TUNIS board description
Signal processing
In this section, the signal processing part of the board will be described.
TUNIS board - Analog inputs and outputs
Warning
Analog and digital inputs of a STM32 microcontroller (included on the Nucleo board) operate on voltages between 0 and 3.3V. Otherwise inputs can lead to severe damages.
Function |
Label |
Type |
Pinout on Nucleo |
|---|---|---|---|
Analog Input 1 |
E1 / EA0 |
Analog or Digital Input |
PA_0 / A0 |
Analog Input 2 |
E2 / EA1 |
Analog or Digital Input |
PA_1 / A1 |
Analog Output 1 |
S1 / DAC1 |
Analog or Digital Output |
PA_4 / A2 |
Analog Output 2 |
S2 / DAC2 |
Analog or Digital Output |
PA_5 / D13 |
Warning
When the analog output S2 is in use, LED1 on the Nucleo board becomes unavailable (it is also connected to D13 or PA_5).
All other pins on the Nucleo board remain available for your application and can be connected directly to the Arduino or Morpho connectors.
DC Motor position control
In this section, the DC motor position control part of the board will be described.
TUNIS board - DC motor connector
Pinout of the Nucleo board
Function |
Label |
Type |
Pinout on Nucleo |
|---|---|---|---|
PWM 1 |
PWM 1 |
Digital Output |
PB_6 / D10 |
PWM 2 |
PWM 2 |
Digital Output |
PC_7 / D9 |
Motor Error (Driver) |
EF |
Digital Input |
PA_7 / D11 |
Encoder Channel A |
SA |
Digital Input |
PB_8 / D15 |
Encoder Channel B |
SB |
Digital Input |
PB_9 / D14 |
Connection to the motor
During labworks, Pololu DC motor (3239 or 4843) are used. This gearmotor consists of a 12 V brushed DC motor combined with a 20.4:1 metal gearbox. A 48 CPR quadrature encoder is integrated on the motor shaft. It provides 979.62 counts per revolution of the gearbox’s output shaft.
More documentation is available at the Pololu website : POL3239 or POL4843
Pololu DC motor connector - From pololu.com
Color |
Function |
|---|---|
Red |
Motor power (connected to one motor terminal) |
Black |
Motor power (connected to the other motor terminal) |
Green |
Encoder GND |
Blue |
Encoder VCC (5V) |
Yellow |
Encoder A output |
White |
Encoder B output |
Power supplies
Caution
Pololu motors 3239 and 4843 support a voltage until 12V.