[TOC]
Table of contents
Table of contents
- Node Card Testing
- Visual Inspection
- Connectivity Testing
- Power Input/Output Tests
- ESP32 Communications Testing
- Node Card Auto Testing (Using Serial Monitor During Firmware Startup)
- Node Card Testing (Using Serial Monitor Testing Program)
- Node Card CAN Testing (Using Card Monitor Board)
- Node Card Output Line Testing (Using Card Monitor Board)
- Additional Notes from the Step-by-Step Assembly Guide
Node Card Testing
Visual Inspection
- Initial Check: Examine the board for any obvious issues like missing components, solder bridges, or components that are misaligned or not fully seated.
- Solder Joint Inspection: Use a magnifying glass or a microscope to inspect solder joints. Look for cold solder joints, insufficient or excessive solder, or any shorts between pads.
- Component Orientation: the IC’s are correctly oriented according to the PCB silkscreen or schematic.
Connectivity Testing
- Continuity Check: Use a multimeter in continuity mode to check for shorts between power rails and ground, and to ensure there are no open circuits in critical connections.
Power Input/Output Tests
Power input and output testing ensures that voltage levels are accurate, components are properly placed, and connections remain continuous across the Node Card’s power circuits. These tests verify the integrity of each power rail, helping identify any potential issues before installing sensitive components.
Perform each step below in sequence. When checking voltage (V), set a multimeter to DC voltage mode and measure across V+ and GND connections. For continuity checks (** Ω), switch the multimeter to **resistance mode and measure both ends of the connection to confirm a low-resistance path.
NOTE: Do not install the ESP32 until all voltages are verified to avoid potential damage.
NOTE: If the expected results are not met, consider the following actions:
- Re-verify the orientation of components listed in Pre-Reqs.
- Check soldering for poor connections or solder bridges between SMD legs and PTH pins.
- Temporarily remove optional components, such as protection diodes, to isolate the issue.
- Replace the component with a known good equivalent if the issue persists.
| Test Description | Pre-Reqs | Test Points | Expected Result |
|---|---|---|---|
| Verify GND Connection | None | BATT GND connection and NODE BUS GND pads |
Ω0 |
| Verify Blown Fuse Indicator | 1. Attach >14 VDC power supply with circuit protection to PWR IN ATX 5557 connector (J1, pins 1 and 2) 2. Check for Hot Components: Feel foroverheating components |
None | Red LED1 fades in/out indicating blown (or no fuse in FH1) and FUSE BYPASS is not selected |
| Verify No Short Circuits | 1. FUSE BYPASS (JP1) set to bypass the fuseusing a Jumper Cap 2. Verify orientation of protection diodes D1 and D9 |
PWR OUT (J4), across ATX 5557 V+ (pin 1) and GND (pin 2) |
1. Red LED1 is not on2. Match input voltage |
Verify POWER Indicators |
None | None | POWER indicators 3V3, 5 VDC, 12 VDC (Green LEDs) are all on |
Verify PWR IN Power Input Connections |
1. PWR INUSB-C socket (J2) using VDC+ (pins 2, 3) and GND (pins 1,4) 2. PWR IN DC-005 connector (J3) using VDC+/GND as labeled |
PWR OUT (J4), across ATX 5557 V+ (pin 1) and GND (pin 2) NODE BUS pads, across 12 VDC and GND pads |
Match input voltage13 |
Verify CAN BUS Power Input Connections |
Attach >14 VDC power supply to each of the CAN BUS RJ45 sockets (J5/J6): VDC+ (pins 3,4) and GND (pins 7,8) |
NODE BUS pads, across 12 VDC and GND pads |
Match input voltage1 |
Verify BATT Power Input Connection |
Attach >14 VDC power supply to BATT (JST XH, Screw/Spring Terminal, J12) pins 1,2 |
NODE BUS pads, across 12 VDC and GND pads |
Match input voltage1 |
| Verify 3A Fuse | 1. Remove FUSE BYPASS selection 2. Install 1808 3A fuse in fuse holder (FH1) 3. Attach power supply to one of the power input connectors |
PWR OUT (J4), across ATX 5557 V+ (pin 1) and GND (pin 2) |
Match input voltage1 |
Verify NODE BUS 12 VDC Pad |
1. Verify the orientation of the voltage regulator (VR1) | NODE BUS pads, across 12 VDC and GND pads |
~11.5 V1 |
Verify NODE BUS 5V Pad |
1. Verify orientation of filter capacitors C5 and C6 2. Verify orientation of protection diode D10 | NODE BUS pads, across 5 VDC and GND pads |
~5 V2 |
Verify 5 VDC OUT Connection |
Verify the USB-C socket alignment and soldering | 5 VDC OUT USB-C (J9), across V+ (pins 2,3) and GND (pins 1,4) |
~5 V2 |
Verify NODE BUS 3V3 Pad |
Verify orientation of diode D8 | NODE BUS pads, across 3V3 and GND pads |
~3.3 V3 |
Verify CAN BUS Termination |
n/a | CAN BUS (J5/J6) CAN-H (pin 1) and CAN-L (pin 2) |
>120 Ω4 |
Verify IO DEVICES Connection |
n/a | IO DEVICES (J7) pins 1-8 and NODE BUS GND tab |
0V |
Footnotes:
- 12 VDC Pad Voltage Drop: The expected output voltage is slightly lower than the input voltage (~0.5 VDC) due to SS310 protection diodes.
