A tale of two boards

Lately I’ve been keeping my eye on two recent developments from Xmos and Parallax.

The Xmos staff are developing a Stamp (40-pin DIP package PCB) like board for their XS1-L1-TQFP48.

Mean while Parallax to support their Semiconductor spin off have brought a new Quick Start board of their popular Propeller P8X32A multicore microcontroller.

Cheaper Sparkfun XMOS XS1-L1-64 Development Board

Sparkfun has announced a cheaper version of the XMOS XS1-L1-64 Development Board.

This cheaper revision does away with the FTDI USB based UART section of the board, which never really worked anyway. The IC footprints are still there so you can solder them yourself if you want.

$41.95 (£26.49)

You still need a XMOS XTAG2 Debug Adapter to program it and these cost $50.95 (£32.17).

Maker Faire @ Newcastle 2010

We had a great time at this years Maker Faire in Newcastle over the weekend of 13th and 14th March 2010.

My kids, who are almost teenagers, were dragging their heels as we left our parked car, totally sure they weren’t going to have a good time as we walked towards the Centre of Life.

Walking up the foot bridge to mezzanine level of the maker faire, you could hear the crackling of the musical tesla coil, then as you reached the mezzanine level you were hit by a wall of sound from the various gadgets and things beeping and booping, the musically exhibits being played and of course the Tesla coil. Their faces slowly changed as they realised there was fun stuff here and after a couple of nervous minutes getting their bearings off they went and for the rest of the day it was like trying to herd cats. 😀

I don’t think I saw a single kid, young or old who wasn’t enjoying themselves.

I was finally able to meet up, put a face to a name, with Baggers, Coley, TonyF and Leon from the Parallax and Xmos forums. Leon was being provocative in wearing his Xmos t-shirt whilst on the Parallax Propeller stand with Baggers and Coley. Coley got his own back by having on display a Xmos XC-1 board with a “powered by propeller” label stuck over the Xmos chip. Good nature ribbing 🙂

I had a great chat with John Honniball about his UK101’s he was displaying (I wish I had one for my collection of retro computers 😉 ) and his Arduino music synthesiser.

We met up with Jim and Kat from Sonodrome who were showing off their PSOC (pocket oscillator) and Tubby amps. On Sunday Jim help Sid build his own PSOC. He took it to school for a show and tell and his teacher and class loved it. His teacher was especially impressed that Haydn had soldered it all himself (with a little help).

Abs, not to be left out, spent the afternoon building a mignonette handheld LED game at the Maker table with a little help from me.

Leon has posted some pictures from the faire:

http://www.leonheller.com/Maker%20Faire%202010/

http://www.leonheller.com/MakerFaire%202010%20(2)/

Jim and Kat from sonodrome have also posted some pictures:

http://www.flickr.com/photos/sonodrome/sets/72157623644925608/

and Jonathan Street has a nice write up here:

http://jonathanstreet.com/blog/newcastle-maker-faire-2010

XArduino – A 400-MIPS co-processor for Arduino

Recently I’ve been working on XArduino which is a XMOS XS1 L1 co-processor for the Arduino open-source electronics prototyping platform.

The XArduino board provides Arduino applications with a 400 MIP’s multi-threaded 32-bit co-processor, as well as providing a VGA video output and PS/2 keyboard/mouse input for Arduino application.

It features a standard XTAG-2 to for programming and debugging. In addition the XTAG-2 interface will allow for XK-1 boards to access the VGA and PS/2 interfaces as well as way of connecting standard Arduino shields.

Note: This is a 3.3V-only board

The project is hosted at xcores.com/projects/xarduino

Creative Commons Attribution-ShareAlike 3.0 License

X-DTV – Preliminary schematic and PCB v0.42

X-DTV is a project I’ve been working on with Yvo of xcores.org. The idea is to make a XS1-L1 64 based retro-minimalist homebrew game console similar in concept to the Uzebox and Zuzebox.

Like the X-One before it, X-DTV will use Yvo’s VDP video engine but instead of driving a VGA output it will drive a NTSC TV output. We hope to get PAL TV as well but the 35.46895MHz oscillators have proven difficult to get a hold off (If anyone know where we can get them off the shelve without a large MOQ then drop me a comment).

The X-DTV’s specification is:

• XS1-L1 64 internally clocked to 400MHz with 64K RAM.
• 5-bit R-2R Video DAC for driving NTSC
• 2x NES or SNES D-PAD connectors
• SD Card interface
• Stereo PWM audio
• XTAG-2 Interface
• 2x 5-way XLINK for expansion

The latest (not quite complete) PCB is below:

A PDF of the schematic is here.

xcore.com

The xcore exchange has been launched. Reading the press release its says:

“this new site is to create a community of enthusiastic XMOS users with an entrepreneurial spirit. We want to encourage you to share designs and code as well as develop your ideas.” .

Sounds cool.

X-One – Preliminary schematic v0.10

I’ve talked a few times about the X-One Xmos based console so I thought better put up a schematic to show how it all goes together. A Xmos XC-2 is found at the heart of the console with the rest of the circuit providing a R-2R video DAC, PWM audio and SD Card interface. Ethernet is provided by the XC-2 card its self. The software kernel is Yvo’s VDP video engine.

