- The IO pins have an absolute maximum rating of 40 mA per pin.
- Also the following groups of pins should not have more than 100 mA drawn from them
* Digital pins 0 to 4
* Digital pins 5 to 1
* Analog pins A0 to A5
- In addition to that, the entire processor chip has a maximum rating of 200 mA current consumption.
The 7 segment LED displays are common cathode and the shift register is a 74HC595. I have included a photo of the 7 segment LED from the front showing the relationship between the pin numbers and the corresponding LED segment that the pin controls.