Debugger Circuit

The Debugger Circuit is part of the Ground Low-Voltage Systems. Its purpose it to provide easy debugging and analysis of the car’s safety and control systems.

The circuit is connected to all the low-voltage systems through the Low-Voltage Master Board and takes certain inputs from these systems such as fault indicators, voltage levels and transition states. A total of 17 inputs are fed to the debugging circuit.

It comprises of 15 opto-couplers that isolate the incoming HIGH/LOW signal to the micro controller. The controller used is an ESP-32S based Node MCU and only accepts 3.3VDC inputs while the actual inputs vary from 0 to 12VDC. Hence, PC817 optocoupler is used to ensure only 3.3VDC is input to the controller. LM317, a variable voltage regulator is used to step down the incoming signals to acceptable range.

For the analog voltage inputs, LM358 Operational Amplifier is used in voltage-follower mode to boost the signal, this is followed by a voltage divider. Since, the analog values range from 0 to 5VDC, this range is mapped between 0 and 3.3VDC for the microcontroller.

This data is then sent through the micro controller to an online database over the internet. All the inputs of the micro controller can be examined using a computer or smartphone connected to the internet.

Supplies

Components used:

Resistors

Capacitors

PCB mount-to-wire connectors

Headers

Optocouplers (PC817)

Operational Amplifier (LM358)

Microcontroller (NODE MCU-32S)

Supply Voltage: 12VDC

Step 1: Ordering the PCBs

Now we have got the PCB design and it’s time to order the PCB’s. For that, you just have to go to JLCPCB.com, and click on the “QUOTE NOW” button. JLCPCB has sponsored this project. JLCPCB (ShenzhenJLC Electronics Co., Ltd.), is the largest PCB prototype enterprise in China and a high-tech manufacturer specializing in quick PCB prototype and small-batch PCB production. You can order a minimum of 5 PCBs for just $2.

To get the PCB manufactured, upload the Gerber file you downloaded in the last step. Upload the.zip file or you can also drag and drop the Gerber files.

After uploading the zip file, you’ll see a success message at the bottom if the file is successfully uploaded. You can review the PCB in the Gerber viewer to make sure everything is good. You can view both the top and bottom of the PCB.

After making sure our PCB looks good, we can now place the order at a reasonable price. You can order 5 PCBs for just $2 but if it’s your first order then you can get 10 PCBs for $2. To place the order, click on the “SAVE TO CART” button.

My PCBs took 2 days to get manufactured and arrived within a week using the DHL delivery option. PCBs were well packed, and the quality was really good.