diff --git a/src/lib.rs b/src/lib.rs
index 1ef6109..d0135ae 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1,2 +1,10 @@
 #![no_std]
 
+use embedded_hal::i2c::SevenBitAddress;
+
+pub const I2C_ADDR: SevenBitAddress = 0b0_0110100;
+
+pub struct TCA8418<I2C> {
+    i2c: I2C,
+}
+