Natalia
Avnet distributes electronic components and we wanted to create a cool badge. This board is a prototype we made with Inkscape, KiCAD and the svg2mod script.
We would like this board to be part of the soldering challenge during the Jalisco Maker Faire on November 2019.
All ATTINY85 GPIOs are used to lite 5 LEDs and use a push button to change modes. We used ATMEL Studio 7 to change fuses so reset pin could be used as GPIO too, but we missed the current limitation of this pin (around 2mA?). Let's say tests were done using a Digispark board powered with 5V USB so this was enough voltage to power all LEDs but when 3V battery was used reset pin was too dimmed because of the current source pin capability.
The part available at the time laying around was a NTR2101P P-channel MOSFET with low Vth and enough current to lite the LED used in reset pin. So we used this to fix our mess.
This is the updated schematic with the transistor.
We are unsure if swapping reset pin and the button pin will work because we are using interrupt on pin 2, and to do so we have to restore the fuses, but before that, the high voltage serial programmer is required. And for development purpose.. is time consuming so we are leaving the reset as an output for the moment.
Maybe polling instead of pin interrupt? We will need to do more tests.
In the meantime, if you are an Avnet employee interested in getting a board please ping us :)
In this video the center LED (connected to reset pin) does not lite.
This is a video with the rework
jaromir.sukuba
icstation
Hulk