I'm trying to build a tiny project. After I program the board, to power the dev board - how can I power it to run the code?


New Circuit enter image description here

Old Circuit enter image description here

Final Circuit

enter image description here

1 Answer 1


The old circuit will not work as you expect. While the ATtiny85 can run happily with 2.7 to 5.5V in this setup it expects 5V. I assume this is due to the high CPU clock setting. To run stable at a high CPU clock it requires 4.5V.

The VIN pin is connected to a linear regulator that has a 2V drop-out. Thus the supplied voltage has to be at least 2V about the target voltage. That is why the shopping page states a 5V (direct) or 7-35V (regulated at VIN) power supply.

Your LiPo charger already has a boost converter built in that boosts the battery voltage (3.0 - 4.2V) to 5V. No need to use a separate DC-DC boost converter here.

Just connect OUT+ to 5V and you are done.

  • Thanks, so the final circuit would be correct? It would have enough power to light up standard 3mm leds connectected to the pins?
    – 3kstc
    Feb 8, 2019 at 2:24
  • Yes, this is the wiring one would expect.
    – Kwasmich
    Feb 8, 2019 at 7:18
  • @Kwasmisch I have one more question. Would you kindly be able to help me out please?
    – 3kstc
    Feb 12, 2019 at 3:15

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