TechShop on DEV-09815 - Ardumoto - Motor Driver Shield

Vss suppose to be minimum 4.5V. How come you are able to hook it up with 3.3V?? The VIH (min) = 2.3V . So yes this board support 3.3V logic, but you don’t need to change Vss for that! :–/

Hope future version will fix this! :)