diff --git a/.gitmodules b/.gitmodules
deleted file mode 100644
index 10c17dc..0000000
--- a/.gitmodules
+++ /dev/null
@@ -1,3 +0,0 @@
-[submodule "firmware/slider/SliderCommunication"]
-	path = firmware/slider/SliderCommunication
-	url = https://gitlab.tubit.tu-berlin.de/dsp_labor_ws1819/SliderCommunication.git
diff --git a/protocol/Readme.md b/protocol/Readme.md
new file mode 100644
index 0000000..71563cb
--- /dev/null
+++ b/protocol/Readme.md
@@ -0,0 +1,4 @@
+This folder contains template implementations for the communication master and slaves. 
+
+It also defines the data packet that is exchanged on each poll. This definition is
+used in the actual slave firmware. 
\ No newline at end of file
diff --git a/protocol/communication.h b/protocol/communication.h
new file mode 100644
index 0000000..8db2bd1
--- /dev/null
+++ b/protocol/communication.h
@@ -0,0 +1,29 @@
+/*
+ * communication.h
+ *
+ * Describes the data packet sent for each channel
+ */
+#pragma once
+#include "interface.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+typedef struct {
+        uint16_t poti[4];
+        uint16_t slider;
+        uint8_t button:1;
+} message_t;
+
+/// END OF MESSAGE == MSB is set
+#define IS_EOM(b) (b & (0x80))
+
+
+// defines the message length of a slave message in bytes
+// NOTE: sizeof(message_t) is 12 because of the 4-byte alignment criteria
+#define SLAVE_MESSAGE_LEN (5*2+1)
+
+#ifdef __cplusplus
+} // end extern "C"
+#endif
diff --git a/protocol/interface.h b/protocol/interface.h
new file mode 100644
index 0000000..de400ce
--- /dev/null
+++ b/protocol/interface.h
@@ -0,0 +1,24 @@
+#pragma once
+
+#include <stdint.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+typedef uint8_t byte_t;
+
+// this struct describes a communication interface
+typedef struct iface {
+	// callback, gets called when data arrives at interface
+	void (*on_read)(struct iface *, byte_t, void*ptr);
+	void *callback_data;
+
+	void (*write)(struct iface *, byte_t);
+} iface_t;
+
+
+#ifdef __cplusplus
+} // end extern "C"
+#endif
+
diff --git a/protocol/master/master.c b/protocol/master/master.c
new file mode 100644
index 0000000..c68bb87
--- /dev/null
+++ b/protocol/master/master.c
@@ -0,0 +1,62 @@
+/*
+ * master.c
+ *
+ *  Created on: 06.12.2018
+ *      Author: julian
+ */
+
+#include "master.h"
+#include "../communication.h"
+
+void on_receive(iface_t * me, byte_t b, void*ptr)
+{
+	master_t * this = (master_t*)(ptr);
+
+	if (this->msg_byte_counter >= 0) {
+		if (this->msg_byte_counter <=8) {
+			static uint16_t temp = 0;
+			if (this->msg_byte_counter%2) {
+				temp |= (b<<7);
+
+				switch(this->msg_byte_counter) {
+				case 1:
+				case 3:
+				case 5:
+					this->buffer[this->chain_len].poti[this->msg_byte_counter/2] = temp;
+					break;
+				case 7:
+					this->buffer[this->chain_len].slider = temp;
+					break;
+				}
+			}else {
+				temp = b&0x7F;
+			}
+		} else {
+			this->buffer[this->chain_len].button = b&0x01;
+		}
+	}
+
+	this->msg_byte_counter++;
+	if (!(this->msg_byte_counter = (this->msg_byte_counter+1)%SLAVE_MESSAGE_LEN)) {
+		this->chain_len++;
+	}
+
+	// decode package
+	if (IS_EOM(b)) {
+		return;
+	}
+
+	// keep communication running
+	me->write(me, 0x00);
+}
+
+void master_init(master_t *master, iface_t * dev)
+{
+	dev->on_read = on_receive;
+	dev->callback_data = master;
+
+	// initialize master values
+	*master = struct {
+		.iface = dev,
+	};
+}
diff --git a/protocol/master/master.h b/protocol/master/master.h
new file mode 100644
index 0000000..e4cd9fd
--- /dev/null
+++ b/protocol/master/master.h
@@ -0,0 +1,36 @@
+/*
+ * master.h
+ *
+ *  Created on: 06.12.2018
+ *      Author: julian
+ */
+
+#ifndef __DSPLAB_COMMON_MASTER_H__
+#define __DSPLAB_COMMON_MASTER_H__
+
+#include "../slave/slave.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+// how many channels we can encounter AT MOST
+#define MAX_CHAIN_LEN 10
+
+// this structure defines one complete chain
+typedef struct {
+	iface_t * iface;
+
+	message_t buffer[MAX_CHAIN_LEN];
+
+	int chain_len;	//< measured chainlength
+	int msg_byte_counter; //< bytecounter of receiver
+} master_t;
+
+void master_init(master_t *master, iface_t * dev);
+
+#ifdef __cplusplus
+} // end extern "C"
+#endif
+
+#endif /* __DSPLAB_COMMON_MASTER_H__ */
diff --git a/protocol/slave/slave.c b/protocol/slave/slave.c
new file mode 100644
index 0000000..82babd3
--- /dev/null
+++ b/protocol/slave/slave.c
@@ -0,0 +1,48 @@
+/*
+ * slave.c
+ *
+ * this is a default implementation for a slave
+ * it will continously encode its state on request
+ */
+
+#include "slave.h"
+#include "../communication.h"
+
+
+// implementation for slave_encode
+void slave_encode(iface_t *iface, int16_t s) {
+	iface->write(iface, (s>>0)&0x7F);
+	iface->write(iface, (s>>7)&0x7F);
+}
+
+void slave_on_receive(iface_t * me, byte_t buffer, void *ptr)
+{
+	slave_t * slave = (slave_t*)ptr;
+
+	if (!IS_EOM(buffer)) {
+		me->write(me, buffer);
+		return;
+	}
+
+	me->write(me, buffer & 0x7F);
+
+	// write state
+	// write potis
+	for (int i = 0; i < 4; i++)
+		slave_encode(me, slave->state.poti[i]);
+
+	// write slider
+	slave_encode(me, slave->state.slider);
+
+	me->write(me, 0x80 | (slave->state.button & 0x01));
+}
+
+void slave_init(slave_t *slave, iface_t *iface)
+{
+	iface->on_read = slave_on_receive;
+	iface->callback_data = slave;
+
+	slave->iface = iface;
+	slave->state = (message_t){};
+}
+
diff --git a/protocol/slave/slave.h b/protocol/slave/slave.h
new file mode 100644
index 0000000..e917a3e
--- /dev/null
+++ b/protocol/slave/slave.h
@@ -0,0 +1,36 @@
+/*
+ * slave.h
+ *
+ * contains a slave definition
+ */
+
+#pragma once
+
+#include "../communication.h"
+#include "../interface.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+// this struct describes one chain in the link 
+typedef struct
+{
+	iface_t * iface;
+	message_t state;
+} slave_t;
+
+// The slave will use this method to encode 
+// one adc sample
+void slave_encode(iface_t *iface, int16_t s);
+
+// initialize the slave 
+void slave_init(slave_t *slave, iface_t *iface);
+
+
+
+#ifdef __cplusplus
+} // end extern "C"
+#endif
+
+