V relays.
Thanks.
Boban
PGA version
Hello everyone,
after a longer period of searching, I decided to build the version posted on thread no. 111, the one with the PGA and encoder. Now, there would be one request if possible: when the system is in standby is the uC also in standby mode? I'm asking because I would like to add a feature that is active on standby, a LED that fades in and out, something like the one shown here Led Fader Circuit - YouTube
Could this be added to the existing project?
Thanks,
Andrei
Hello everyone,
after a longer period of searching, I decided to build the version posted on thread no. 111, the one with the PGA and encoder. Now, there would be one request if possible: when the system is in standby is the uC also in standby mode? I'm asking because I would like to add a feature that is active on standby, a LED that fades in and out, something like the one shown here Led Fader Circuit - YouTube
Could this be added to the existing project?
Thanks,
Andrei
in the production version you can add this feature easily. Check here
Vicol Audio R2R volume controller, Pass B1 Buffer, Salas Shunt regulator - YouTube
Vicol Audio R2R volume controller, Pass B1 Buffer, Salas Shunt regulator - YouTube
Yesterday i attached attenuator after the CD player and att working really nice. But ... There is a "small problem"🙂
From position 0 to position 31 everything is working properly, and does not have any crackling sound. Position 31 is when the first five relay is ON, while the last Rel6 is OFF. Position 32 on LCD is where the problem starts. Active is the last relay, and the first five is inactive. From that point occurring overtones and cracking during further amplification. Strange thing is that at position 32 decreases the intensity of the light on LCD display. After that position intensity of the LCD is normal.
Has anyone had a similar problem and might know the cause of this attenuator behavior? I have checked all solder joint, all grounds...
Thanks.
Boban
From position 0 to position 31 everything is working properly, and does not have any crackling sound. Position 31 is when the first five relay is ON, while the last Rel6 is OFF. Position 32 on LCD is where the problem starts. Active is the last relay, and the first five is inactive. From that point occurring overtones and cracking during further amplification. Strange thing is that at position 32 decreases the intensity of the light on LCD display. After that position intensity of the LCD is normal.
Has anyone had a similar problem and might know the cause of this attenuator behavior? I have checked all solder joint, all grounds...
Thanks.
Boban
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Here is a little movie where you can hear and see the problem described above : Hotfile.com: One click file hosting: Att_2.avi
Be careful, there are camera movements that are more dangerous than in the Matrix 😀😀😀
Cheers!
Be careful, there are camera movements that are more dangerous than in the Matrix 😀😀😀
Cheers!
@jorgovanko
My suggestion is to change places for 5th and 6th relay. If problem occurs at position 16, you can be sure that relay has fault coil. Buy new relay and your problem will be solved.
If nothing changes, replace transistor and/or diode in 6th relay circuit.
My suggestion is to change places for 5th and 6th relay. If problem occurs at position 16, you can be sure that relay has fault coil. Buy new relay and your problem will be solved.
If nothing changes, replace transistor and/or diode in 6th relay circuit.
Hi Misha 🙂
I checked these things several times, everything is working properly. The sixth relay is switched ON only once during 64 position / step 32 / and stays ON until the maximum gain / step 63 on the display /.
I checked these things several times, everything is working properly. The sixth relay is switched ON only once during 64 position / step 32 / and stays ON until the maximum gain / step 63 on the display /.
Now when I saw your Matrix movie, I don't think that anything is wrong. You just threw 2V from CD at amp for computer sound card, which has 200mV output.
There is no source before att on the movie. The same behavior when the inputs are/not short-circuited to the ground.
Crackling or noise related to relay are always sign of DC on input or impedance miss fit .
Please check also the ground loop .
I will check your PCB to see if there are problems .
Also you must connect ground of uC with the audio signal ground by testing the good earth connection.
Also use signal/CD player on one input and test again .
Please check also the ground loop .
I will check your PCB to see if there are problems .
Also you must connect ground of uC with the audio signal ground by testing the good earth connection.
Also use signal/CD player on one input and test again .
Hi Dunzup,
i will send u later PCB layout (PDF files).
Thanks.
