TC4+
Analog
In
CH2- CH2+ CH1- CH1+ CH4- CH4+ CH3- CH3+
Figure 4: Layout of the thermocouple channels on the TC3 board.
3
Connecting to your roaster
This section will briefly list how to connect the TC4+ to the most common
accessories. Figure 3 shows the location and layout of all connectors and status
LEDs on the TC4+. See the end of the section for a complete application
example.
3.1
Connecting to the Arduino
Stack the TC4+ shield on top of an Arduino Uno R3, or compatible. The long
pins on the underside of the TC4+ go into the corresponding headers on the
top side of the Arduino.
3.2
Connecting thermocouples
The TC4+ provides four thermocouple channels. These are provided in an 8-
pin screw terminal near the “north” edge of the board. Due to board layout
constraints, the order of the pins is not ascending, but in order CH2-, CH2+,
CH1-, CH1+, CH4-, CH4+, CH3-, CH3+. See Figure 4 for details.
Usually, you will want to use one K-type thermocouple probe each to measure
bean temperature (BT) and air temperature (ET). Connect ET to channel 1,
and BT to channel 2. Positive and negative wires need to be correct - if you see
wrong temperature readings, try reversing the wires. If you thermocouple probe
comes with a plug, remove it either by unscrewing if possible or else cutting it
off.
3.3
Connecting to DC power
The DC IN terminal can be connected to a DC power supply. This will supply
power to two things: Firstly, to the TC4+ and the connected Arduino. Secondly,
to a connected DC motor (or other DC load). If you intend to connect a DC
5
