NEW !!! Full differential PI front end.

[WM6]

What about a high efficiency, high sensitivity detector, with only essentials, to keep cost down?

Hi Tinkerer

From my perspective, that's goals are exactly what you wrote here.

I think this applies to anyone who uses detector to find something and not to the bells and whistles parade.

Best wishes

[WM6]

Shortly I will post a block diagram of the system as I know some of you are having trouble following what we are talking about.

moodz

Very nice aim, moodz. Thanks in advance.

[hobbes_lives]

Hey Moodz,

Is that the $49 Xilinx starter kit from AVNET? I've almost purchased one several times now, but haven't done so as of yet. I keep wondering how much time I'll have to work with it, given all of my other projects that are in the works right now. (None of these current projects are MD related, unfortunately.)

[Krzysztof]

Hey Hobbes Lives.
I think. it it that was one should was several months; this oneself it tells easily but new family, technology plus instruments. It was one should work in addition details - this lasts.
I wish pleasant adventure it - goes new!
I begin just recognizing technology PSoc Cypress, so as FPGA but from additional analog blocks and memory FLASCH as well as core M8 or Cortex to choice: 8, 16, 32 bit. All in one ankle - until it turns me with curiosity, I got already today set and programmer unit.
I want to alter from Atmel my MAG on new family PSoC, I start just!
Best regards Chris.

[moodz]

Hey Moodz,

Is that the $49 Xilinx starter kit from AVNET? I've almost purchased one several times now, but haven't done so as of yet. I keep wondering how much time I'll have to work with it, given all of my other projects that are in the works right now. (None of these current projects are MD related, unfortunately.)

It sure is ... since I had to pay $US 70 in postage I bought six of them.

[ve7it]

Hi Paul (moodz),
What ever happened to the work you were doing on the zpi 1.0 with the dspic controller?
Did you ever publish the dspic code? From the forums, it looks like you got lured away by the fpga project. I would like to have a go at the ZPI design as I am not up to speed on fpgas, but have worked quite a bit with the dspic. The zpi design was a nice combination of hardware and software. The complexity is appropriate for the home brewer to make PCB's and software modifications. Would you consider sharing the dspic code?
cheers from Canada

[moodz]

Here they are ...

Hi Paul (moodz),
What ever happened to the work you were doing on the zpi 1.0 with the dspic controller?
Did you ever publish the dspic code? From the forums, it looks like you got lured away by the fpga project. I would like to have a go at the ZPI design as I am not up to speed on fpgas, but have worked quite a bit with the dspic. The zpi design was a nice combination of hardware and software. The complexity is appropriate for the home brewer to make PCB's and software modifications. Would you consider sharing the dspic code?
cheers from Canada

Note this code is by no means complete ... it was mainly built to test the differential front end.
Here are the last few builds... the last couple of builds up to 18 are missing for some reason however most of the guts is there. There are main modules to do the fast ADC, RS232 comms to dump waveform, integration and even FFT. What is missing is LCD driver, menu,rotary knob controls and ground balance subtraction. Hopefully you can read the code and figure something out. Note that the TX pulse is really rudimentary ... I was going to setup a PWM output ... never got round to it. The ADC starts sampling the waveform straight after the Tx pulse as I remember it. Stuff comes out the RS232 ports to monitor what is going on.

Have fun. Moodz.

Metal10.zipMetal11.zipMetal13.zipMetal14.zip

[moodz]

FPGA progress

..more coding progress.
Vertical channels adjustments now available to CPU.
Added LCD driver HDL.
Added Rotary knob driver HDL.
The LCD display is accessed via the VGA RAM. By writing to specific 32 characters addresses in video ram the LCD is written also. This is helpful for menu displays when the VGA is not connected to the FPGA board.

The development board is a Spartan 3E500 from digilentinc.com

here are the 4 channels displayed 600 x 800 from the VGA port on the FPGA board showing raw input from the on board ADCs



below .. the board showing the LCD ... note the text in the lower right hand corner of the VGA in the pic two up. The LCD displays on the VGA as well.



below is the serial console attached to RS322 port 1 on the Spartan board. 115.2 Kb
If you want to read / write stuff from memory the addressing is 32 bits The video ram starts at 0x50000000 Line 1 of the LCD is at 0x50001040. You can read and write memory from the console menu. The rotary knob is available on the IP port GPIO bits 0 to 7. The 8 LEDs on the board will also change according to the Knob being turned.



