The Breakout Board exists to run limit switches, encoders, and analog sensors into the Thrifty Nova. This board breaks the 10 pin Data Port Connector into individual 3 pin connectors which break out 5V, the signal, and ground.
For the digital signals, a normally closed sensor will trigger a green LED when the sensor is opened. This was designed to compliment the Thrifty Hall Effect, so when the red LED on the Thrifty Hall Effect (normally on) turns off at the presence of a magnet, a green LED on this board turns on.
For the analog signal, an analog buffer and a resistor divider are present to gain the full resolution of a 5V signal such as the Thrifty Absolute Magnetic Encoder.
Connector Pin
Pin Type
Pin Function
1
Power
+3.3V
2
Power
+5V
3
Analog
Analog Input (0-3.3V)
4
Digital
Forward Limit Switch Input
5
Digital
Encoder B
6
Digital
Multi-function Pin
7
Digital
Encoder A
8
Digital
Reverse Limit Switch Input
9
Digital
Absolute Encoder Index
10
Ground
Ground
The motor runner board allows for reversing (via switch) and powering the motor (via the integrated slide potentiometer. The board sends a signal to the processor to enable it in "Slider Mode", turning off USB and CAN control. We designed this to make prototyping with brushless easier, just wire a ribbon cable to it and away you go!
Here is a link to the OnShape with the printed case included.
A limit switch is a device that detects the presence, absence, or position of an object by opening or closing an electrical circuit when a physical force is applied to its actuator (like a lever or button).
The Thifty Bot sells a normally closed version of this called the Thrifty Hall Effect, which is a contactless magnet-based limit switch that is omnidirectional with an LED for user feedback. For more info, see the product page here.
Position Sensing: Detects when the system reaches the end of its range.
Safety: Stops motors if the system they control moves into an unsafe position.
Protection: Prevents parts from moving too far and getting damaged.
Quadrature encoders are sensors that measure the position, speed, and direction of a rotating object using two signals that are 90 degrees apart.
Signal Generation: The rotating shaft produces two square waves.
Direction Detection: The order of the signals shows which way the shaft is turning.
Position Counting: Counts the pulses of the signals to determine position.
Resolution: More pulses per revolution mean more accurate measurements.
Absolute encoders provide a unique position value for each shaft angle, ensuring that the exact position is always known, even after a power cycle.
These encoders use Pulse Width Modulation (PWM) to convey position information. The position is encoded in the width of the pulses generated by the index pin.
Signal Generation: The encoder generates pulses with varying widths corresponding to the shaft's position.
Position Detection: The width of the PWM signal is measured to determine the exact position of the shaft.
Uses:
Precise Positioning: Ideal for applications requiring accurate and repeatable positioning. Think about controlling a swerve module's rotation or an arm's position.
These encoders provide position feedback as a continuous analog signal, typically a voltage or current that varies linearly with the position.
The Thrifty Bot sells one of these, and more info can be found at the product page here.
Signal Generation: The encoder produces a continuous analog signal (in the Nova's case, 0-3.3V) proportional to the shaft position.
Position Detection: The control system reads the analog signal to determine the exact position.
Continuous Feedback: Provides smooth and continuous position information.
Precise Positioning: Ideal for applications requiring accurate and repeatable positioning. Think about controlling a swerve module's rotation or an arm's position.