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NXPCUP-Shield-FRDM-MCXN947 Assembly Guide

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Assembly Steps Overview

  1. Component Preparation
  2. Soldering Resistors
  3. Soldering Capacitors
  4. Soldering Diode
  5. Soldering IC Sockets
  6. Soldering Header Connectors
  7. Soldering JTAG Connectors
  8. Soldering XT60 Connector
  9. Soldering Screw Terminals
  10. Soldering 2-pin and 3-pin Connectors
  11. Soldering Potentiometer
  12. Soldering Switch
  13. Soldering DIP Switch
  14. Mounting DC-DC Converter
  15. Mounting Motor Drivers
  16. Inserting LM339 ICs
  17. Mounting Jumper
  18. Final Verification
  19. PCB Cleaning

Before You Begin

Safety Precautions

  • Wear safety glasses when soldering
  • Keep soldering iron in a safe stand when not in use
  • Avoid touching the soldering iron tip
  • Wash hands after handling solder (especially lead-based)

Soldering Tips

  • Use appropriate temperature (300-350°C for lead-free solder)
  • Clean the tip regularly on a damp sponge
  • Apply solder to the joint, not the iron
  • Heat both the pad and component lead
  • Use just enough solder for a shiny, cone-shaped joint
  • Allow joints to cool naturally (don't blow on them)

Step 1: Component Preparation

Checklist

Verify that you have all electronic components from the Shield Components table:

Organize Your Workspace

  1. Lay out all components in groups
  2. Label small containers for cut-off leads
  3. Have your tools ready and accessible
  4. Ensure good lighting
  5. Keep the PCB clean and free from debris

Step 2: Soldering Resistors (R1-R20)

Instructions

  1. Identify positions R1-R20 on the PCB silkscreen
  2. Bend the leads:
    • Use the resistor body width as a guide
    • Bend leads at 90° directly next to the resistor body
  3. Insert resistors:
    • Push through the PCB holes
    • Resistors can be mounted in either direction (no polarity)
    • Ensure the resistor body sits flush against the PCB
  4. Secure the component:
    • Bend the leads slightly outward on the bottom to hold in place
  5. Solder the joints:
    • Heat both the pad and the lead for 2-3 seconds
    • Apply solder to create a shiny, cone-shaped joint
    • Remove solder first, then the iron
  6. Trim excess leads:
    • Use flush cutters to trim close to the solder joint
    • Cut at a slight angle away from the joint

Quality Check

  • All 20 resistors are soldered
  • Solder joints are shiny and cone-shaped
  • No cold solder joints (dull, grainy appearance)
  • No solder bridges between adjacent pads
  • Leads are trimmed flush

Note: Resistors have no polarity and can be mounted in any direction.

Step 3: Soldering Capacitors (C1-C5)

Instructions

  1. Identify positions C1-C5 on the PCB
  2. Insert capacitors:
    • Ceramic capacitors have no polarity
    • Insert leads through the marked holes
    • Push until the capacitor body touches the PCB
  3. Secure and solder:
    • Bend leads slightly on the bottom side
    • Solder each lead using the same technique as resistors
  4. Trim excess leads:
    • Cut flush with the solder joint

Quality Check

  • All 5 capacitors are soldered
  • Capacitors sit flat against the PCB
  • Solder joints are clean and shiny
  • No excess solder or bridges

Note: Ceramic capacitors have no polarity.

Step 4: Soldering Schottky Diode (D1)

Instructions

  1. Identify position D1 on the PCB
  2. ⚠️ CHECK POLARITY:
    • The diode has a band marking on one end (cathode)
    • The PCB has a corresponding marking (usually a line or band)
    • The band on the diode MUST match the marking on the PCB
  3. Insert the diode:
    • Align the band with the PCB marking
    • Double-check orientation before soldering
    • Push the diode body close to the PCB
  4. Solder the leads:
    • Solder both leads securely
  5. Trim excess leads

Quality Check

  • Diode polarity is correct (band matches PCB marking)
  • Both leads are soldered properly
  • Diode body is close to PCB surface

⚠️ CRITICAL: Incorrect diode orientation will prevent the circuit from working and may cause damage!

