Build your own USB tuner- will work with Minitioune

[G4EWJ]

The datasheet indicates that all 4 VIO pins should be connected to V3V3.

Connect V3V3 to VIO (CN2, pins 1, 3 & 5 to CN2, pins 11 & 21 and CN3, pins 12 & 22).
This connection provides the correct 3.3VDC operating voltage for VCCIO on the FT2232H chip.

Which regulators did you use?

Brian

[g8gtz]

I worked to latest diagram that I posted - http://www.batc.org.uk/forum/download/file.php?id=361

It does have CN 2 pins 1,3,5 and 11 connected together but not 21 or CN3 12 and 22 connected but seems to work OK. There are no external 3.3v connections to the FT2232 so presume it uses the internal regulator.

Now running on an old 32 bit XP and new 64 bit Win 8.1 laptop.

Noel

[g8gtz]

Jean Pierre sent me these notes:

The best setup for a very low signal at SR250 is to set the pll corrector to value 2.

When we work low SR, the Nyquist Filter is not always at the best as it must be, so the signal shape is not as narrow as it should be or not exactly symmetric... so when the derotator must find the exact centered frequency, for very low signal, we use this corrector to help it.

At SR250:

For my Dektec DTA107,PLL corrector is 0
For UgglyDATV PLL corrector is 3
For DTX1 PLL corrector is 2

This is useful when we want to get a signal very low in the noise, and lock will done quickly.

[M0DTS]

Very useful Noel, thanks.

Brian:
I used the same 3.3v regulator as i used on digithin TC1262-3.3v.
The 1.8v reg i use with diode to get to 1v is an AMS1117 1.8.


No luck getting MiniTioune to work on a laptop yet, only working on my i7 desktop machine with win7 64bit.
Laptop1: OLD! Compaq 1GHz running XP - gives a floating point error when MiniTioune starts up..?
Laptop2: HP 2.2G dual core running Vista32bit - MiniTioune Starts up OK but runs very slowly, gives an error relating to resetting portb every few seconds so i'm unable to configure the settings...

Both laptops have most recent drivers installed and active (2.12)

Any ideas?

Rob

[G4EWJ]

Thanks Rob.

I've been looking at some small regulator boards (see elsewhere) but I've had some problems. I think I'll do the same as you and drop down to 5v with the LM2596 board and go from there.

Brian

[M0DTS]

I think you could get away with a 8v then a 5v regulator in series to spread the heat dissipation rather than the switching reg.
I've not tried with just a regular TO220 5v reg on a heat sink yet, it will work as long as the heat sinking is enough.

Rob

[G4GUO]

http://www.linear.com/product/LT3022

Bit pricey though.

These are much cheaper http://www.ti.com/product/lp3879/description

- Charles G4GUO

[F6DZP]

Hello,

About 1V, I don't think that the solution to produce 1,7v and use a diode to go down to 1V is a good idea, there are high variation in the number of mAmp asked

The 1v power supply must be very well filtered.

For errors Rob encounter I think 2 possibilities:
- noise on power supply ( 2 OM had some problem like that solved it by improving the filtering)
- noise on I2C buss. If you look at Sharp documentation you will see 2 capacitors of 30pF on the 2 I2C lines

I think I will develop ASAP
- a tool that will show how your I2C line perform
- a button to stop the thread "constellations display" that ask much CPU% on old PC.
I have written some details about different PC I have tested.
Even on the lowest powerful PC ( pentium4 1.9 MHz) I have absolutely no error when Minitioune is running.

Jean-Pierre F6DZP

[G0NMY]

Very useful Noel, thanks.

Brian:
I used the same 3.3v regulator as i used on digithin TC1262-3.3v.
The 1.8v reg i use with diode to get to 1v is an AMS1117 1.8.


No luck getting MiniTioune to work on a laptop yet, only working on my i7 desktop machine with win7 64bit.
Laptop1: OLD! Compaq 1GHz running XP - gives a floating point error when MiniTioune starts up..?
Laptop2: HP 2.2G dual core running Vista32bit - MiniTioune Starts up OK but runs very slowly, gives an error relating to resetting portb every few seconds so i'm unable to configure the settings...

Both laptops have most recent drivers installed and active (2.12)

Any ideas?

Rob

Rob incase you have not done so make sure you disable Power-saving on the laptops as this then stops windows monitoring the ports etc incase they need turning off!
Cheers Mark
GØNMY

[g8gtz]

Rob,

I had a divide by zero / floating point error on the Win 8.1 64 bit machine. Jean Pierre suggested noisy power rails and I decoupled the 5v and 1v rail with a ceramic 10uf (as per Digithin board) and it cured it....

Re 1v reg - I am using an LP3879 running off the 5v line and it does still get hot even with a small heat sink on it - considering running it off the 3.3v rail...

73

Noel