If you want see the moodz detector platform for real I have supplied the bitfield file ... you will need the Xilinx Impact tool to load it into the board ( you will have to supply the board ).
dspexplorer.bit.zip

TODO ... put the DSP filters back in and the pulse generator. What I am working towards is a general purpose but high performance platform for testing different MD technologies. With the right ADCs and DACs this puppy will also do VLF / IB as well as PI. All the controls for the TX, Rx, displays, filters, knobs, switches, DACs and ADCs will be available as GPIO or memory mapped to the CPU. The CPU really only has to do some housekeeping ( user menus and mode switching etc ). The CPU is MIPs compatible and has an update GCC toolchain which can generate highly optimised code.

MooDz

[moodz]

FPGA progress

Completed porting the detector code from the big expensive Spartan 3E board to the much smaller cheaper ( $US 49 ) Spartan 3e board.

The design fits very nicely into the chip and the four channel scope and VGA display function is still included.
LCD 2 x 16 char driver OK.
Rotary encoder control for volume etc OK
Pulse Generator for PI Tx OK
DSP processing chain OK
2 x 24 bit ADC input OK
Serial Port at 115.2 Kbit OK
32 Bit CPU @ 50 MHz OK


I have ordered the Mosfet driver chips to interface to the 3.3 volt cmos ports on the fpga and the 2 x 16 LCD displays and Rotary switches.

Below you can see that the board is quite compact. There is 24 bit ADC chip plugged into one of the IO ports for testing. There is a 40 pin header to connect to the front end board. The frontend board will carry the Mosfet, protection diodes, Amp ( if required ), ADC, damping resistor etc ... not much really.

The total cost of all the electronics and case will be cheaper than $US 100
Add your poles and coils of choice.



Success ! the MooDz detector runtime starts up on the small board.



cheerz from moodz.

[nick_f]

Completed porting the detector code from the big expensive Spartan 3E board to the much smaller cheaper ( $US 49 ) Spartan 3e board.
cheerz from moodz.

Hi Paul,
I am very impressed with what you achieved with these Spartan boards. I checked on the internet where these boards can be purchased from and I could not find them, either on xilinx web site or from avnet. Could you please post a link where you bought them from?

Regards,
Nicolae

[hobbes_lives]

Nicolae,

Google "avnet spartan 3a evaluation kit". It looks like avnet is out of stock right now.

[moodz]

Hi Paul,
I am very impressed with what you achieved with these Spartan boards. I checked on the internet where these boards can be purchased from and I could not find them, either on xilinx web site or from avnet. Could you please post a link where you bought them from?

Regards,
Nicolae

Thanks Nick

avnet part no is .. AES-SP3A-EVAL400-G

moodz

[moodz]

Alternative to commercial FPGA board.

If you cant get a board consider making your own board

ALL the functionality I have made is INSIDE the fpga. The VGA interface is a few resistors. The rest is just digital I/O pins.

The other bits on the commercial board are mainly there to demonstrate interfacing FPGAs to different peripheral devices like temp sensors and flash mems etc.



XC3S400A-5FTG256C

digikey part no is 122-1580-ND

price for chip is $US 19 each.
you would also need an Xtal oscillator pack and a serial prom and 3.3 volt regulator.
( bout another $5 )

It is a BGA chip however these are easier than you think to solder.
( I can provide detail on the process I use but have not time to write instruction / photo at moment. )

moodz.

[nick_f]

Nicolae,

Google "avnet spartan 3a evaluation kit". It looks like avnet is out of stock right now.

Hi All,
Thanks for help. Now I understand why I could not find it. It was refered to as "Spartan 3e" instead of "Spartan 3a". I thought the difference is in lowercase e, compared to Spartan 3E...

Best regards,
Nicolae

[moodz]

This board is ideal for this type of FPGA development.

http://www.sparkfun.com/commerce/pro...oducts_id=8458

Check out the schematic ...very simple.

A bit pricey at $99 but OK. The MooDz detector code will easily fit into this.