MM Defender IOT Controller Construction Details

MM Defender IOT Controller Add-On Construction Details

This is a rather large topic under construction. Current progress is about 5%.

Recent posts on the Mosquito Magnet Forum have described a replacement controller that any DIY type can build and install. Poor quality control plus harsh outdoor environments has lead to some controllers becoming faulty with age. Additionally, the original controller makes it quite difficult to troubleshoot a non-working trap. Many have been wishing for a replacement that can help keep these marvelous devices working into the future. The MM Defender IOT Controller article describes one approach, but is lacking details on how to actually construct and implement the device. This article will supply more details. It is, however, necessary to discuss a few matters regarding this MM Defender IOT Controller design, which partially explains why this topic was not written earlier.

Hazard Warning

First, the Mosquito Magnet traps use propane gas, which is flammable, and therefore dangerous. The original trap designers took great pains to make sure the trap would be safe. This is why the trap shuts down if everything is not "just so." While frustrated users being bitten might say that the designers were being overly conservative and unnecessarily cautious, DIYers have not done the extensive analysis that is customary for a manufacturer of a potentially dangerous device.

Making and deploying a substitute controller, or any modification of a dangerous device, can be regarded as a risky or even reckless action. If something goes wrong, and there is an explosion, poisoning, or other calamity resulting in loss of life and limb, or property damage, do you want to have had a hand in the chain of events that even possibly might have caused it?

Second, the construction, modification, and installation requires tools and instruments plus experience with PCBs and micro component soldering. Those without the right tools or skills will find this project too difficult. Once modified, it is relatively easy but *not* trivial to revert to the original controller. If the modified system does not work, you may be stuck. Additionally, other than the PIC microcontroller, the original controller must be working because those the IOT Controller Add-on just substitutes for the PIC. However, it is the failure of some of the parts of the original controller that might have caused the problems in the first place. The add-on controller is helpful to identify those issues.

Third, the controller is an experimental device intended for use by experts to troubleshoot a non-working trap, and not as a permanent replacement for the original controller. As presently implemented, it lacks important features required for a permanent deployment. These are, in part, adequate mechanical support (mounting to the device), weatherproofing, and of course, safety and functionality certification and validation. Currently, the controller is supported only by the wires connecting it to the original controller PCB. Because it is not fully insulated, it must be positioned just so to avoid shorting to the trap metal parts. Although electrical insulation and some weatherproofing could be mostly jury-rigged by covering the controller with a plastic bag, this is not what anyone would call a real solution.

Because it is an experimental device, it should be easily accessible for updating or substitution, which is done quickly to avoid excessive mosquito bites while doing so. This requires removing the catch basket and top cover. It is not easy to remove the top cover screws, so some may choose leave the screws out, which presents another potential hazard.

Under no circumstances do we want anyone to endanger any life or property. Any servicing or modification of the trap is a dangerous undertaking. You should label any modified trap with a warning. Once your trap is working reliably, you should uninstall the controller add-on and revert to the original, unless you are engaged in active development. Remember, the add-on will not work reliably over the years due to lack of mechanical support and weatherproofing.

These remarks, of course, apply to all DIY modifications, not just this one, which is intended only for troubleshooting and development. Be cautious even if you improve upon the design.

Basic Steps

1. #Assemble Tools and Supplies
2. #Test and Fix the Original Controller
3. #Acquire Materials
4. #Set up Development PC & Software
5. #Program and Test Module(s)
6. #Build the Wiring Harness
7. #Modify the Controller PCB
8. #Attach the Harness
9. #Initial Test Outside Trap
10. #Install Modified Controller into Trap
11. #Move Trap to Operating Location
12. #Final Test
13. #Monitor from PC and Phone

Assemble Tools and Supplies

You will need the following tools, equipment, and supplies:

• 10x (opt. plus 50x) Stereo Microscope with illumination to clearly see what you are doing.
• Soldering iron with micro tip.
• Solder, solder flux, fine solder wick, PCB cleaner, alcohol, and brushes for cleaning.
• Micro tweezers for surface mount device (SMD) placement and manipulation.
• A medical syringe is helpful for prying and scraping.
• Volt-Ohm Meter (VOM) with suitable test leads.
• Oscilloscope, single or dual channel, calibrated, with probes. 10 MHz or higher. 1 MHz might work with allowances, not tested.
• Diagonal cutter and wire stripper for fine (e.g., 20-28) gauge wire.

Test and Fix the Original Controller

If the original controller is not working, or even if it is, it is a good idea to remove it, clean it, and inspect it thoroughly.

• Measure the resistance to ground

Set up Development PC & Software

1. Connect the Expressive NodeMCU Module to the PC via USB
   1. If necessary, install the CP2102 Drivers to create a new COM port