Looking for an extremely cheap FPGA board (in quantity, academic use)

hamilton wrote:>
> Digikey part#        ea@100pcs total
>
> 220-1425-ND        3.40    340.00    LCMXO2-256HC-4TG100C
> ED90341CT-ND        0.92     92.00    CONN RECEPT MINI-USB TYPE B SMT
> 497-1236-1-ND        0.287     28.74    IC REG LDO 3.3V .95A D-PAK
> PCB (2.5" x 2.1")    8.50    850.00    PCB I had quoted with PCBcart a
> few weeks ago
> A26509-40-ND        1.402    140.25    CONN HDR BRKWAY .100 40POS VERT
>
>             total    1,450.99
>
> Here is $14.51 per board for most of the components.

Is the $8.50 the price for the PCB only, without reflow soldering of the
components? Would be expensive. Even just 10 boards are much cheaper
here (double sided)

http://imall.iteadstudio.com/open-pcb/pcb-prototyping.html

And how do you program the FPGA? I don't think that you can attach the
USB port to the MachXO2, you need at least a chip to convert the
differential signal to digital, but you can't fit a full USB device
logic inside such a small FPGA, if you want to do some other useful
things with it. I would add a $1 USB microcontroller, but this means
some software development.

For the requested number of >5k devices of course it gets even cheaper,
because usually there is some setup cost of $500-$1000 for reflow
soldering and the parts get cheaper, too.

-- 
Frank Buss, http://www.frank-buss.de
electronics and more: http://www.youtube.com/user/frankbuss

On Sunday, September 9, 2012 12:06:12 PM UTC-5, Gabor wrote:
> On 9/9/2012 12:20 PM, brehob@gmail.com wrote:
> 
> > Hi all,
> 
> > I'm looking for a sub-$20 FPGA board (including everything needed to actually use it).
> 
> > Requirements:
> 
> >     * The device must have reasonable free software that can
> 
> >       handle schematic capture and Verilog (Altera and Xilinx
> 
> >       would be easily sufficient).
> 
> >     * Can manage at least 1K gates and 20 flip-flops.
> 
> >
> 
> > Strongly desired:
> 
> >     * At least one debounced button useable on a GPIO line (not reset
> 
> >       for example)
> 
> >     * At least six switches readable by the FPGA.
> 
> >     * At least six LEDs writable by the FPGA.
> 
> >     * At least four GPIO pins that are reasonably accessible.
> 
> >     * Actually costing closer to $10.
> 
> >     * Can power off of USB without any other supply.
> 
> >     * Can manage at least 5K gates and 50 flip-flops.
> 
> >
> 
> >
> 
> > Would prefer:
> 
> >     * At least twice as much I/O as described above.  More is better.
> 
> >     * Compatible at some level with some larger FPGA line
> 
> >       (Altera DEx line in an ideal world).
> 
> >
> 
> > I'm going to go vendor shopping in a few weeks, but I thought I'd see
> 
> > if anyone knows of anything close to this that's on the market.
> 
> >
> 
> > We'd be looking at around 5K-15K ordered, all for academic purposes.
> 
> > Failing finding a board, we are willing to design and manufacture our
> 
> > own (as a far second choice).  So suggestions on parts would be welcome.
> 
> >
> 
> > Also, any thoughts on using a cheap microcontroller to emulate
> 
> > an FPGA would be of interest.
> 
> >
> 
> > I've found some things that aren't all that close.
> 
> >   * Digilent C-Mod -- $22 in quantity of 1, needs external programmer,
> 
> >     no I/O on-board AFAICT.
> 
> >   * Polmaddie2.  No switches, way too much $$$, but pretty good otherwise.
> 
> >     Way more GPIO/FPGA than we need.
> 
> >
> 
> >
> 
> > Thanks in advance,
> 
> > Mark
> 
> >
> 
> The closest I've seen is a number of Lattice eval boards like the
> 
> MachXO2 "Pico" board for about $29.  I've always suspected that the
> 
> price of these boards is already somewhat artificially low in order
> 
> to win seats for their devices.  It's not clear that you will get
> 
> a better price in volume, but I would think Lattice is a good place
> 
> to start for low cost FPGA's or boards.
> 

Having been struggling with the MachXO2 for the past few months, I'd suggest doing a thorough eval before jumping in with both feet.

While it has a lot of nifty advertised features, not all of them work well, and some (i2c slave) are quite badly broken.  Documentation is mostly okay, but very spread out and not indexed well, with some rough spots.

While this is a fine introduction to the life of a working engineer, it may get in the way of the concepts you're trying to teach :-).  The basic IO, logic and ram functions seem to work as expected, these seem to be mostly copies of previous generations.

Their no cost licenses are valid for one year, so they may also change their policies on 'free' licensing or the included tool set at some future point and leave you with no good way out.

