Difference between revisions of "SeriAlpha"

From Hackstrich
(Initial page for the SeriAlpha.)
 
(Officially cancelling this project as SFE came out with the same thing.)
 
(12 intermediate revisions by the same user not shown)
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== Project Status ==
 
== Project Status ==
Schematic/board done, BOM on file at Digikey, board sent to BatchPCB for prototype manufacturing.
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Revision 1 serial number 1 assembled and test code running successfully.  Revision 2 designed, laid out, and sent to @laen for PCBing.  PCBs and parts for rev 2 received.  Project cancelled as SparkFun came out with basically the same thing.
  
 
== Design Overview/Ideas ==
 
== Design Overview/Ideas ==
* Based around the ATtiny2313
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* Based around the <s>ATtiny2313</s> ATtiny48 in a QFN20 package
 
* Individual transistors for each segment, so it will support all segments on at once and nifty things like PWMing segments
 
* Individual transistors for each segment, so it will support all segments on at once and nifty things like PWMing segments
 
* Built in character generator, so you can just tell the board what letter/number to display.
 
* Built in character generator, so you can just tell the board what letter/number to display.
 
* Targeting the [http://www.sparkfun.com/commerce/product_info.php?products_id=9934 SparkFun-sold 16segment LED displays]
 
* Targeting the [http://www.sparkfun.com/commerce/product_info.php?products_id=9934 SparkFun-sold 16segment LED displays]
  
[[Category:Current Projects]]
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== Revision 1 Design Issues==
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* <s>Unable to disable RESET pin due to silicon errata, so one segment won't work.</s> - Fixed by switching to ATmega48 in revision 2.
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* <s>No bypass caps on PCB</s> - Fixed in revision 2.
 +
* <s>Board could be smaller if MCU moved to bottom of board</s> - Fixed in revision 2.
 +
* <s>Resistor networks and dual-transistors would make assembly much easier</s> - Fixed in revision 2.
 +
 
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== Programming Revision 1 Boards ==
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Revision 1 boards were accidentally missing a programming header.
 +
* Add a green wire from the 3rd pin down on the left I/O connector to the last resistor in the first bank under the MCU
 +
* Add a green wire from the 4th pin down on the left I/O connector to the first resistor pad in the second bank under the MCU
 +
* This enables programming via the left connector (top to bottom):
 +
** 1 - GND
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** 2 - GND
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** 3 - MISO
 +
** 4 - /RESET
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** 5 - MOSI
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** 6 - SCK
 +
** 7 - VCC
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** 8 - VCC
 +
 
 +
[[Category:Cancelled Projects]]

Latest revision as of 13:00, 19 July 2011

SeriAlpha is a small backpack for alphanumeric LEDs (16 segment, specifically). It will accept I2C/SPI communications, and control the LED display attached to it.

Project Status

Revision 1 serial number 1 assembled and test code running successfully. Revision 2 designed, laid out, and sent to @laen for PCBing. PCBs and parts for rev 2 received. Project cancelled as SparkFun came out with basically the same thing.

Design Overview/Ideas

  • Based around the ATtiny2313 ATtiny48 in a QFN20 package
  • Individual transistors for each segment, so it will support all segments on at once and nifty things like PWMing segments
  • Built in character generator, so you can just tell the board what letter/number to display.
  • Targeting the SparkFun-sold 16segment LED displays

Revision 1 Design Issues

  • Unable to disable RESET pin due to silicon errata, so one segment won't work. - Fixed by switching to ATmega48 in revision 2.
  • No bypass caps on PCB - Fixed in revision 2.
  • Board could be smaller if MCU moved to bottom of board - Fixed in revision 2.
  • Resistor networks and dual-transistors would make assembly much easier - Fixed in revision 2.

Programming Revision 1 Boards

Revision 1 boards were accidentally missing a programming header.

  • Add a green wire from the 3rd pin down on the left I/O connector to the last resistor in the first bank under the MCU
  • Add a green wire from the 4th pin down on the left I/O connector to the first resistor pad in the second bank under the MCU
  • This enables programming via the left connector (top to bottom):
    • 1 - GND
    • 2 - GND
    • 3 - MISO
    • 4 - /RESET
    • 5 - MOSI
    • 6 - SCK
    • 7 - VCC
    • 8 - VCC