Commit 5aa70c4e authored by Jan Kasprzak's avatar Jan Kasprzak
Browse files

Project: step-up converter 

I have decided to add various projects using Tinyboard directly
to this repository. The first project is a step-up converter
with current feedback for a string of LEDs.

The firmware is a dumbed-down version of firmware for my other
project: http://www.fi.muni.cz/~kas/bike-lights/, modified
for ATtiny45.
parent d2fca2fd

projects/step-up/README

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Step-up converter with current feedback measurement.



CPU: ATtiny45

Driven by PWM output OC1B (PB4 pin) with MOSFET.

Current feedback measured at ADC3 (PB3 pin).

Output on the PB4 header (pin 1 is negative, pin 2 is positive side).





Bill of materials:



C1,C2	1.5uF tantalum

C3,C51	10uF ceramic

D50	SS24 Schottky diode (SMB package, 40V, 2A)

L50	470uH, 390mA, 200 mil pin distance (probably too big for 20mA LEDs :-)

PB4	two-pin header soldered to pins 1 and 2 of PB4

Q50	IRLML6344TRPBF N-channel MOSFET, 30V, 5A, SOT-23 package

R40	220nF capacitor (not resistor!)

R45	1K5

R50	15K

R51,R53	0R00 (zero-ohm link)

R55	1R0 (can safely measure currents from ~8 mA up, for smaller currents use higher value)

U1	ATtiny45-20SU

U2	MCP1703T-5V





Firmware:



The firmware is a dumbed-down version of firmware for my other

project: http://www.fi.muni.cz/~kas/bike-lights/, modified

for ATtiny45.