Step 5: Soldering IC Sockets (for U4-U7)

Instructions

  1. Identify positions U4-U7 on the PCB
  2. Orient the sockets:
    • Each socket has a notch or dot indicating pin 1
    • Match this with the marking on the PCB
    • ⚠️ Correct orientation is critical!
  3. Insert sockets:
    • Place socket into the PCB holes
    • Ensure all pins go through the holes (check for bent pins)
    • Socket should sit flat against the PCB
  4. Secure the socket:
    • You can tape the socket in place or use helping hands
    • Solder one corner pin first
    • Check alignment, reheat if needed to adjust
  5. Solder all pins:
    • Solder the opposite corner pin
    • Then solder all remaining pins (14 pins per socket)
    • Ensure each pin has a good solder joint

Quality Check

  • All 4 sockets (U4-U7) are installed
  • Socket notches match PCB markings
  • Sockets sit flat and perpendicular to PCB
  • All 56 pins (14 pins × 4 sockets) are soldered
  • No solder bridges between pins

Note: Do NOT insert the LM339 integrated circuits into the sockets yet. This will be done in Step 16.

Step 6: Soldering Header Connectors (J1, J2, J5, J6)

J1 - 2x10 Pin Connector

  1. Identify position J1 on the PCB
  2. Insert the connector:
    • Align all 20 pins with the holes
    • Ensure the connector is perpendicular to the PCB
    • The plastic base should sit flush on the PCB
  3. Secure the connector:
    • Solder one corner pin
    • Check alignment and adjust if needed
    • Solder the opposite corner pin
  4. Solder all pins:
    • Solder all remaining 18 pins
    • Ensure good solder flow on each pin

J2, J5 - 2x8 Pin Connectors

  1. Identify positions J2 and J5
  2. Insert each connector (16 pins per connector)
  3. Solder using the same technique:
    • Corner pins first for alignment
    • Then all remaining pins

J6 - 2x6 Pin Connector

  1. Identify position J6
  2. Insert the connector (12 pins)
  3. Solder all pins

Quality Check

  • J1 (2x10) is soldered - 20 pins
  • J2 (2x8) is soldered - 16 pins
  • J5 (2x8) is soldered - 16 pins
  • J6 (2x6) is soldered - 12 pins
  • All connectors are perpendicular to PCB
  • No solder bridges between pins
  • All pins have good solder joints

Tip: These connectors will mate with the FRDM-MCXN947 board, so proper alignment is crucial.

Step 7: Soldering JTAG Connectors (J7-J9)

Instructions

  1. Identify positions J7, J8, J9 on the PCB
  2. Check orientation:
    • JTAG connectors typically have a pin 1 indicator
    • Match this with the PCB marking (usually a square pad or marking)
  3. Insert connectors:
    • Each connector has 2x5 pins (10 pins total)
    • Ensure all pins align with holes
    • Connectors should be perpendicular to the PCB
  4. Solder each connector:
    • Solder one corner pin first
    • Check alignment
    • Solder opposite corner
    • Solder all remaining pins (10 pins per connector)

Quality Check

  • All 3 JTAG connectors (J7-J9) are installed
  • Pin 1 orientation is correct on each
  • Connectors are perpendicular to PCB
  • All 30 pins (10 pins × 3 connectors) are soldered
  • No solder bridges

Note: J7 and J8 are used for line sensor connections, J9 is used for camera connection.

Step 8: Soldering XT60 Connector (J10)

Instructions

  1. Identify position J10 on the PCB
  2. ⚠️ CHECK POLARITY:
    • XT60 connectors have + (positive) and - (negative) markings
    • The PCB will have corresponding markings
    • Verify correct orientation before soldering!
  3. Insert the connector:
    • Align the connector with the PCB holes
    • Ensure it sits flush against the PCB
    • The connector body should be stable
  4. Solder the pins:
    • XT60 pins are large and require more heat
    • Heat the pin and pad for 3-5 seconds
    • Apply sufficient solder for a strong joint
    • Both pins must be solidly soldered

Quality Check

  • XT60 connector polarity is correct (+ and - match PCB)
  • Connector sits flush on PCB
  • Both pins have strong, shiny solder joints
  • No cold solder joints (these carry high current)

⚠️ CRITICAL: This connector carries battery power. Incorrect polarity or poor solder joints can cause serious damage or fire hazard!