- 5 VDC Pad Voltage Drop: The 5V output voltage may show a minor variance from exactly 5V due to protective diode voltage drops.
- 3V3 Pad Voltage Drop: The 3V3 pad voltage may show a minor variance from exactly 3.3 VDC due to protective diode voltage drops.
- open circuit (>120 Ω): When only one CAN network device (e.g. LCC Node) is on the network, no CAN Network termination resistor is applied by the auto-termination circuitry.
ESP32 Communications Testing
This section confirms the functionality of both CAN Network and I2C Serial communication components and connections on the Node Card. Before testing, ensure the ESP32 module is installed only after verifying the 5 VDC power supply is present.
Use a multimeter to check for expected voltage levels during each step, following the sequence outlined below. For each test:
- Voltage checks: Set the multimeter to DC voltage mode and measure across the designated test points.
- Continuity checks (if applicable): Use resistance mode to confirm a low-resistance path.
Note: During testing, monitor the Red LED on the DevKit-C Module to confirm ESP32 power status.
| Test Description | Pre-Reqs | Test Points | Expected Result |
|---|---|---|---|
| Verify ESP32 Module | 1. Attach power supply to one of the power inputs 2. Verify ~5 VDC at ESP32 module (U2) across Vin and GND pins 3. Install DevKit-C Module (U2) while verifying orientation (USB connection position towards PCB right edge. Recommend using 19-Pin female headers for easy removal of the ESP32 module. |
n/a | Red LED power indicator on the DevKit-C Module is On. (If not, verify orientation and check voltage at Vin.) |
Verify CAN BUS Communication Connections |
1. Verify CAN transceiver (U1) orientation 2. Verify Ferrite Bead (FB3) is soldered correctly 3. Verify ESD Diodes (D6, D7) are soldered correctly | 1. CAN BUS (J5/J6) pins, CAN-H (pin 1) and GND (pin 3) 2. CAN BUS (J5/J6) pins, CAN-L (pin 2) and GND (pin 3) |
~2.25 VDC - 2.5 VDC (both lines similar during idle state) |
Verify CAN I/O Communications Connection |
1. Verify Ferrite Beads (FB5, FB6) are soldered correctly 2. Verify ESD Diode (D7) is soldered correctly | 1. CAN I/O (J11) pins, CAN-H and GND 2. CAN I/O (J11) pins, CAN-L and GND |
~2.25 VDC - 2.5 VDC (both lines similar during idle state) |
Verify NODE BUS I2C Communications |
1. Verify Ferrite Beads (FB3, FB4) are soldered correctly 2. Verify ESD Diode (D6) is soldered correctly | 1. NODE BUS tabs, SDA0 and GND 2. NODE BUS tabs, SCL0 and GND 3. NODE BUS tabs, SDA1 and GND 4. NODE BUS tabs, SCL1 and GND |
~3.3 VDC (both lines similar during idle state) |
Verify CAN BUS Termination |
1. Node Card is not connected to the CAN network 2. Verify voltage comparator (U3) orientation 3. Verify Zener Diode (ZD1) orientation 4. Auto-termination components (U3,ZD1,Q1,Q2,R3,R4,C7) are soldered correctly | CAN BUS (J5/J6) pins, CAN-H (pin 1) and CAN-L (pin 2) |
120$\Omega$ (when Node Card is the only device connected) |
Verify NODE REBOOT Tactile Button |
Press NODE REBOOT (S1) button once. When no button is installed, momentarily short pads 1 and 2 together |
n/a | ESP32 power (RED) LED turns off and then on (indicating a reboot) |
Node Card Auto Testing (Using Serial Monitor During Firmware Startup)
| Test Description | Pre-Reqs | Expected Result |
|---|---|---|
| Verify Firmware Startup with Serial Monitor | 1. Upload the ‘LCC Node Card’ firmware to the ESP32. 2. Attach power supply to any power input. 3. Insert DevKit-C Module (U2), ensuring the USB connection faces the right edge of the PCB. 4. Attach ESP32 to computer using USB cable.5. Open serial console, set the port (e.g., COM3) and baud rate (115200). |
[I] LCC Node: Started message is displayed |
| Verify Voltage To ESP32 | After completing starting of firmware with serial monitor | [W] Low Voltage from power supply to ESP32 message is NOT displayed |
| Verify 12 VDC To NODE BUS HUB | After voltage test completion | [W] Low Voltage from power supply to 12 VDC message is NOT displayed |
Verify NODE BUS I2C Communications (BUS A, BUS B) |
After voltage test completion | [I] I/O Card Communications is working message is displayed |
Verify NODE BUS CAN Communications |
After I2C communications test completion | [I] Successfully connected to CAN Network message is displayed |
**Verify I/O DEVICES Connectivity To Devices ** |
After CAN communications test completion | [I] Node Card I/O device found on connection nn messages for each device connected to the I/O Devices connector |
Node Card Testing (Using Serial Monitor Testing Program)
This table provides step-by-step instructions to verify the Node Card’s communication interfaces and I/O DEVICES functionality using the serial monitor testing program. Follow each test in sequence, and check “Expected Result” to confirm each test’s success.
