Russell Technologies - RT-SPARK DigiSpark not exactly a clone

The RT-Spark: A DigiSpark not-exactly clone

Preliminary

	This is my PCB design for Digistump's excellent Digispark.
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Schematic circuit diagram
	This image is a png file. For PDF version, click here.

	Main differences from Digistump's design: There is no regulator. Vcc connected directly to USB and to terminals. The PCB is uniform width. All the terminals are at the end in a 100mil grid. This end of the PCB can be cut off if not required.
	The LEDs D4 and D5 have blob pads on the back of the PCB (B1 and B2) for easy disconnect if not needed.
Suggested BOM C2 C2012X7R1E475K125AB SMD Multilayer Ceramic Capacitor, 4.7 µF, 25 V, 0805 [2012 Metric], ± 10%, X7R, C Series Manufacturer: TDK Manufacturer Part No: C2012X7R1E475K125AB Farnell Order Code: 2346943 C1 CL21B104KACNNNC SMD Multilayer Ceramic Capacitor, 0.1 µF, 25 V, 0805 [2012 Metric], ± 10%, X7R, CL Series Manufacturer: SAMSUNG ELECTRO-MECHANICS Manufacturer Part No: CL21B104KACNNNC Farnell Order Code: 3013475 D3 BAS316 Small Signal Diode, Single, 100 V, 250 mA, 1.25 V, 4 ns, 4 A Manufacturer: NEXPERIA Manufacturer Part No: BAS316,115 Farnell Order Code: 8734275 D1 D2 MM3Z3V6T1G Zener Single Diode, 3.6 V, 300 mW, SOD-323, 5 %, 2 Pins, 150 °C Manufacturer: ON SEMICONDUCTOR Manufacturer Part No: MM3Z3V6T1G Farnell Order Code: 2463511 D4 KPT-2012EC LED, Low Power, Red, SMD, 0805 [2012 Metric], 2 mA, 2 V, 617 nm Manufacturer: KINGBRIGHT Manufacturer Part No: KPT-2012EC Farnell Order Code: 2449881 D5 KP-2012LSGC LED, Low Power, Green, SMD, 0805 [2012 Metric], 2 mA, 1.9 V, 568 nm Manufacturer: KINGBRIGHT Manufacturer Part No: KP-2012LSGC Farnell Order Code: 2463991 R1 R2 MCWR08X68R0FTL SMD Chip Resistor, 68 ohm, ± 1%, 125 mW, 0805 [2012 Metric], Thick Film, General Purpose Manufacturer: MULTICOMP PRO Manufacturer Part No: MCWR08X68R0FTL Farnell Order Code: 2447707 R3 R4 R5 MC01W080551K5 SMD Chip Resistor, 1.5 kohm, ± 5%, 100 mW, 0805 [2012 Metric], Thick Film, General Purpose Manufacturer: MULTICOMP PRO Manufacturer Part No: MC01W080551K5 Farnell Order Code: 9333924 U1 ATTINY85-20SF 8 Bit MCU, AVR ATtiny Family ATtiny85 Series Microcontrollers, 20 MHz, 8 KB, 512 Byte, 8 Pins, SOIC Manufacturer: MICROCHIP Manufacturer Part No: ATTINY85-20SF Farnell Order Code: 2774978
External links: Digistump home page - digistump.com Digispark wiki page The Micronucleus bootloader Muhammad Talha Khan's Rubber Ducky software This work is licensed under a Creative Commons Attribution-ShareAlike 2.0 Generic License

Comments and interesting info welcome

email link: robert@russelltechnologies.co.uk

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