On 9/10/2012 4:09 AM, Frank Buss wrote:
> hamilton wrote:>
>> Digikey part#        ea@100pcs total
>>
>> 220-1425-ND        3.40    340.00    LCMXO2-256HC-4TG100C
>> ED90341CT-ND        0.92     92.00    CONN RECEPT MINI-USB TYPE B SMT
>> 497-1236-1-ND        0.287     28.74    IC REG LDO 3.3V .95A D-PAK
>> PCB (2.5" x 2.1")    8.50    850.00    PCB I had quoted with PCBcart a
>> few weeks ago
>> A26509-40-ND        1.402    140.25    CONN HDR BRKWAY .100 40POS VERT
>>
>>              total    1,450.99
>>
>> Here is $14.51 per board for most of the components.
>
> Is the $8.50 the price for the PCB only, without reflow soldering of the
> components? Would be expensive. Even just 10 boards are much cheaper
> here (double sided)
>
> http://imall.iteadstudio.com/open-pcb/pcb-prototyping.html

The board I had quoted was for a four layer board (RHOS).
My error, the PCB I had quoted was also a 3x3 panel.
So the cost per board would be half what I figured.
( I was using a 2x2 panel in my original calculation)

I did not look up how the LCMXO2 was programmed, so some sort of 
programmer will add a few more dollars.

The 3x cost multiplier was to include reflow of the boards.

Quoting a PCB project can get complicated without a spec to follow.

There is also a bottom line here.

Who is going to put up the capital to have these things built.

Some one like myself would have to put up over $2,000, with no guarantee 
of sales.

With out a spec to follow, the customer may not like what I built and I 
would have to sit on these things.

So I may be out $2k, not a good business model. ;-)

>
> And how do you program the FPGA? I don't think that you can attach the
> USB port to the MachXO2, you need at least a chip to convert the
> differential signal to digital, but you can't fit a full USB device
> logic inside such a small FPGA, if you want to do some other useful
> things with it. I would add a $1 USB microcontroller, but this means
> some software development.
>
> For the requested number of >5k devices of course it gets even cheaper,
> because usually there is some setup cost of $500-$1000 for reflow
> soldering and the parts get cheaper, too.
>

AMDyer@gmail.com wrote:
> Having been struggling with the MachXO2 for the past few months, I'd suggest doing a thorough eval before jumping in with both feet.
> 
> While it has a lot of nifty advertised features, not all of them work well, and some (i2c slave) are quite badly broken.  Documentation is mostly okay, but very spread out and not indexed well, with some rough spots.
> 
> While this is a fine introduction to the life of a working engineer, it may get in the way of the concepts you're trying to teach :-).  The basic IO, logic and ram functions seem to work as expected, these seem to be mostly copies of previous generations.
> 
> Their no cost licenses are valid for one year, so they may also change their policies on 'free' licensing or the included tool set at some future point and leave you with no good way out.

I think the license question is no problem, unless Lattice, Altera and
Xilinx all decide to change it.

-- 
Frank Buss, http://www.frank-buss.de
electronics and more: http://www.youtube.com/user/frankbuss

On 9/10/2012 9:56 AM, AMDyer@gmail.com wrote:
>
> Having been struggling with the MachXO2 for the past few months, I'd suggest doing a thorough eval before jumping in with both feet.
>
> While it has a lot of nifty advertised features, not all of them work well, and some (i2c slave) are quite badly broken.  Documentation is mostly okay, but very spread out and not indexed well, with some rough spots.
>
> While this is a fine introduction to the life of a working engineer, it may get in the way of the concepts you're trying to teach :-).  The basic IO, logic and ram functions seem to work as expected, these seem to be mostly copies of previous generations.
>
> Their no cost licenses are valid for one year, so they may also change their policies on 'free' licensing or the included tool set at some future point and leave you with no good way out.

I've been down this road with Lattice before.  The license "expires" in 
a year but they can renew it indefinitely because there is no additional 
cost to them.  They can also license it to as many computers as you wish 
so don't worry about what happens when you replace that old laptop.  You 
won't get updates after the first year which can be a blessing actually. 
  If it ain't broke...

I haven't tried the new Diamond software yet.

Rick

AMDyer@gmail.com wrote:


> 
> Having been struggling with the MachXO2 for the past few months, I'd
> suggest doing a thorough eval before jumping in with both feet.

Well, since the OP's logic requirements are so low, he might look at
the Xilinx XC95xxXL and XC2R "CoolRunner" CPLDs.  The smallest of these
devices run slightly over US $1, and have over 30 I/O pins.  You'd
need something to handle the USB-JTAG conversion for programming,
there are a number of chips that can do this.  I use the Xilinx
Parallel Cable III, which is just a 74HC125 and about 6 small
components (res, cap, diode) and the schematic is online.  If your
project doesn't actually need USB connectivity, you could build the
circuit of the Parallel Cable III onto the board for under $1 in parts.
It only connects about 5 wires to the PC parallel port.
These CPLD chips have a bit different architecture than an FPGA, but
the Xilinx tools handle all the synthesis and mapping anyway, so it
doesn't matter much.  They are more efficient for wide gates like address
comparators, but have fewer FFs than an FPGA.  Still the 9536 has 36 FF's,
the 9572 would have 72.  I think the coolrunner comes with 64, 128 and
up.

