Difference between revisions of "SeriAlpha"
From Hackstrich
(Documenting rev1 bugs.) |
(Programming info for rev1 parts.) |
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* <s>Board could be smaller if MCU moved to bottom of board</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. | * <s>Resistor networks and dual-transistors would make assembly much easier</s> - Fixed in revision 2. | ||
| + | |||
| + | == Programming Revision 1 Boards == | ||
| + | Revision 1 boards were accidentally missing a programming header. | ||
| + | * MOSI - 5th pin down on I/O headers | ||
| + | * MISO - Tap a wire off the last resistor in the first bank under the MCU | ||
| + | * SCK - 6th pin down on I/O headers | ||
| + | * RESET - Tap a wire off the unstuffed first resistor pad in the second bank under the MCU | ||
[[Category:Current Projects]] | [[Category:Current Projects]] | ||
Revision as of 17:29, 3 October 2010
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.
Contents
Project Status
Schematic/board done, BOM on file at Digikey, board and parts have been ordered and have arrived.
Design Overview/Ideas
- Based around the ATtiny2313 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.
- MOSI - 5th pin down on I/O headers
- MISO - Tap a wire off the last resistor in the first bank under the MCU
- SCK - 6th pin down on I/O headers
- RESET - Tap a wire off the unstuffed first resistor pad in the second bank under the MCU
