Add picocalc stm32 i2c keyboard code

Code/picocalc_keyboard/port.ino

@@ -0,0 +1,39 @@
+#include "port.h"
+
+void port_get_config_defaults(struct port_config *const config)
+{
+
+  /* Default configuration values */
+  config->direction  = PORT_PIN_DIR_INPUT;
+  config->input_pull = PORT_PIN_PULL_UP;
+
+}
+
+void port_pin_set_config(const uint8_t gpio_pin,const struct port_config *const config)
+{
+  if(config->direction == PORT_PIN_DIR_OUTPUT){
+    pinMode(gpio_pin,OUTPUT);
+    return;
+  }
+
+  if(config->direction == PORT_PIN_DIR_INPUT){
+
+    if(config->input_pull != PORT_PIN_PULL_NONE){
+      pinMode(gpio_pin,config->input_pull);
+    }else{
+      pinMode(gpio_pin,config->direction);
+    }
+  }
+}
+
+void port_pin_set_output_level(const uint8_t gpio_pin, const bool level)
+{
+  digitalWrite(gpio_pin,level);
+}
+
+
+bool port_pin_get_input_level(const uint8_t gpio_pin){
+
+  return digitalRead(gpio_pin);
+  
+}