Boban
edit: Dunzup, u have PM.
i will send u later PCB layout (PDF files).
Thanks.
Boban
edit: Dunzup, u have PM.
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More eyes see better 🙂
The file is attached... if someone else wants to look the PCBs.
Relays are Omron G5V-2 5VDC : http://www.omron.com/ecb/products/pdf/en-g5v2.pdf
The file is attached... if someone else wants to look the PCBs.
Relays are Omron G5V-2 5VDC : http://www.omron.com/ecb/products/pdf/en-g5v2.pdf
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Hi everybody
I'm about to embark in this project (just waiting for the Atmega16 e some other bits) and I have a few questions.
I'm planing for this one (VC_r2r) I think it was the 3rd one from Danzup and my questions are:
Is it possible to do it with 2 encoders (1 for volume and 1 for input select instead of the 2 buttons)?
I'm planning the use of a 20X2 VFD but I don't know if it is compatible with the HD44780 (can be driven parallel or serial) but I have other LCDs that I can use while I'm building my prototype.
Last question for today is about the attenuator relay...
Can it be made from the atmega16 adc output pins generating a voltage of 0 to 5V from the position of the encoder ?
Only asking because I have a working 256 steps ADC0804 with 8 relays that is controlled by a voltage with a pot and the idea is to control it strait from the ADC pins from the ATmega.
Sorry for all this questions but I can do the hardware and whatever necessary like loading the program to the MPU but I never programed one before.
Any help/suggestion is welcome
Ric
I'm about to embark in this project (just waiting for the Atmega16 e some other bits) and I have a few questions.
I'm planing for this one (VC_r2r) I think it was the 3rd one from Danzup and my questions are:
Is it possible to do it with 2 encoders (1 for volume and 1 for input select instead of the 2 buttons)?
I'm planning the use of a 20X2 VFD but I don't know if it is compatible with the HD44780 (can be driven parallel or serial) but I have other LCDs that I can use while I'm building my prototype.
Last question for today is about the attenuator relay...
Can it be made from the atmega16 adc output pins generating a voltage of 0 to 5V from the position of the encoder ?
Only asking because I have a working 256 steps ADC0804 with 8 relays that is controlled by a voltage with a pot and the idea is to control it strait from the ADC pins from the ATmega.
Sorry for all this questions but I can do the hardware and whatever necessary like loading the program to the MPU but I never programed one before.
Any help/suggestion is welcome
Ric
The relay are the best .
Precaution must be taken about connecting all GND lines from audio and from the digital part to one point, by testing the point of grounding.
I have looked at your PCB and everything seems OK so far .
Now, I have no clue about what is happening there .... sorry .
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Yes it can be done with 2 encoders , in the future I will post such.
VFD display do not offer generic interfaces like the HD44780 (very few VFD implement this) so it is hard for me to offer support for VFD , but if I will find some accessible VFD it is in intention to do , moreover VFD display cannot be find easy this day and are at very high prices !
Also there are PWM port on Atmega which can be setup to provide voltage 0...5V output , but I am very busy now and I cannot do this or in a reasonable window of time .
I think I know where the problem is. First relay i connected/routed with resistors like other 5 relays. First relay is connected with resistors on different way. When Re1 not active, we have voltage divider (R30 with R31). When is Re1 active we have parallel connection between R30 and R31 in series with signal. I will fix it.
Dunzup, is there any calculator for resistors values which is used in R-2R attenuator?
An externally hosted image should be here but it was not working when we last tested it.
Dunzup, is there any calculator for resistors values which is used in R-2R attenuator?
I think I know where the problem is. First relay i connected/routed with resistors like other 5 relays. First relay is connected with resistors on different way. When Re1 not active, we have voltage divider (R30 with R31). When is Re1 active we have parallel connection between R30 and R31 in series with signal. I will fix it.
Dunzup, is there any calculator for resistors values which is used in R-2R attenuator?
Yes , that is the problem and defect !
About the other question :
Resistor-Switch Attenuator Networks for Audio Volume Control
read there all about !
It is like a bible of attenuators in audio and Hi End audio.