The pdf is here: XC-2 VGA 0v10

Xmos Development Board comparison

With all the recent Xmos development boards coming out I thought it would be a good idea to compile a comparison list. The full list is here (pdf) but a quick comparison of those boards costing less than $100 is shown below:

Feature	Xmos XC-1	Xmos XK-1	Sparkfun XS1-L1 64
Cost	$99.00	$99.00**	$49.95
Processor	XS1-G4	XS1-L1	XS1-L1
# Pins	512	128	64
# Cores	4	1	1
Max MIPS	1600 MIPS	400 MIPS	400 MIPS
Memory – RAM	4x 64Kx8	64Kx8	64Kx8
SPI Flash	0	512Kx8	128Kx8
User I/O	60 I/O	24 I/O	32 I/O
User Interfaces	USB	none	USB
User LED’s	12	4	2
User Switches	4	2	none
Programming I/F	via USB	JTAG	JTAG
XSYS I/F	none	2	1
Other I/F	Speaker	none	none
Board Size	85 x 54mm	50 x 50mm	84 x 64mm

 

** Includes Xmos XTAG2 USB-JTAG programming adapter (costs $50)

 

Port details for the Sparkfun XS1-L1 64 Development Board

Port details for the Sparkfun XS1-L164 Development Board (pdf is here)

Ports for XS1-L1 64
Pin Name	Pin ID	1-bit	4-bit	8-bit	16-bit	Description
X0D0	16	P1A0				MISO
X0D1	15	P1B0				SS
X0D2	14		P4A0	P8A0	P16A0	JP15 #25
X0D3	12		P4A1	P8A1	P16A1	JP15 #24
X0D4	11		P4B0	P8A2	P16A2	JP15 #23
X0D5	10		P4B1	P8A3	P16A3	JP15 #22
X0D6	7		P4B2	P8A4	P16A4	JP15 #21
X0D7	5		P4B3	P8A5	P16A5	JP15 #20
X0D8	3		P4A2	P8A6	P16A6	JP15 #19
X0D9	2		P4A3	P8A7	P16A7	JP15 #18
X0D10	1	P1C0				SCK
X0D11	64	P1D0				MOSI
X0D12	63	P1E0				JP15 #17
X0D13	62	P1F0				JP15 #16
X0D14	59		P4C0	P8B0	P16A8	JP15 #15
X0D15	58		P4C1	P8B1	P16A9	JP15 #14
X0D16	57		P4D0	P8B2	P16A1	JP15 #13 / TXU1
X0D17	56		P4D1	P8B3	P16A1	JP15 #12 / TXU0
X0D18	55		P4D2	P8B4	P16A1	JP15 #11 / TXD0
X0D19	54		P4D3	P8B5	P16A1	JP15 #10 / TXD1
X0D20	51		P4C2	P8B6	P16A1	JP15 #9
X0D21	50		P4C3	P8B7	P16A1	JP15 #8
X0D22	49	P1G0				JP15 #7
X0D23	48	P1H0				JP15 #6 / TX-O
X0D24	47	P1I0				JP15 #5 / RX-I
X0D25	46	P1J0				JP15 #4
X0D26	45		P4E0			JP15 #3
X0D27	44		P4E1			JP15 #2
X0D32	36		P4E2			JP9 #5
X0D33	35		P4E3			JP9 #6
X0D34	34	P1K0				JP9 #7
X0D35	33	P1L0				JP9 #8
X0D36	42	P1M0				JP9 #1
X0D37	41	P1N0				JP9 #2
X0D38	39	P1O0				JP9 #3
X0D39	38	P1P0				JP9 #4

Sparkfun XS1-L164 Development Board

Sparkfun have a new Xmos based development board. It features the powerful Xmos XS1-L1, multi-threaded processor. The processor is the XS1-L1-64 processor and is housed in a 64LQFP package and has the following features:

• Event driven processing at 400MIPS
• 64 kBytes of SRAM
• 8 threads
• 36 user I/O pins
• 8 kBytes of OTP
• power consumption typically 450µW/MHz

As well as the Xmos processor the SparkFun development board also features a USB interface based on FTDI FT232, external Flash EEPROM and a JTAG header. I/O is provided by 32 I/O pins brought out to pin headers next to a small prototyping area. Checking out its schematic, it looks like it can be powered form both a wall adapter and its USB port. The USB interface is to support a UART over USB and can’t be used to directly program the processor. Instead a 20-pin JTAG interface is provided. This looks to be compatible with Xmos’s own XK-1 JTAG interface and therefore Xmos new XTAG2. I’m hoping my XC-2 JTAG adapter will work with it as well.

Its competitively price at $50 or ~£30 but you still need to provide a JTAG adapter but these are available for $50. The only criticism I would make is I would liked to see the on board USB used to provide a programming (JTAG) interface as Xmos did with their XC-5 board but that said I’m hoping to get one soon and use it in my X-One console with Yvo’s VDP VGA video driver.