#101249 - jake2431 - Mon Sep 04, 2006 12:50 am
Okay, say I wanted to take my ARM7 out of a gba that no longer works so that I can connect it to a bread board along with some RAM, EEPROM, Serial port, etc. How would I go about learning to do this. I want to be able to take apart a broken gba takeout the ARM7 etc., put it on a board, and interface it to my computer so that I can run assembly to it and explore the processor further. I want to know the steps to take to figure out how to do this.
P.S. I am not going to rush in and just start doing this. I just want to know what all I need to learn to be able to make a ARM7 'motherboard'(I guess you could call it that) that I could interface with my computer and make it do physical things like light up a light-bulb etc.
#101258 - tepples - Mon Sep 04, 2006 1:55 am
The ARM7 in the GBA is not just a plain CPU. It has a lot of I/O on the same die, including the entire 2D video hardware.
_________________
-- Where is he?
-- Who?
-- You know, the human.
-- I think he moved to Tilwick.
#101273 - jake2431 - Mon Sep 04, 2006 3:09 am
Are you saying you can't use it for anything else? Because it sounds like it would be more suited for it with builtin I/O pins. Like a BS2 microcontroller has 16 I/O ports. It sounds like the ARM7 is kind of a hybrid between a microprocessor and a microcontroller since it has the I/O pins.
#101277 - tepples - Mon Sep 04, 2006 3:30 am
You'd have to provide your own EWRAM, ROM, and LCD, and it would still try to read the ROM header and display the GBA logo animation.
_________________
-- Where is he?
-- Who?
-- You know, the human.
-- I think he moved to Tilwick.
#101278 - jake2431 - Mon Sep 04, 2006 3:48 am
Oh okay, got ya. That's what I wanted to learn how to do was add that stuff, but the fact that it would still try to read the ROM header and display the GBA logo animation scares me but I guess if I gave it that information I wouldn't actually have to use it. I just thought at one time I had seen where someone used a gameboy as the "brain" of their robot and I am in a robotics class at school right now using a robot with a Basic Stamp 2 installed. The code is ofcourse in basic and doesn't have anvanced capabilities. I don't believe it can multi-task, I just started and I am already running into limitations with it. I wired a circuit for a piezospeaker and figured out how to send it the right frequencies to play music and have already programmed it to play the battle victory music from final fantasy and the zelda overworld theme, but since as far as I know right now(and I may find out different later) it doesn't multitask I can't get it to say maybe dance while the music is playing etc. Because you have to send it commands like PAUSE 200 to control the motors and when you do this it pauses the music also which is no good. I plan on pushing this current platform as far as I can, but am toying with future ideas for controlling a robot and since I like the gba I thought it would be really cool if I could do that and I would learn a lot from building the board. I'm also looking at pic microcontrollers which look really promising if I can't figure this out. But for now playing with this circuitry and the BS2 is extremely fun. I just eventually want a platform that is not so limited once I am ready for an upgrade.
#101538 - sgeos - Wed Sep 06, 2006 10:23 am
There was some sort of GBA robot controller that some company made.
It looked cool, but my memory fails me now. Use google or hope somebody else remembers the specifics.
-Brendan
#101579 - jake2431 - Wed Sep 06, 2006 6:19 pm
Found it. Thanks!
#101582 - josath - Wed Sep 06, 2006 6:59 pm
If you really want to do some custom ARM7 type stuff, you'd probably be better off buying a premade dev kit than trying to roll your own. For example, check this one out:
http://www.sparkfun.com/commerce/product_info.php?products_id=475
It's designed for development, unlike the gba which is designed as a videogame handheld, so it has a lot of nice extra features which may be more difficult to add on to the gba.
| Quote: |
Price: $59.99
* MCU: AT91SAM7S64 16/32 bit ARM7TDMI? with 64K Bytes Program Flash, 16K Bytes RAM, USB 2.0, RTT, 10 bit ADC 384 ksps, 2x UARTs, TWI (I2C), SPI, 3x 32bit TIMERS, 4x PWM, SSC, WDT, PDC (DMA) for all peripherals, up to 60MHz operation
* Standard JTAG connector with ARM 2x10 pin layout for programming/debugging with ARM-JTAG
* USB connector
* Two channel RS232 interface and drivers
* SD/MMC card connector
* Two buttons
* Trimpot connected to ADC
* Thermistor connected to ADC
* two status LEDs
* On board voltage regulator 3.3V with up to 800mA current
* Single power supply: 6V AC or DC required
* Power supply LED
* Power supply filtering capacitor
* Reset circuit
* Reset button
* 12 MHz crystal on socket
* Extension headers for all uC ports
* PCB: FR-4, 1.5 mm (0.062"), soldermask, silkscreen component print
|
#101618 - jake2431 - Wed Sep 06, 2006 9:45 pm
Yeah, thanks. That looks really good. I will definetly check it out. The only reason I wanted to use the ARM out of the gba is that I ordered 3 gbas that don't work and the seller doesn't know why. They were cheap and I was thinking, hum maybe I can do some cool projects with these since I am getting into electronics more. And then pray that the processor isn't fried. But thanks very much I will probably buy a board when I get a chance. If anyone sees any cheaper(even though these aren't bad) let me know.
#101661 - jake2431 - Thu Sep 07, 2006 3:41 am
Before I get a new development board I think that this would be a nice upgrade from the BS2: http://www.sparkfun.com/commerce/product_info.php?products_id=756