Thermocouple Sensor v1.0 and Extruder Controller v2.2

I just received my Thermocouple Sensor v1.0, Extruder Controller v2.2 and RepRap Motherboard v1.2 from MakerBot.

I am looking at the documentation and I cant find were I should connect the Thermocouple Sensor v1.0 to the Extruder Controller v2.2. I suspect I should be using the A6 or A7 header.

In the reprap-gen3-firmware-1.4 i found the file Extruder.pde i found the function get_temperature()

/**
 *  Samples the temperature and converts it to degrees celsius.
 *  Returns degrees celsius.
 */
int get_temperature()
{
#ifdef THERMISTOR_PIN
  return read_thermistor();
#endif
#ifdef THERMOCOUPLE_PIN
  return read_thermocouple();
#endif
}

The only place I found the THERMISTOR_PIN is in Configuration.h but it is under this section

/****************************************************************************************
 * Sanguino Pin Assignment
 ****************************************************************************************/

//these are the pins for the v2.0 Extruder Controller
#if defined(EXTRUDER_CONTROLLER_VERSION_2_0) || defined(EXTRUDER_CONTROLLER_VERSION_2_1) || defined(EXTRUDER_CONTROLLER_VERSION_2_2)

#define ENCODER_A_PIN 2
#define ENCODER_B_PIN 3

#define RX_ENABLE_PIN 4
#define TX_ENABLE_PIN 16

#define MOTOR_1_SPEED_PIN 5
#define MOTOR_1_DIR_PIN 7
#define MOTOR_2_SPEED_PIN 6
#define MOTOR_2_DIR_PIN 8

#define SERVO1_PIN 9
#define SERVO2_PIN 10

#define HEATER_PIN 11
#define FAN_PIN 12
#define VALVE_PIN 15

#define THERMISTOR_PIN 3

#define DEBUG_PIN 13

#endif

My guess is that I need to comment out "#define THERMISTOR_PIN 3" and add "#defineT HERMOCOUPLE_PIN".

The pin on the chip for ADC is 19 but the thermistor input ADC3 is on pin 26 not like in the file.

What number should I use for ADC6 on a Extruder Controller v2.2 ?

Hi

I think the thermistor is read with an Arduino Analogue Read statement which uses the ADC pin reference so defining Thermister pin as 3 is correct and is actually referring to physical pin number 26.

Therefore I think you need to modify code to:-

//#define THERMISTOR_PIN 3 commented out
#define THERMOCOUPLE_PIN 3


I have not checked this but I believe it is correct.

You may have to cut out R6 and C8 as I think they are only needed for the thermistor.

You will also need to make sure you have the signal connected to the terminal that is tracked to pin 26 and you will have to find a 5 volt supply. I think the thermocouple may have been overlooked when the extruder v2.2 was designed.

A good reference is the Arduino connections and firmware in the generation 2 electronics.

---

Regards

Ian

Before removing parts on my PCB I want to try using the A6 or A7 inputs.

If I look at the pin assignment there is:
ENCODER_B_PIN 3 witch is D3 (pin 1 PD3 in the schematic)
THERMISTOR_PIN 3 witch is A3 (pin 26 PC3 (ADC3) in the schematic)

following this logic I will try
//#define THERMISTOR_PIN 3
#define THERMOCOUPLE_PIN 6

and see if I get A6 (pin 19 ADC6 in the schematic)

OK I see. That looks good as there is a header with the connections needed. Let me know if it works as I want to use a thermocouple instead of thermistor.

---

Regards

Ian