Solder Pads. How Many And What Can They Do?

[thoughtcriminal]

Sorry if my questions seem a little noobish, I'm just beginning looking at hardware hacking. What I'm wondering is what kinds of things can be added to the hardware using the solder pads? I'd love to drop in a gps chip and a larger internal flash memory to hold my day to day stuff. I'd imagine this could be done yes? I know I'm not going to put another processor into it using them or anything, but how about more RAM? And theoretically, how much extra stuff can I cram onto the board?
thanks
TC

 

[cbox]

As far as from what I've read around here, the RAM is hard wired into the system and cannot be upgraded.

And from what craigix has said, the inside of the case is pretty snug so not a lot of room inside.

 

[Chip]

See for yourself. Everything is well labeled.

The RAM is part of the OMAP3530 SoC. It cannot be replaced.

 

[Squidge]

The RAM is part of the OMAP3530 SoC. It cannot be replaced.

Well, not really a part of it, but the POP design makes it damn difficult to replace

Also, last time I checked, the internal flash is the same POP format, and so has the same limitations.

Why would you want a larger internal flash memory anyway? That's what SD cards are for

 

[Geuben]

Just out of curiosity, what are KP and BL (on the right in the middle)?

 

[atomicthumbs]

I'd guess that KP is keypad and BL is backlight.

Or Kitchen Patrol and Bi Lovin'. I dunno.

 

[Geuben]

I'd guess that KP is keypad and BL is backlight.

Or Kitchen Patrol and Bi Lovin'. I dunno.

I did think keypad, but all the buttons etc are on the other side of the pcb...perhaps its for a peanut dispenser. I think the backlight is in the LCD as bought from the manufacturer.

 

[gruso]

I think it's one phrase - Keypad Backlight. There was a fair bit of talk on doing mods like this, looks like MWeston came to the party.

 

[verm71]

See for yourself. Everything is well labeled.
RS-232? Hmm... I don't recall seeing which component would be using that... From the renders at http://www.gp32x.de/board/index.php?showtopic=43741 there doesn't appear any port on that side of the case, where the 3 solder pads are. I'm only guessing here.

 

[gruso]

You're right, there's no RS232 port. But it's easily accessible on the PCB for those who want it (devs & modders, basically). That's the beauty of Pandora.

 

[nubie]

look over MWeston's posts, he designed the board.

Go to his profile, choose profile options -> view all posts from this user.

 

[verm71]

look over MWeston's posts, he designed the board.

Thanks, I looked it up and found that it's there for design-time debugging.
Original answer from MWeston

 

[enigmacipher]

okay, so i am kind of a noob, but I would like the answer to orginal poster's question as well.

It looks like we have:
R2
L2
Battery
External Mic
TV out

Unknown to me:
RS-232
KPBL

I looked up RS232, and it looks like what I would call a 'serial' port, is that true?
I guess KPBL means Keypad Backlight? any confirmation?

Are there any solder pads I missed? Any more on other side?

 

[Geuben]

I knew it would turn out to be a mistake to say KPBL was keypad backlight. PLEASE PLEASE PLEASE don't take Gruso's word on it being a keypad backlight! It was merely speculation!

I really don't want to see a rush of "wheres the keyboard backlight!?" threads, theres already enough crap being sprouted everyday on here.

 

[MWeston]

There have been many changes since previous discussions.

KP BL = Keypad backlight (I just put it on the bottom to be clear of the membranes on top and it has no use for us right now, just another hacker's tool not recommended for average users. Placing a couple of pads on a PCB and actually designing buttons that can pass light through are two completely different things so please don't criticize why I would put them on there to tempt fate)

EXP CONN is now gone, sorry! Most of it got used up by the Bluetooth module and I also added a couple extra features that needed GPIOs.

L2/R2 spare are still there. This is for hackers that want to modify the case internally (voiding the warranty of course).

The AV connector has the bulk of the expansion:

- UART3 (RX,TX) connected to the console in Linux, this one has hardware support for CIR so could rebuild kernel to switch console to UART2 if necessary
- UART2 (RX,TX,RTS,CTS), can also be four GPIOs, software I2C, software SPI, or even extra button GPIOs without taking the case apart
- S-Video or composite outputs
- Line input
- Line output
- Power (up to 200mA at 1.8V - 2.8V)

RS-232 would only be available through an external converter, but the 2.8V supply is there to make it self powered.

 

[gruso]

You wouldn't believe it. I just went searching for the answer, and found ^^ that very post in the search results without realising it had just been posted here. Confusion and hilarity ensued.

 

[Geuben]

You wouldn't believe it. I just went searching for the answer, and found ^^ that very post in the search results without realising it had just been posted here. Confusion and hilarity ensued.

Some good speculation from you there with Keypad Backlight. A backlit keyboard would be nice, but as MWeston said, the logistics of the LED placement and the membrane will probably mean that there wont be too many people modding one.

 

[WizardStan]

KP BL = Keypad backlight (I just put it on the bottom to be clear of the membranes on top and it has no use for us right now, just another hacker's tool not recommended for average users.

Out of curiosity, is it just a pair of powered pads (that Peter Piper picked) or is there something special about them that made you think "backlight!" when you designed them in? Software on/off or current limited or something? I'm thinking, even if the original conception was as a backlight, perhaps it can be put to more generic uses.

 

[MWeston]

One pad connects to the battery and the other to a ball on the power management chip that provides a current sink for up to 160mA. It has PWM control for brightness variability so it was designed for specifically driving LEDs. It's not best designed for an LCD backlight because each LED requires its own current limiting resistor and all are connected in parallel so guaranteeing brightness uniformity is not as good as a dedicated chip.

 

[enigmacipher]

I wanted rumble...

Incredibly easy mod, plus cheap and useful. But it looks like the keypad backlight can't be used for a rumble?