diff --git a/attiny85_firmware.ino b/attiny85_firmware.ino
new file mode 100644
index 0000000..1e92b3d
--- /dev/null
+++ b/attiny85_firmware.ino
@@ -0,0 +1,76 @@
+
+// Needs TMC2208Stepper library by teemuatlut
+#include <TMC2208Stepper.h>
+// Define pins
+#define EN_PIN 2  // LOW: Driver enabled. HIGH: Driver disabled
+#define rxPin 3
+#define txPin 0
+#define input_enable_motors 1
+TMC2208Stepper driver = TMC2208Stepper(rxPin, txPin);  // Create driver and use
+                                                  // Software Serial for communication
+void setDriversInternal_reff(int current_mA){
+  driver.push();                // Reset registers
+  driver.pdn_disable(true);     // Use PDN/UART pin for communication
+  driver.mstep_reg_select(true);
+  driver.microsteps(32);
+  driver.I_scale_analog(false); // Use internal voltage reference
+  driver.rms_current(current_mA);// Set driver current 200mA
+  driver.toff(5);               // Enable driver in software
+  driver.blank_time(24);
+  driver.intpol(1);
+  driver.TPOWERDOWN(128); // ~2s until driver lowers to hold current
+  //driver.hysterisis_start(3);
+  //driver.hysterisis_end(2);
+  //driver.pwm_lim(12);
+  //driver.pwm_reg(8);
+  driver.pwm_autograd(1);
+  driver.pwm_autoscale(1);
+  driver.pwm_freq(1);
+  //driver.pwm_grad(14);
+  //driver.pwm_ofs(36);
+  driver.en_spreadCycle(false);
+  driver.GSTAT(0b111); // Clear
+}
+
+void setDriversExternal_reff(){
+  driver.push();                // Reset registers
+  driver.pdn_disable(true);     // Use PDN/UART pin for communication
+  driver.mstep_reg_select(true);
+  driver.microsteps(32);
+  driver.IHOLD_IRUN(0x1F10);
+  driver.I_scale_analog(true);
+  driver.internal_Rsense(false);
+  driver.toff(3);               // Enable driver in software
+  driver.blank_time(24);
+  driver.intpol(1);
+  driver.TPOWERDOWN(128); // ~2s until driver lowers to hold current
+  driver.hysterisis_start(3);
+  driver.hysterisis_end(3);
+  //driver.pwm_lim(12);
+  driver.pwm_autograd(1);
+  driver.pwm_autoscale(1);
+  driver.pwm_freq(0);
+  driver.pwm_reg(3);
+  driver.pwm_grad(14);
+  driver.pwm_ofs(36);
+  driver.en_spreadCycle(false);
+  driver.GSTAT(0b111); // Clear
+}
+
+void setup() {
+  pinMode(input_enable_motors, INPUT);
+  pinMode(EN_PIN, OUTPUT);
+  digitalWrite(EN_PIN, HIGH);   // Disable driver in hardware
+  driver.beginSerial(9600);
+  setDriversExternal_reff();
+  //setDriversInternal_reff(200);// Set driver current 200mA
+}
+
+void loop() {
+ delay(500);
+ if(digitalRead(input_enable_motors)){
+  //setDrivers();
+  digitalWrite(EN_PIN, LOW);    // Enable driver in hardware
+ }
+ else digitalWrite(EN_PIN, HIGH);    // Disable driver in hardware
+}