Due Dates:

• Requirements/Considerations - 4/7/2025

• Component Selection - 4/26/2025

• Initial Schematic - 7/2/2025

• Initial Layout - 7/10/2025

• Rev. A Ordered - 8/25/2025

• Firmware/Testing - 10/1/2025

  • breadboard sensors to verify correct resistances etc

Description/Purpose

Controls speed of water cooling pump and two fans. Additionally, interprets data from temperature sensors and flowrate sensors to send over CarCAN.

Requirements

• Pump (1x)

  • https://www.rigidhvac.com/store/products/12v-24v-pump-reservoir-combo-65mm

  • Receive FG signal and send PWM signal to/from pump

  • Requires +24V input (9.5W)

  • Selected because there’s basically no 24V PC pumps

• Fan (2x)

  • https://www.coolerguys.com/products/coolerguys-120mm-120x120x25-3000-rpm-ip67-24v-waterproof-fan-cg12025h24-ip67?srsltid=AfmBOoq3GbJD2-QdFyyd4g1RvQeUmcytZcuAu3ThIyLhBSjuGqU85IXB

  • 3 pin fan (+24V, TACH, GND)

  • Send PWM signal from fan control IC to NMOS based on TACH output

  • Selected w/ PTN for 24V + air volume

• Temperature sensors (3x but will likely only need 2)

  • https://koolance.com/sen-ap008b-coolant-temperature-sensor-brass-10k-ohm

  • 10k thermistor, use ADC to convert

  • Placed on the radiator

  • Selected bc PTN likes it

• Flow rate sensor (1x)

  • https://www.vegetronix.com/Products/Flow-Sensors/VG-FLOW-0_5/

  • 3 pin (+5V, GND, Flow_Out)

  • Flow_Out drives PMOS to get 3.3V frequency to psom

  • BSP fittings for less fluid leakage

  • Selected because decent documentation and versatile Vin

• Mechanical

  • Packaging

    • Enclosure contains pump board + pump

    • Coordinate with Nitish on ptn

  • All Connections (includes internal to enclosure)

    • **Recrimp all electronics to be fitted with molex nanofit

    • CarCANIn (1x2)

    • CarCANOut (1x2)

    • Flowrate (1x3)

    • Pump (1x4)

    • Temp1 (1x2)

    • Temp2 (1x2)

    • Temp3 (1x2)

    • Fan1 (1x3)

    • Fan2 (1x3)

    • LVPower (1x2)

    • 3.3VIn (1x2) - only for revA + internal to enclosure

    • 5VIn (1x2) - only for revA + internal to enclosure

    • PSOM - internal to enclosure

Application Note

how does this board integrate with others + any harnessing/bringup considerations. anyone should be able to read this and integrate this board into the electrical system

Context

Location of the board: Behind the driver

External Connection List

Main

Rev A Schematics

Open

Open

Open

Open

Open

Open

Circuit Components

all uniques (non-passives) in BOM + rationale for selection

• Fan control IC (1x)

  • https://ww1.microchip.com/downloads/aemDocuments/documents/MSLD/ProductDocuments/DataSheets/EMC2301-2-3-5-Data-Sheet-DS20006532A.pdf

  • Communicates with psom over I2C

  • Selected to remain consistent with BPS leader fan control

• PSOM

  • Selected because only need to communicate over CarCAN

  • Pins used:

    • FAN_SCL - PB6

    • FAN_SDA - PB7

    • TEMP1 - PA2 (ADC)

    • TEMP2 - PA4 (ADC)

    • TEMP3 - PA5 (ADC)

    • FLOW - PA6

    • SMBALERT - PB12

    • PUMP_FG - PB3

    • PUMP_PWM - PB10

Layout

PCB

Open

3D Model

Open

Open

Firmware

Drivers

High-Level (Block Diagram)