| Test Description | Pre-Reqs | Action | Expected Result |
|---|---|---|---|
| Verify Testing Firmware | 1. Upload the ‘Testing’ firmware to the ESP32. 2. Attach power supply to any power input. 3. Insert DevKit-C Module (U2), ensuring the USB connection faces the right edge of the PCB. 4. Attach ESP32 to computer using USB cable. 5. Open serial console, set the port (e.g., COM3) and baud rate (115200). |
Enter m in the serial console input and send. |
Main Menu - LCC Fusion Project is displayed in the serial console. |
Verify NODE BUS I2C Communications (BUS A and BUS B) |
1. From the main menu, select Node Management by entering 1. 2. Choose Device Testing Management. 3. Select Test Node Card Connectivity. |
1. Connect NODE BUS tabs, SDA0 and SCL0 with a jumper wire. 2. Enter c to start the test.3. Repeat by connecting a jumper wire to NODE BUS tabs, SDA1 and SCL1and entering c to start the test again. |
Displays I2C Continuity Test Successful message. |
Verify NODE BUS CAN Communications |
After completing both I2C tests | 1. Connect NODE BUS CAN-H and CAN-L (PCB bottom) with a jumper wire. 2. Enter c to start the test. |
Displays CAN Continuity Test Successful message. |
**Verify I/O DEVICES Connectivity To Devices ** |
After CAN test completion | 1. Attach a multimeter or LEDs to I/O DEVICES pins 1-8 and NODE BUS GND. 2. Enter c to start test. Each pin will sequentially go HIGH (3.3 VDC) for 0.5 sec, repeating until s is entered. |
Multimeter reads 3.3 VDC or LEDs light up, one at a time. |
Node Card CAN Testing (Using Card Monitor Board)
If you connect the Node Card’s CAN Bus RJ45 to the Card Monitor Board, the LEDs will go flicker in response to CAN Bus activity.
| Lines | What you should see | How to read it |
|---|---|---|
| L1/L2 | ✴ Faint CAN Bus activity with traffic | Differential (CAN-H / CAN-L) bus; this is just a “there’s life” clue |
| L3/L6/L7 | ⛔ Off | Ground |
| L8 | 🟢 Always On (when bus-powered) | CAN Bus power present (12V+) |
| L4/L5 | n/a | Depends on how these 2 lines are configured to be used (optional, not defined by LCC specifications) |
Notes:
- These cards require the optional GND connection on the Card Monitor. Without it, the LEDs won’t light.
- This board is only a quick visual. Refer to the Node Card’s serial monitor and self-testing for more CAN status.
Node Card Output Line Testing (Using Card Monitor Board)
If you connect the Node Card’s I/O RJ45 to the Card Monitor Board, the LEDs will go on/off in response to on/off Events sent from the Node Card to the eight lines.
| Lines | What you should see | How to read it |
|---|---|---|
| L1–L8 | 🟢 ON at rest → OFF when pressed | Each line is pulled HIGH by default. Pressing the button pulls the line LOW to GND, turning the LED off. |
| L8 | ⚙ Either: ⛔ Always off (if configured as GND) 🟢 ON (when ON event is sent) |
Line 8 can be set as a normal input like the others, or as a ground reference for the button set. |
Configure Lines 7 and 8 using card’s LINE 8 jumpers (JP2 / JP3) to either GND or I/O
Additional Notes from the Step-by-Step Assembly Guide
Add these checks if you want a slightly safer bring-up, especially on first-time builds.
- Current-limit first power-on (bench supply): start low (example: 0.2–0.5 A). If the board behaves normally (no overheating, expected LEDs), raise as needed.
- ESP32 last: keep the DevKit-C module out until the Power Input/Output Tests pass.
- Thermal sanity check: after applying power, wait 5–10 seconds and check for any unexpectedly warm parts (regulators, diodes, fuse area).
- Reflow “bridge sweep”: after reflow, inspect fine-pitch pins on ICs and any tight-pitch connector pads for solder bridges.
- Mechanical stress check: verify RJ45 and USB-C connectors are square and solid; misalignment can create intermittent failures that look like “random” communication issues.