I’m working on a project to automate a gas geyser. The system consists of an Arduino Nano, a gas pressure sensor, and an electric arc circuit for ignition.
Project Overview: The gas pressure sensor is connected to a digital pin on the Arduino Nano and it interprets it as a binary signal (1 or 0) to indicate gas pressure. If pressure is detected, the Arduino should trigger the electric arc circuit to ignite the gas and start the geyser.
Issue: Whenever the electric arc circuit is activated, either manually or through the Arduino, the Arduino resets. The reset timing varies—sometimes it happens immediately, sometimes after a delay.
Here's the interesting part: If I disconnect the gas pressure sensor from the Arduino physically (removing the connection to pin 12 and ground), the reset doesn’t happen. The Arduino only resets when the gas sensor is connected. Even if just the ground wire/pin 12 is connected, the reset somehow still happens, although rarely. When both pin 12 and ground are connected, the reset happens mostly when the arc circuit is triggered. Additionally, the LCD shows gibberish after the reset.
I suspect this may be caused by electromagnetic interference (EMI) or some other form of electrical disturbance or maybe something else entirely. I am honestly clueless and I'm not sure how to resolve it. I’ve tried various solutions like using diodes and a tri-state buffer IC, but none have worked.
I’d appreciate any insights or suggestions to resolve this issue. If more information is needed, feel free to ask. I’ve also attached the circuit diagram for reference.
Sparks are used to send radio waves across the Earth, its powerful property is the very wide spectrum of frequensies so any wire in the World turns into an antenna, even that short piece to pin 12.
Have you placed it in a grounded metal enclosure? Here are some things to check:
Possible EMI (Electromagnetic Interference) Issue
This sounds like it could be related to EMI, either conducted or radiated. While I can't confirm this is the problem without more information, I also can't rule it out. Most MOS logic circuits are fast and sensitive to edge transitions. Minimizing lead lengths (which act as antennas) to less than 10 inches (25 cm) is crucial, as longer leads can pick up frequencies up to about 750 MHz, not accounting for reflections and other effects.
Tips to Reduce EMI:
Keep Connections Short: Both transmitters and receivers are affected by antenna length—longer antennas have greater gain and can pick up more interference. Use the KISS principle: Keep It Short & Simple.
Avoid Parallel Lines: Ensure power and logic lines are not running parallel to each other to minimize crosstalk and interference.
Use a Zero-Crossing Solid-State Relay: This can be a simple and effective solution to reduce EMI, especially when dealing with AC loads.
Historical Context: This issue has been known since the early 1960s with TCTL (Transistor-Coupled Transistor Logic), later known as TTL (Transistor-Transistor Logic). It prompted the development of line drivers and other technologies to manage EMI.
For further reading on related topics, check out these resources:
Triac Principles and Circuits, Part 1: Learn about triacs, which are often used in switching applications and can be susceptible to EMI. Read Part 1
Triac Principles and Circuits, Part 2: This article continues exploring triac applications and EMI considerations. Read Part 2
Arduino Forum Discussion on Flashing LEDs: An example of EMI considerations in a practical Arduino project.
To protect your electronics from electromagnetic interference (EMI), there are several strategies you can employ. EMI can cause malfunctions or degradation in performance if not properly mitigated. Here are some approaches you can consider:
1. Shielding
Shielded cables: Use cables with shielding (like braided metal or foil wraps) to reduce the amount of EMI they emit or pick up.
Enclosures: Place sensitive electronics in metal or conductive enclosures (Faraday cages) to block external electromagnetic fields.
2. Grounding
Proper grounding: Ensure that all electronic components and their enclosures are properly grounded to prevent stray electromagnetic signals from affecting them. Grounding can direct EMI away from sensitive components.
3. Ferrite Beads
Ferrite beads: Install ferrite beads on cables that run to and from sensitive electronics. These components help suppress high-frequency EMI by dissipating it as heat.
4. Twisted Pair Cables
Twisted pair wiring: If you're running wires, use twisted pair cables for signal lines. The twisting helps cancel out EMI that would otherwise be picked up by the wires.
5. Capacitors and Filters
EMI filters: Install EMI filters (low-pass, high-pass, or band-stop) on power supply lines or signal lines to prevent high-frequency noise from reaching sensitive electronics.
Capacitors: Capacitors between power lines and ground can help smooth out high-frequency noise.
6. Distance from EMI Sources
Separation: Keep sensitive electronics as far away as possible from sources of EMI, such as motors, ignitions, and power cables.
7. Proper Cable Routing
Avoid running signal cables near power lines, ignition systems, or any high-current cables to reduce the possibility of picking up interference.
8. Use EMI-Resistant Components
Whenever possible, use components that are specifically designed to be resistant to EMI, such as EMI-hardened sensors, controllers, and processors.
9. Suppress Noise at the Source
Suppress ignition noise: Use resistor-type spark plugs or ignition leads with built-in suppression to reduce EMI from the bike’s engine and ignition system.
DC-DC converters: For bikes with electric systems, install noise-suppressed DC-DC converters to minimize EMI from power supplies.
By implementing a combination of these techniques, you can significantly reduce the impact of EMI on your bike’s electronics. If you need help with a specific part or scenario, feel free to provide more details!
I am still confused what to do. Arduino only resets when there is a physical connection present. Close proximity really doesn't affect the circuit. Please suggest me the solution best tailored to my issue.
You could try using an opto coupler between the output of the Arduino and the input to your ark trigger. At least that would remove the direct connection to ground, which "might" offer a solution.
After moving the gas sensor further away from the electric arc circuit and twisting the wires from the gas pressure sensor, the Arduino no longer resets, so part of the issue has been resolved. However, the Arduino still resets when the electric arc circuit is activated via the relay controlled by the Arduino.
Current Observation: When the relay is activated, an LED on the PCB (which should remain off) flickers slightly, and the LCD begins displaying gibberish. Interestingly, when I move the electric arc circuit connections (with the circuit closed) further away from the relay (or generally from the whole setup), the LED stops flickering, and the LCD returns to normal.
I suspect that electromagnetic interference (EMI) or a similar disturbance is traveling through the wires and affecting the logic circuit via the relay.
Note: I have also twisted the wires from the electric arc circuit to the relay, but the resets are still happening.
I’m attaching an updated schematic of the circuit, clearly illustrating how the Arduino and relay are connected to the electric arc circuit.
I hope I’ve described the situation clearly. I’m still unsure what specific solution to implement as I have limited knowledge in electronics and would greatly appreciate any advice or suggestions to solve the exact issue.
