PCB that sends ambient temperature and high resolution analog data over a CAN bus for a FSAE electric car. Runs off a Teensy 4.0 and has connection pins for separate external analog sensors.

making a sensor where distance is proportional to analog output ex it distance is 5 mm output of dac is 405 if output is 50 mm dac out is 4095

The analog car design is a self-running electric car that avoids obstacle in the left-right region. The design is mainly supported with 5 circuit components. The 9 V to 5 V converted for voltage-current manipulations. The push-button delay circuit (kill switch) for users to temporarily be able to stop the car motors benefiting from RC circuit, MOSFET transistors, and 74HC14 Hex Schmitt Trigger Inverters. The motor speed controller using potentiometers, inverters, and generic diodes. As well as the HC-SR04 Ultrasonic Sensor circuit to sense the proximity of objects in a field of view.

Circuit Overview The circuit you're describing is a digital counter that uses an LDR (Light-Dependent Resistor) and a transistor to detect wheel rotations. The counter's output is then displayed on a seven-segment LED display. Here's a breakdown of the components and their roles: 1. Wheel Rotation Detection (LDR and Transistor) * LDR: The LDR acts as a sensor to detect changes in light intensity. You can mount it on the wheel' or near it, with a reflective or non-reflective surface attached to the wheel. As the wheel rotates, the LDR will be exposed to alternating light and dark conditions, causing its resistance to change. * Transistor: The transistor (e.g., a 2N2222 NPN BJT) is used as a switch or amplifier. The changing resistance of the LDR is used to control the base current of the transistor. When the LDR's resistance drops (more light), the transistor turns on, and when the resistance increases (less light), the transistor turns off. This converts the analog change in light into a digital ON/OFF signal (a pulse). 2. Counter (7490) * 7490 IC: This is a decade counter, meaning it can count from 0 to 9. The output of the transistor (the pulses) is fed into the clock input of the 7490. Each pulse represents one rotation of the wheel, and the 7490 increments its count accordingly. The 7490 has four outputs (Q0, Q1, Q2, Q3) that represent the BCD (Binary-Coded Decimal) equivalent of the count. 3. BCD to Seven-Segment Decoder (7446) * 7446 IC: The 7446 is a BCD-to-seven-segment decoder/driver. Its job is to take the 4-bit BCD output from the 7490 and convert it into a signal that can drive a seven-segment LED display. It has seven outputs (a, b, c, d, e, f, g), each corresponding to a segment of the LED display. 4. Seven-Segment LED Display * Seven-Segment Display: This display is used to show the count. The 7446's outputs are connected to the corresponding segments of the display. 5. Power Supply and Other Components * Power Supply: A regulated DC power supply (e.g., 5V) is needed to power all the ICs and components. * Resistors: Resistors are used for current limiting (e.g., for the LDR and the LED display) and biasing the transistor. * Capacitors: A capacitor might be used for debouncing the signal from the transistor to prevent multiple counts for a single rotation. Conceptual Connections Here is a step-by-step breakdown of how the components would be connected: * LDR and Transistor: * The LDR and a current-limiting resistor are connected in series across the power supply. * The junction between the LDR and the resistor is connected to the base of the NPN transistor. * The emitter of the transistor is connected to ground. * The collector of the transistor, with a pull-up resistor, becomes the output for the pulse signal. * Transistor to 7490: * The output from the transistor's collector is connected to the clock input of the 7490 IC. * The 7490's reset pins (MR and MS) should be connected to ground for normal counting operation. * 7490 to 7446: * The BCD outputs of the 7490 (Q0, Q1, Q2, Q3) are connected to the BCD inputs of the 7446 (A, B, C, D). * 7446 to Seven-Segment Display: * The outputs of the 7446 (a, b, c, d, e, f, g) are connected to the corresponding segments of the seven-segment display. * Crucially, you need to use current-limiting resistors (e.g., 330Ω) in series with each segment to protect the LEDs from high current. * The common terminal of the seven-segment display is connected to the power supply (for a common anode display) or ground (for a common cathode display). This setup creates a chain reaction: wheel rotation changes light, which changes LDR resistance, which turns the transistor on/off, generating a pulse. This pulse increments the 7490, and the 7490's output is decoded by the 7446, which then displays the count on the seven-segment LED.

ATMEGA328-PU (U1) Setup Power Supply Connections: Connect U1:VCC to U2:5V@1 (5V power supply). Connect U1:GND to U2:GND@1 (Ground). Connect U1:AVCC to U2:5V@2 (Analog Power Supply for better ADC performance). Multiple GND pins (U2:GND@1, U2:GND@2, U2:GND@3, U2:GND@4) should all be connected to a common ground plane for stability. Serial Communication for Debugging: Connect U1:PD0 (RX) to U6:TXD. Connect U1:PD1 (TX) to U6:RXD. These connections enable serial communication between the microcontroller (ATmega328) and the USB-Serial adapter (CH340N) for programming and debugging. Sensor Data Acquisition: Given the components, the MLX90614ESF-ACC-000-SP (U4) is an infrared temperature sensor that could be used for vital detection. It uses an I 2 2 C interface. Connect U1:PC4 (SDA) to U4:PWM_SDA. Connect U1:PC5 (SCL) to U4:SCL_Vz. This allows the ATmega328 to communicate with the MLX90614ESF infrared temperature sensor. Additional Considerations: An analog-to-digital converter (ADC) or a specialized RF module designed for UWB radar applications would be necessary to capture and process radar signals for detecting human vitals through walls. The MAX270CWP+ (U3) could be used for audio signal processing but may not directly apply to UWB radar signal processing. Power Supply to Other Components Connect U6:VCC to U2:5V@1. Connect U4:VDD to U2:5V@2. Ensure all components' ground pins are connected to the common ground plane (U2:GND@1, GND@2, GND@3, GND@4)

PCB that sends ambient temperature and high resolution analog data over a CAN bus for a FSAE electric car. Runs off a Teensy 4.0 and has connection pins for separate external analog sensors.