GP2X Ext Port

[NeilS]

Anyone know anything about the specs of the Ext Port? Is it serial? What's the bandwidth? Can you DMA to/from it?

Also, is it true there's an ADC analog-in in there? If so, what's the sample rate of that? How many channels, etc.?

Also, I've seen lots of posts about hooking up USB peripherals. So the USB port's definitely capable of both host and peripheral modes, is it?

Am thinking of getting one, and have lots of ideas in mind but just need a bit of reassurance over how hacker-friendly it really is.

Cheers, Neil

 

[Racemaniac]

afaik the only problem with the usb port is that it's not powered, so if you connect things to it you'll have to find a way to poer them

about the ext port: no idea

 

[Hooka]

Ext port is serial I think (has two UART's I believe...) and the usb is useable in gplinux nobody has written a standalone usb host driver for it or anything.

 

[Vimacs]

no idear whats on there, but on gp32 we have i2c spi 2*uart adc, i also have the complate pinout someware, but i doubt you want it.
for gp2x we just have to wait.

 

[NeilS]

Okay, so have been taking a look at the MagicEyes databook. Seems it has one 12-bit ADC, with a switch to choose between 4 inputs, intended for interface to a touchscreen. As there's no touchscreen, I wonder if this is going to be brought out to the EXT connector?

Can anyone tell from the current photos if the EXT connector at least looks the same as the GP32 one?

It says in the book that min. conversion time is 5 cycles. Can't tell / haven't read enough of it to tell if that's 100MHz system clock cycles or some other clock, but if it is, then analog bandwidth is 10MHz (around half sampling frequency = 100MHz / 5 / 2).

If that's right, then this would be enough to sample a composite video signal directly, so coupled with the hardware support for MPEG4 encoding (as per the MagicEyes data book again), this could be turned into a sort of PVR or a digital video camera, I guess. Obviously you'd still need some way of getting audio in there too, but if there's an SPI bus on the EXT connector there's lots of chips will do the conversion. Maybe an old PC sound card could be hacked up somehow...

Any thoughts? Sound reasonable to anyone else?

 

[Squidge]

The EXT connector on current Gp2X boards is larger than the one on the GP32.

 

[NeilS]

The EXT connector on current Gp2X boards is larger than the one on the GP32.

​

Do you have access to the dev hardware, or did those photos on your blog come from somewhere else? It's just if you have got the dev h/w can you see what's internally hooked up to the ext. connector by following the traces around? Don't suppose there'd be anything useful like a JTAG port on there?

 

[Squidge]

I can't trace the EXT port as it's a multi-layer board connecting some of the pins to the BGA processor. I'd have to remove the processor to find out where they went, which isn't practical.

There is a 14 way connector on the level-shifter board however, so maybe that's meant for jtag.

 

[NeilS]

If the connector is JTAG, the connections made directly to the CPU can be traced via boundary scan. Would need to get a .bsd file for the CPU form MagicEyes though to make it work.

Any idea if any schematics are going to be made available?

 

[NeilS]

If the connector is JTAG, the connections made directly to the CPU can be traced via boundary scan. Would need to get a .bsd file for the CPU form MagicEyes though to make it work.

Any idea if any schematics are going to be made available?

 

[Suschman]

Hi

As seen on some dev photos from the beta hardware (in actual handheld layout) it has definitve serial rs232, and you can quite be sure to have jtag (no one wants to open a unit for in-fab reflash or later debug) and i think at least the video out is also there. What´s the rest can only be hoped...

Greets

 

[Esn]

Sorry, just a practical question: since the ext port is on the right side of the unit where your hand is, what could you actually connect to it without interfering with our playing capability? :huh:

 

[Vimacs]

afaik the ext port was moved to the bottom for the final units.

 

[Squidge]

that is true

 

[Wonder Boy]

If that's right, then this would be enough to sample a composite video signal directly, so coupled with the hardware support for MPEG4 encoding (as per the MagicEyes data book again), this could be turned into a sort of PVR or a digital video camera, I guess. Obviously you'd still need some way of getting audio in there too, but if there's an SPI bus on the EXT connector there's lots of chips will do the conversion. Maybe an old PC sound card could be hacked up somehow...

Any thoughts? Sound reasonable to anyone else?

​

http://www.gp32x.de/board/index.php?act=ST&f=41&t=20690

Un Saludo.