Design, Sleep, Check, Repeat

I decided to make a new version of the board that fits on a single square inch to enter this project to the Hackaday square inch contest.

Since the old form factor was mainly influenced by the 7 segment display, I decided to switch to a 0.96” OLED Display that fits the form factor of a square inch board quite nicely.

The board is a complete redesign, however the schematic is mostly the same. I only needed to add 2 10kΩ pull ups to the I2C line of the display.

Square Inch Version

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Low input impedance of ATtinys

According to the datasheet, an ATtiny has an input impedance of 10kΩ or less for a pin configured as input. If this value also is used for the ADC, my voltage divisor has a much too high resistance for an accurate measurement.

We’ll see how this affects measurement as soon as the boards are back from OSHPark.

Hopefully everything can be configured to match my needs.

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