Sends a value to the seven segment display
The input value is converted into an uint16_t integer. If the input value is smaller than 0 it is set to 0 if it is bigger than 0xffff it is limited to this value. The value is then displayed in hexadecimal form on the seven segment display
Arduino card number must be 1 for the moment
The example below shows a counter whose value is displayed on a plot as well as on the seven segment display.