diff --git a/fw/lib_i2c.c b/fw/lib_i2c.c
index 521225b..1275d60 100644
--- a/fw/lib_i2c.c
+++ b/fw/lib_i2c.c
@@ -86,7 +86,7 @@ void i2c_scan(I2C_TypeDef* I2Cx, void (*onPingFound)(u8 address)) {
 //! I2C SEND FUNCTION
 //! ####################################
 
-u8 i2c_sendBytes_noStop(I2C_TypeDef* I2Cx, u8 i2cAddress, u8* buffer, u8 len) {
+u8 i2c_sendBytes_noStop(I2C_TypeDef* I2Cx, u8 i2cAddress, const u8* buffer, u8 len) {
 	u8 err = i2c_start(I2Cx, i2cAddress, 0); // Write mode
 	if (err) return err;
 	u32 timeout;
@@ -107,7 +107,7 @@ u8 i2c_sendBytes_noStop(I2C_TypeDef* I2Cx, u8 i2cAddress, u8* buffer, u8 len) {
 	return 0;
 }
 
-u8 i2c_sendBytes(I2C_TypeDef* I2Cx, u8 i2cAddress, u8* buffer, u8 len) {
+u8 i2c_sendBytes(I2C_TypeDef* I2Cx, u8 i2cAddress, const u8* buffer, u8 len) {
 	u8 err = i2c_sendBytes_noStop(I2Cx, i2cAddress, buffer, len);
 	//# Generate STOP condition
 	I2Cx->CTLR1 |= I2C_CTLR1_STOP;
diff --git a/fw/lib_i2c.h b/fw/lib_i2c.h
index 4b4aa16..f5b0e2b 100644
--- a/fw/lib_i2c.h
+++ b/fw/lib_i2c.h
@@ -23,8 +23,8 @@ void i2c_scan(I2C_TypeDef* I2Cx, void (*onPingFound)(u8 address));
 //! I2C SEND FUNCTION
 //! ####################################
 
-u8 i2c_sendBytes_noStop(I2C_TypeDef* I2Cx, u8 i2cAddress, u8* buffer, u8 len);
-u8 i2c_sendBytes(I2C_TypeDef* I2Cx, u8 i2cAddress, u8* buffer, u8 len);
+u8 i2c_sendBytes_noStop(I2C_TypeDef* I2Cx, u8 i2cAddress, const u8* buffer, u8 len);
+u8 i2c_sendBytes(I2C_TypeDef* I2Cx, u8 i2cAddress, const u8* buffer, u8 len);
 u8 i2c_sendByte(I2C_TypeDef* I2Cx, u8 i2cAddress, u8 data);
 
 //! ####################################