Critique Request: Hardware Design of Vending Self-Service Car Wash Machine

Projects General Guidance
1

Hello Everyone,

If you have time to spare, I would greatly appreciate any feedback on my hardware design/diagram. I have only done this project in Wokwi simulation only and I have yet to proceed to developing the actual hardware of the vending machine. I don't have much experience in hardware development aside from the Arduino Car Kit. I am afraid of burning Arduino Uno R3 and relay modules if I proceed without caution and proper knowledge.

I am situated at Philippines and the standard outlets here are rated at 220V 60Hz. I am currently trying to develop and program a vending self-service car wash machine. This would be my first project for deployment. I am trying to use Arduino UNO R3 to control 4 electrical outlets (250VAC-10A) via a 4-channel relay module (SLA-5VDC-SL-C) in which 1 electrical 1.5 HP induction motor (220VAC) and 3 solenoid valves (220VAC) would be plugged in. I have some questions regarding my harware design/diagram:

  • Do I have the right and sufficient power supply for the project?
  • Is it safe to connect the 4-gang outlet in parallel from the live (red) and neutral (gray) wire of switching power supply?
  • Does the connection of 4-gang outlet to the 4-channel relay module is safe and would not burn the 4-channel relay module?
  • Since solenoid valve produce a voltage kickback, do I still need to connect a kickback/snubber diodes (1N4007) between the relays and outlets?
  • What component/s would you replace in the hardware diagram?

This is my hardware diagram:

Vending Machine Hardware Diagram.drawio
Vending Machine Hardware Diagram.drawio1342×663 46.6 KB

This is the links of my components I would be using:
Power Supply
4-Channel Relay Module
AC Outlets
Solenoid Valves
1.5HP Induction Motor
High Pressure Water Pump
Universal Coin Slot

Please note that this is the 4th revision of my design. If you have read my previous post on Critique Request: Vending Self-service Car Wash Machine Sketch, there may be mismatching information.

This is my first post and version of the project in Tinkercad before being introduced to Wokwi simulation and guided on how I can improve my design approach by Alto777.

Thank you very much in advance. Looking forward to your insights!

2

Feeding 12 volt to the barrel plug and then tapping the 5 volt pin is bad. The 5 volt onboard converter will overheat. Feed 5 volt to the 5 volt pin.

3

Thank you very much for your advice. Should I power the 4-channel relay module and LCD I2C directly from the 5V output of switching power supply since I would be using the 5V pin of Arduino UNO R3 as a voltage input to bypass the 5V regulator?

4

Yes.

1 Like
5

@thecodeisbugged pleas flag your other thread and ask a moderator to add it to this or vice versa.

This helps helpers know you, your project goals and what you've accomplished so far.

It makes works for us answering the sam questions or looking through your other thread(s).

At the very least, when you mention other threads it would be polite to make them links to those threads.

But really this is one project - some go on for dozens of posts and the evolution of the design makes for good reading.

TIA

a7

6

Thank you very much for pointing out how I can make most of my post and make it much more easier to understand. I apologize once again for the lack of information. I'll be working on it.

7

Starting with Arduino: My Recommended Approach

It seems you might not be fully ready to start the project just yet, but that’s perfectly okay! We don't know your skill set or what resources you have at your disposal, so I recommend starting with some online tutorials. While the quality varies, many tutorials are excellent and will help you build a solid foundation.

Here’s How to Get Started:

  1. Learn the Basics: Begin with the fundamentals, such as controlling outputs (like LEDs) and interpreting inputs (such as reading a switch or receiving a message). LEDs are a great starting point since they’re inexpensive and most Arduino boards come with a built-in LED.
  2. Explore Basic Electronics Tutorials: Look for beginner-friendly tutorials on electronics concepts. These will help you understand key principles that you’ll need as you progress.
  3. Recommended Resources:
  • Arduino Cookbook: Consider going through the Arduino Cookbook, which is a comprehensive guide filled with practical projects and step-by-step instructions.
  • Online Tutorials: Check out YouTube channels like CodeBeauty for easy-to-understand lessons presented in small, digestible parts.
  • Embedded: Arduino Interrupts Tutorial & Examples
  • Get some help from somebody local that knows your codes and has experience in mains power. Doing this we will live another day.
  1. Learning the IDE: During this process, you will also learn what an IDE (Integrated Development Environment) is and how to use it to write, generate, and upload your code to the Arduino.
  2. Practice and Learn at Your Own Pace: Everyone learns at different speeds, and that’s completely normal. It may take a few months to grasp the basics, but with consistent practice, you’ll see progress.

Additional Help:

Please keep us updated on your journey, and don’t hesitate to ask questions as you learn. We’re here to help and guide you along the way!

8

Thank you very much for providing the sources of tutorials and topics to study. I'll be adding this to the list of what I am currenlty studying for this project.