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Old 15th July 2014, 08:27 PM   #11
udok is offline udok  Austria
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I had a lot of work and the project stalled. But now the first PCB is ready and i can start working on the firmware.

The PCB has two layers and it was rather difficult to put everything in the small housing.
The DB25 connector is solderd on the leftmost edge. Its a Norcomp part.

The resistor and capacitors are 0603 SMD with the exception of the 1uF power supply caps. No elkos or tantals are used.
Caps and resistors are quality parts from Murata and Yageo (former Philips).

The left side shows the top side with the line drivers and the EEPROM in the middle. The 24 MHz crystal is rightmost.

On the bottom left are the USB cable pads and the USB ESD protection IC (from NXP).

The right side shows the bottom with the FX2LP USB 2.0 interface IC and the voltage regulator at the bottom (LP2951 with Reset output).

Each data outputs has 2n2 to ground and 22 Ohm in series for damping bus reflexions.

Because of availability and size reasons i stay with the LVC parts for now (74LVCH245APW and 74LVC240APW).

Thanks for your interest,
Udo
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Old 16th July 2014, 05:57 AM   #12
RNMarsh is offline RNMarsh  United States
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Quote:
Originally Posted by udok View Post
I had a lot of work and the project stalled. But now the first PCB is ready and i can start working on the firmware.


Thanks for your interest,
Udo


-RM
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Old 2nd August 2014, 10:32 AM   #13
udok is offline udok  Austria
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Hello,

Yesterday i found time to solder the components on the PCB and to build the hardware together.
At first i thought that the connector may be clumpy but after looking at the result it looks very good.
I attached some pictures.
The best think is: When i connected the cable for the first time to the laptop a windows dialog popped up to install the driver!
This will be the next work to do.

Cheers,
Udo
Attached Images
File Type: jpg Kabel2_Small.jpg (73.2 KB, 225 views)
File Type: jpg InnenFX2_small.jpg (74.2 KB, 220 views)
File Type: jpg InnenTreiber_small.jpg (77.7 KB, 223 views)
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Old 2nd August 2014, 03:44 PM   #14
RNMarsh is offline RNMarsh  United States
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It looks great. A-P might also want to have them instead of their box.


-RM
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Old 3rd August 2014, 02:02 PM   #15
udok is offline udok  Austria
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Their USB box is not too bad:-) But having one simple interface cable is somewhat more elegant...

I have taken a closer look to the AP software. From the driver strings i suspect that AP uses the FX2 USB chip too.

Do you have a preference regarding the length of the USB cable? At first i thought that 3m is good, but after having seen 3m i now think that 2m are ok.
It is still possible to extend the cable with an AP interface cable.

Thx - Udo
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Old 8th August 2014, 12:04 PM   #16
udok is offline udok  Austria
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Hi again,

I want to share new information about Sys2.

Evan has done great work in analysing the AP Sys2 bus interface
I think it is ok to share this information here as AP is not
supporting Sys2 any longer.

In Sys2 the bus is not terminated by 2.2 nF as in Sys1.
Instead Sys2 uses basically 50 ohm source termination.
The Sys2 termination is better with longer bus cables.
The data rate can be higher too.

The logic type has changed to 5 Volt 74ACT245 for the data and
74HCT125 for the status lines.
With the help of discrete resistors the data receivers have some hysteresis added.

The strobe lines EA, EW, ER go to 74HC14 schnitt triggers.
Not 74HCT version - so the use of 3.3 Volt LVC Logic may not be a safe bet in Sys2.

A forum member (Altor?) suggested 74 LV logic, which is a modern well tempered 5 Volt logic.
At first i thought that the 8mA drive capability is too low, but the bus drivers come with 16mA.
74LV logic is indeed a good choice as the AP bus is not high speed.

The AP USB interface uses the same FX2 chip as this design,
but in a larger TQFP package.

I want to support S1 and S2 with one USB interace...
This is possible by combining source termination with 2.2nF slew rate
control.

Up to now a first simple communication with FX2 over USB is running and i am
working on the next steps.

Thx - Udo
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File Type: jpg Sys2_ifm1_1_Evan.jpg (602.7 KB, 141 views)
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Old 9th August 2014, 05:36 AM   #17
RNMarsh is offline RNMarsh  United States
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Quote:
Originally Posted by udok View Post
Their USB box is not too bad:-) But having one simple interface cable is somewhat more elegant...

I have taken a closer look to the AP software. From the driver strings i suspect that AP uses the FX2 USB chip too.

Do you have a preference regarding the length of the USB cable? At first i thought that 3m is good, but after having seen 3m i now think that 2m are ok.
It is still possible to extend the cable with an AP interface cable.

Thx - Udo
I think 2m should be fine if the PC and HW are near each other. -RNM
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Old 17th August 2014, 08:36 PM   #18
KSTR is offline KSTR  Germany
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How could I miss that thread?

USB I/F for Sys1 & Sys2 would be absolutely great. I have a Sys2 (2322) with PCMCIA I/F which is a dying species (I tried to account for that by buying a few older laptops with PCMCIA as long as they're still around, to have spare -- and needed it already, the first laptop's PCMCIA slot went dead recently). USB will continue to be available for a longer time, I hope. I'm volunteering as a beta tester.

Biggest problem, in five years or so, will be finding old computers/laptops with XP, though. ApWin2.24 refuses to run the hardware on anything later than XP.

Isn't implementing the driver the hardest part of it? I have no clue about windows driver coding but would imagine it's hard to 'fake' an existing driver.
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Old 17th August 2014, 11:03 PM   #19
udok is offline udok  Austria
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KSTR: Thanks for your offer to test the thing.
RNMarsh: 2m is now the standard cable length.

Actually i do not fake an existing driver. I use the standard windows USB driver (already preinstalled in Win8).
The AP low level interface functions are in the windows DLL called apio.dll. This low level functions call the driver.
I am rewriting the low level communication functions (about a dozen relative simple functions like ap_write_byte(), ap_reset(), ap_read_triple(), ap_write_triple(),...) and replace the original DLL with my version...

The newer AP2700 software uses the same interface functions (well, almost)....
it may be possible to patch AP2700 so that it will even work with an older S2 or S1.
This assumes that the basic analog commands have not changed..
The newer DSP stuff will probably not work in AP2700.
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Old 18th August 2014, 11:13 AM   #20
KSTR is offline KSTR  Germany
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Do I need Win8 to run it, then?
I'm very reluctant to use any other OS than XP because I always felt that Win7 started to treat a former power user like a complete idiot and Win8 perfected that (feels like using a Mac, that is).
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