Jon

On 9/10/2012 4:17 PM, Jon Elson wrote:
> AMDyer@gmail.com wrote:
>
>
>>
>> Having been struggling with the MachXO2 for the past few months, I'd
>> suggest doing a thorough eval before jumping in with both feet.
>
> Well, since the OP's logic requirements are so low, he might look at
> the Xilinx XC95xxXL and XC2R "CoolRunner" CPLDs.  The smallest of these
> devices run slightly over US $1, and have over 30 I/O pins.  You'd
> need something to handle the USB-JTAG conversion for programming,
> there are a number of chips that can do this.  I use the Xilinx
> Parallel Cable III, which is just a 74HC125 and about 6 small
> components (res, cap, diode) and the schematic is online.  If your
> project doesn't actually need USB connectivity, you could build the
> circuit of the Parallel Cable III onto the board for under $1 in parts.
> It only connects about 5 wires to the PC parallel port.
> These CPLD chips have a bit different architecture than an FPGA, but
> the Xilinx tools handle all the synthesis and mapping anyway, so it
> doesn't matter much.  They are more efficient for wide gates like address
> comparators, but have fewer FFs than an FPGA.  Still the 9536 has 36 FF's,
> the 9572 would have 72.  I think the coolrunner comes with 64, 128 and
> up.
>
> Jon

If you build the Parllel Cable III into your product, what will you 
connect it to?  I don't think they have built a PC with a parallel port 
in a number of years and my understanding is that the drivers for USB 
parallel ports don't work properly with bit banging software like this. 
  Am I mistaken?  Is this a workable solution?

Rick

rickman wrote:


> 
> If you build the Parllel Cable III into your product, what will you
> connect it to?  I don't think they have built a PC with a parallel port
> in a number of years and my understanding is that the drivers for USB
> parallel ports don't work properly with bit banging software like this.
>   Am I mistaken?  Is this a workable solution?
I have no idea about the USB-parport, but you CAN get computers with real
parallel ports, just not on laptops.  I use the parallel port for lots
of interconnect projects, and the Intel D525 chipset still has parport
support, if the motherboard maker chooses to bring it out.  For this
reason, we use a lot of Intel D525 (Atom) motherboards in projects.

Jon

On Sep 10, 12:48=A0pm, rickman <gnu...@gmail.com> wrote:
> On 9/10/2012 9:56 AM, AMD...@gmail.com wrote:
>
>
>
> > Having been struggling with the MachXO2 for the past few months, I'd su=
ggest doing a thorough eval before jumping in with both feet.
>
> > While it has a lot of nifty advertised features, not all of them work w=
ell, and some (i2c slave) are quite badly broken. =A0Documentation is mostl=
y okay, but very spread out and not indexed well, with some rough spots.
>
> > While this is a fine introduction to the life of a working engineer, it=
 may get in the way of the concepts you're trying to teach :-). =A0The basi=
c IO, logic and ram functions seem to work as expected, these seem to be mo=
stly copies of previous generations.
>
> > Their no cost licenses are valid for one year, so they may also change =
their policies on 'free' licensing or the included tool set at some future =
point and leave you with no good way out.
>
> I've been down this road with Lattice before. =A0The license "expires" in
> a year but they can renew it indefinitely because there is no additional
> cost to them. =A0They can also license it to as many computers as you wis=
h
> so don't worry about what happens when you replace that old laptop. =A0Yo=
u
> won't get updates after the first year which can be a blessing actually.
> =A0 If it ain't broke...
>
> I haven't tried the new Diamond software yet.
>
> Rick

Humm, it's sounding like Lattice is going to be the way to go unless I
can get support from Altera or Xilinx (something I'll pursue if this
gets out of the "idea" stage).

Has anyone worked with Lattice Diamond?  How does it compare to the
software from Xilinx and Altera?  I've been burned by some "bad" FPGA
software in the past (not horrible, just too steep of a learning curve
for the classroom) and would _really_ like the ability to do schematic
capture in addition to Verilog...

Thanks again to everyone for their responses, this has been really
useful!
Mark

On Sep 13, 3:03=A0pm, Jon Elson <jmel...@wustl.edu> wrote:
> rickman wrote:
>
> > If you build the Parllel Cable III into your product, what will you
> > connect it to? =A0I don't think they have built a PC with a parallel po=
rt
> > in a number of years and my understanding is that the drivers for USB
> > parallel ports don't work properly with bit banging software like this.
> > =A0 Am I mistaken? =A0Is this a workable solution?
>
> I have no idea about the USB-parport, but you CAN get computers with real
> parallel ports, just not on laptops. =A0I use the parallel port for lots
> of interconnect projects, and the Intel D525 chipset still has parport
> support, if the motherboard maker chooses to bring it out. =A0For this
> reason, we use a lot of Intel D525 (Atom) motherboards in projects.
>
> Jon

Yeah, sadly for us we have no control at all over what computers
people use, so we can't rely on parallel ports...

Thanks!