Step 9: Soldering Screw Terminals (J11, J12)

Instructions

  1. Identify positions J11 and J12 on the PCB
  2. Orient the terminals:
    • The screw holes should face outward (away from the PCB center)
    • This allows easy access for connecting motor wires
  3. Insert terminals:
    • Push the pins through the PCB holes
    • Ensure the terminal body sits flat on the PCB
  4. Solder the pins:
    • Solder each pin (2 pins per terminal)
    • These terminals carry motor current, so ensure good joints

Quality Check

  • Both screw terminals (J11, J12) are installed
  • Screw holes face outward for easy access
  • All 4 pins (2 per terminal) are soldered
  • Terminals sit flat on PCB

Note: These terminals will connect to the DC motors.

Step 10: Soldering 2-pin and 3-pin Connectors (J13-J15, J17)

Instructions

  1. Identify positions:
    • J13: 3-pin connector
    • J14: 2-pin connector
    • J15: 2-pin connector
    • J17: 3-pin connector
  2. Insert each connector:
    • Align pins with PCB holes
    • Ensure connectors are perpendicular
  3. Solder all pins:
    • J13: 3 pins
    • J14: 2 pins
    • J15: 2 pins
    • J17: 3 pins

Quality Check

  • J13 (3-pin) is soldered
  • J14 (2-pin) is soldered
  • J15 (2-pin) is soldered
  • J17 (3-pin) is soldered
  • All connectors are perpendicular to PCB
  • Total 10 pins soldered

Step 11: Soldering Potentiometer (RV1)

Instructions

  1. Identify position RV1 on the PCB
  2. Insert the potentiometer:
    • Align the 3 pins with the PCB holes
    • The adjustment screw should be accessible
    • Push until the body sits on the PCB
  3. Solder the 3 pins:
    • Ensure good solder joints on all pins

Quality Check

  • Potentiometer is installed at RV1
  • All 3 pins are soldered
  • Adjustment screw is accessible
  • Component sits flat on PCB

Note: This potentiometer adjusts the line sensor detection threshold.

Step 12: Soldering Switch (S1)

Instructions

  1. Identify position S1 on the PCB
  2. Insert the slide switch:
    • Align the pins with the PCB holes
    • Ensure correct orientation
    • The switch should sit flat on the PCB
  3. Solder all pins:
    • Solder each pin securely
    • This is the main power switch, so good joints are important

Quality Check

  • Switch is installed at S1
  • All pins are soldered
  • Switch operates smoothly
  • Switch sits flat on PCB

Note: This is the main power on/off switch for the shield.

Step 13: Soldering DIP Switch (SW1)

Instructions

  1. Identify position SW1 on the PCB
  2. Check orientation:
    • DIP switches usually have a marking for position 1
    • Match this with the PCB marking
  3. Insert the DIP switch:
    • Align all 8 pins with the PCB holes
    • Ensure the switch sits flat
  4. Solder all 8 pins:
    • Solder one corner pin first
    • Check alignment
    • Solder remaining pins

Quality Check

  • DIP switch is installed at SW1
  • Correct orientation (position 1 marked)
  • All 8 pins are soldered
  • Switch sits flat on PCB
  • All 4 switches operate smoothly

Note: This 4-position DIP switch is used for configuration settings.(keep position 3 in ON state, do not use)

Step 14: Mounting DC-DC Converter (U1)

