Pwm Leds In Pandora


kingoddball

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MWeston said:
The same goes for those extra L2 and R2 pads for someone who wants to consider strapping on a couple extra buttons to the bottom with crazy glue or something. :)


Also, no one has noticed this yet, but there are also pads labeled "KP BL" which can be used to string a bunch of LED's in parallel for a custom light show or something. This output has PWM control and can drive about 8 LEDs depending on the current set for each. These pads would get used up as keypad backlighting if we find it possible to light up the keys without adding a ton of cost to the design. No promises at this time....

I've been reading very old threads and came across this PWM for the LEDS which I have heard of previously (including the L2/R2 additions).
Have any of the Dev's used this feature yet or have any information about this?

How are these programmed? Are they done via the OS? I use PWM a lot for motor control (robots and such) but I have not used it for LEDs.

Also on the pandorawiki user guide (advanced features) it has:
"up to two externally accessible UARTs and/or four PWM signals for hardware hacking, robot control, debugging, etc."

Externally accessible? I have not seen any references to these around.. Are they ports/pins or are they in that EXT port (if so - we have to make custom cables?)

I am far more interested in hardware work and hardware programming then software and if the Pandora can do anything along the line of what I'm thinking then it's an even more versatile device!
 
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Is there an internal micro controller or something that can be flashed?
I see TX & RX which are used to flash Micro controllers (ARM, ATmega etc).

Could be flashed with a Serial to USB using an FTDI cable or USB-BUB....
 
kingoddball said:
Is there an internal micro controller or something that can be flashed?
Tbh, I don't understand the question. You can use the UARTs to flash a controller. I don't see a reason to add a separate controller inside Pandora when the OMAP can do the job already.
 
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Sorry.
I just saw the TX/RX. Those lines are used to flash code onto chips.
I guess I didn't think or word my question very well.

Arduino's and other similar products use TX/RX lines to flash code to memory chips.

I was just wondering what the TX/RX does in the case of the Pandora..
 
whatever you want it too i guess.

make your own circuit against an arduine, and make communication between them, for whatever reason
 
UART just means: Universal Asynchronous Receiver Transmitter
RX is Receive (Cross'ed, meaning RX ends in TX as it receives the signal coming from TX)
TX is Transmit (Cross'ed, meaning TX ends in RX as it transmits the signal to RX)

What you do with UART is up to the user. But its common to either flash using your own protocol or to use RS232 over it


Nothing Pandora or Microcontroller related in here
 
mali said:
This is the pinout of the EXT port plug:
cable_connector_thmb.png
I guess that kingoddball apprise pic with detailed pinout description:
cable_connector.png


kingoddball said:
I am far more interested in hardware work and hardware programming then software and if the Pandora can do anything along the line of what I'm thinking then it's an even more versatile device!

Those UART/GPIO(PWM) pins can be used for any purpouse You want. I'm not sure about if some "driver" is needed or if it just works somehow. UART lines usually need level conversion to RS323 levels for connecting serial devices. Undescribed pin betwen line-in-l and tv-out-2 is (probably) 1.8 to 2.8 V (up to 200 mA) pwr supply.

If You are interested in MCUs and robotics then You can use those UARTs as general serial lines or (and here I haven't clue how yet) directly use them as GPIO (PWM) (ie for driving engines). You need some level conversion and external power supply if You need more then 2.8 V and 200 mA.
 
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peca said:
I guess that kingoddball apprise pic with detailed pinout description:
cable_connector.png

*facepalm*

Sorry, of course :)
 
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To add to what JayFoxRox said, no microcontrollers that I know of are actually flashed over the serial connection. If serial is used, there's usually a bootloader running on the micro and writing the data it receives to its flash memory. Programming the chips directly is done through a different interface. Also important, I think it's been said those 6 i/o pins on the EXT connector are 1.8v.
 
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