Instructions

  1. Identify position U1 on the PCB
  2. Prepare the MP1584EN module:
    • Check the module pinout: IN+, IN-, OUT+, OUT-
    • ⚠️ Verify connections before soldering!
  3. Position the module:
    • Align the module pins with the PCB pads
    • Ensure correct orientation (IN+ to IN+, etc.)
    • The module should sit flat or at the designated height
    • Connection between power source and shield is made through 4 connectors of 2 pins each
  4. Solder the connections:
    • Solder IN+ pin
    • Solder IN- pin
    • Solder OUT+ pin
    • Solder OUT- pin
    • Use sufficient solder for good electrical and mechanical connection
  5. Adjust output voltage (if needed):
    • Before final assembly, you may need to adjust the output voltage
    • Use the onboard potentiometer on the MP1584EN
    • Set to 5V output (measure with multimeter)
    • ⚠️ Verify voltage before mounting any chips or connecting shield to FRDM board!

Quality Check

  • MP1584EN module is installed at U1
  • Correct orientation (IN+, IN-, OUT+, OUT- match PCB)
  • All 4 connections are soldered (4 connectors of 2 pins each)
  • Output voltage is set to 5V (if adjustable)
  • Module is mechanically secure

⚠️ IMPORTANT: This module converts battery voltage (7.4V) to 5V for the logic circuits. Incorrect wiring can damage components!

Step 15: Mounting Motor Drivers (U2, U3)

Instructions

  1. Identify positions U2 and U3 on the PCB
  2. Prepare the DRV8833 modules:
    • Each module is a dual H-bridge motor driver
    • Check the pinout on the module
    • Identify: VCC, GND, IN1, IN2, IN3, IN4, OUT1, OUT2, OUT3, OUT4
  3. Position the first module (U2):
    • Align all pins with the PCB pads
    • ⚠️ Verify correct orientation!
    • Ensure the module sits flat or at the correct height
  4. Solder all pins for U2:
    • Solder one corner pin first
    • Check alignment
    • Solder all remaining pins
  5. Repeat for the second module (U3):
    • Same procedure as U2
  6. Verify connections:
    • Check that power pins (VCC, GND) are correctly connected
    • Check that control pins (IN1-IN4) match the PCB design
    • Check that output pins (OUT1-OUT4) go to motor terminals

Quality Check

  • DRV8833 module is installed at U2
  • DRV8833 module is installed at U3
  • Both modules have correct orientation
  • All pins are soldered on both modules
  • No solder bridges between pins
  • Modules are mechanically secure

Note: These drivers control the DC motors. U2 controls one motor, U3 controls the other.

Step 16: Inserting LM339 Integrated Circuits (U4-U7)

Instructions

  1. Prepare the LM339 ICs:
    • Take the 4 LM339 quad comparator ICs
    • ⚠️ Handle with care - these are static sensitive!
    • Each IC has 14 pins
  2. Check IC orientation:
    • Each LM339 has a notch or dot marking pin 1
    • The IC sockets (U4-U7) also have notch markings
    • The notch on the IC MUST match the notch on the socket
  3. Prepare IC pins (if needed):
    • IC pins may be slightly splayed outward
    • Gently bend pins inward by pressing the IC sideways on a flat surface
    • Pins should be perpendicular to the IC body
  4. Insert the first IC (U4):
    • Align the IC notch with the socket notch
    • Align all 14 pins with the socket holes
    • Press down gently but firmly
    • All pins should enter the socket
    • Do not force! If a pin bends, remove the IC and straighten the pin
  5. Verify insertion:
    • The IC should sit flat in the socket
    • No pins should be bent or outside the socket
  6. Repeat for U5, U6, and U7:
    • Same procedure for each IC
    • Always check notch orientation!

Quality Check

  • LM339 IC is inserted in socket U4 (notch aligned)
  • LM339 IC is inserted in socket U5 (notch aligned)
  • LM339 IC is inserted in socket U6 (notch aligned)
  • LM339 IC is inserted in socket U7 (notch aligned)
  • All ICs sit flat in their sockets
  • No bent pins
  • All pins are in the socket (none outside)

⚠️ CRITICAL: Incorrect IC orientation will prevent the circuit from working and may damage the IC when powered!

Step 17: Mounting Jumper

Instructions

  1. Identify the jumper position on the PCB
    • Locate connector J15 on the PCB
    • This jumper selects the camera power source
  2. Mount the jumper:
    • Place the jumper on J15
    • The jumper connects two adjacent pins
  3. Verify configuration:
    • Jumper on J15 selects 5V power for the camera (J9)
    • This is the recommended configuration

Quality Check

  • Jumper is installed on J15
  • Jumper configuration is correct (5V camera power)

Note: The jumper on J15 provides 5V power to the camera connector (J9).

Step 18: Final Verification

Visual Inspection

  1. Component check:

    • All resistors (R1-R20) are installed
    • All capacitors (C1-C5) are installed
    • Diode D1 is installed with correct polarity
    • All IC sockets (U4-U7) are installed with correct orientation
    • All header connectors (J1, J2, J5, J6) are installed
    • All JTAG connectors (J7-J9) are installed
    • XT60 connector (J10) is installed with correct polarity
    • Screw terminals (J11, J12) are installed
    • All auxiliary connectors (J13-J15, J17) are installed
    • Potentiometer (RV1) is installed
    • Switch (S1) is installed
    • DIP switch (SW1) is installed
    • DC-DC converter (U1) is installed with correct orientation
    • Motor drivers (U2, U3) are installed with correct orientation
    • LM339 ICs are inserted in sockets with correct orientation
    • Jumper is installed

  2. Solder joint inspection:

    • All solder joints are shiny (not dull or grainy)
    • All joints have a cone shape (not ball-shaped or flat)
    • No cold solder joints
    • No solder bridges between adjacent pins or pads
    • No excess solder creating blobs
    • All component leads are trimmed flush

  3. Component orientation check:

    • Diode D1 band matches PCB marking
    • IC socket notches match PCB markings
    • LM339 IC notches match socket notches
    • XT60 connector polarity is correct
    • DIP switch position 1 is correctly oriented
    • DC-DC converter IN/OUT connections are correct
    • Motor driver modules are correctly oriented

Electrical Verification with Multimeter

⚠️ IMPORTANT: Perform these tests BEFORE connecting battery!

  1. Continuity test:

    • Set multimeter to continuity mode (beep)
    • Test critical connections:
      • GND connections are continuous
      • Power traces are continuous where expected

  2. Short circuit test:

    • Set multimeter to resistance mode
    • Test between power and ground:
      • Measure resistance between XT60 + and - terminals
      • Should read > 1kΩ (typically several kΩ)
      • If reading is very low (< 100Ω), there may be a short circuit!
    • Test between 5V and GND:
      • Should also read > 1kΩ

  3. Diode test:

    • Set multimeter to diode test mode
    • Test D1:
      • Forward direction should show ~0.3-0.5V (Schottky diode)
      • Reverse direction should show "OL" (open/infinite)

  4. IC socket continuity:

    • Verify that IC socket pins have continuity to their respective PCB traces
    • Spot-check a few pins on each socket

Quality Standards

Good solder joint characteristics:

  • Shiny, smooth surface
  • Cone or volcano shape
  • Solder flows onto both pad and component lead
  • No gaps or voids
  • Adequate but not excessive solder

Bad solder joint indicators:

  • Dull, grainy appearance (cold joint)
  • Ball-shaped (insufficient heating)
  • Solder only on lead or only on pad (poor wetting)
  • Cracks or fractures
  • Excess solder creating bridges

Troubleshooting Common Issues

Problem: Cold solder joint

  • Solution: Reheat the joint, ensure both pad and lead are heated

Problem: Solder bridge between pins

  • Solution: Use desoldering wick to remove excess solder

Problem: Component not sitting flush

  • Solution: Reheat joint, press component down, let cool

Problem: Lifted pad

  • Solution: Be very careful! May need to run a jumper wire

Problem: Short circuit detected

  • Solution: Inspect for solder bridges, check component orientation

Shield Assembly Complete! ✓

Congratulations! You have successfully assembled the NXPCUP-Shield-FRDM-MCXN947.

Next Steps

The shield is now ready to be mounted on the FRDM-MCXN947 board and integrated into the car chassis.

Next: Car Assembly Guide →

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