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Safe and Sound

23 Posts authored by: dougw Top Member
Observations & Surprises This project has been a very interesting journey researching a wide variety of invisible potential hazards, designing systems to measure invisible hazards, building wearable instrumentation and testing my environment to see what invisible hazards might be present. It is probably obvious from the content of my blogs that I learned a lot, actually way too much to fit into a few blogs, but the big surprise for me was how much fun it was. I anticipated the usual thrill ...
I have been waiting for a week to do some ultraviolet light tests - the sun just never seems to shine when I need it. I calibrated the UV sensor output to match the UV Index and wanted to test it in real sunlight. The UV Index was developed in Canada in 1992 and subsequently adopted by the World Health Organization and the World Meterological Organization in 1994. This table shows the UV Index scale and what it means: UV Index ................ Media graphic color Risk of harm from unprotec ...
It has been a very hectic week including a softball tournament on the weekend, but I did manage to squeeze in some work on calibrating my gas sensor module which is based on the TI MSP EXP432P401R launchpad. The 18 turn offset and gain pots on my custom sensor card make it easy to adjust the sensor outputs to fit any two point calibration. If linearization is needed, it would be done in software, however I don't have a way to map such curves yet. All sensors have been zeroed and the CO2 sensor ...
This week I've been sidetracked on a bit of a tangent to my build project. I was asked to make a presentation on invisible hazardous environmental factors. All I can say is the grapevine works in mysterious ways. Anyway I put together a 1 hour multi media presentation along with a show-and-tell demonstration of my instrumentation. The demo activity was beamed up onto the big screen using live video, so everyone could see the meters in giant scale going crazy when my cell phone was taken out ...
The deadline for this challenge has been extended again, so I can squeeze in a few more blogs. Perhaps some real applications of all this instrumentation I have put together. This blog shows some quick tests I did to see if shielding makes a difference to cell phone radiation. These tests are a follow up to an earlier blog on microwave radiation. To set up for the test, I made a shield from two 3D printed shells sandwiching a layer of aluminum foil between them. The shell and foil covered 5 o ...
This design challenge is nearing its final deadline so the pressure as been building to complete the project. I finally finished building all the hardware and all the hardware is working well. The past week has seen a lot of 3D design work and 3D printing and mechanical building, but also powered up the full system for the first time.   The subscriber power monitor is showing 5.08 volts at 10 mA. The publisher power monitor is showing 4.97 volts at 190 mA. Here are the four instruments ...
This update documents progress on power up of the custom gas and UV sensor module. I did run into a few snags getting the card to work, or rather getting the software to work. The hardware on the card is designed properly, but it has just been too long since I designed the card and my software assumptions were somewhat inexplicable. After backtracking my way through everything, I finally got it sorted out. I will post an update to my pinout table at the end of this blog in case anyone else has s ...
I have been under the weather this week, which is unusual for me. It is just so much fun trying to build electronics when you are feverish, nauseous, dizzy and coughing up a lung. None-the-less, the show must go on. The first thing I need to mention is the last item in the sponsored kit has arrived. (although I won't need it for this project) No video this week - my throat is too sore and I'm too hoarse and I'm coughing too much. I finally received enough parts to build my sensor booster pa ...
This is the last of the hazardous environmental factors research blogs for this project, subsequent blogs in this challenge will deal with hardware builds, software programs, functional tests and test results. Microwaves are used for cell phones, Wi-Fi, Bluetooth, Zigbee, GPS, some cordless phones, and microwave ovens. The microwave oven is proof that a high enough exposure can be harmful. But what is the mechanism that makes microwaves cook food? It is pretty common knowledge that it is heat ...
I have been in Washington making a technical presentation in an unbelievably secure building, but now I'm back and it is time to catch up. I am still waiting for some parts for my sensor card – it is starting to look like I will have to kludge some connectors and use lower performance amplifiers to get it working within the schedule. In the mean time I am using the working parts of the system to take some readings in my environment and I'm also doing a lot of 3D design and printing to mak ...
This last week has seen a lot of time on mechanical CAD and 3D printing to try and squeeze the MQTT subscriber system into a wearable package. I called it the ARM Car because it looks like a car and it is a TI ARM chip to be worm on an arm. Here is a picture of the ARM Car driving down the information highway: Starting with the high stack of circuit boards - it is non-trivial to figure out how to make it wearable: The package is assembled from 4 main plastic sections, a wrist bracket, a ba ...
I managed to purchase a second WiFi booster pack although the TI discount voucher I won here was not accepted This booster pack has allowed me to assemble a second system consisting of a  MSP-EXP432P401R a CC3100ModBoost and a  430BOOST-SHARP96 I have programmed the second system as an MQTT client subscribing to the IHEF data being published by my sensor platform which has the same cards plus my custom sensor booster pack Both systems use Wi-Fi to access my MQTT broker The following ...
Extremely Low Frequency Electromagnetic Radiation - (ELF) I am going to arbitrarily split this large topic into just the 2 ranges of electromagnetic fields which are of most interest to me: 0 to 300 Hz and microwaves from 2 to 3 GHz.   Is electromagnetic radiation dangerous to humans? There is no question that high electromagnetic fields are dangerous to humans. People can die from high voltage shocks such as lightning and high current such as an electric chair and is pretty obvious the ...
This blog shows the Booster Pack PCB I designed to accommodate 5 sensors. After viewing the video - I think it might have been cool to order a red card instead of green. The card was ordered from SeeedStudio and took exactly 7 days from time of order to arrive on my doorstep half way around the planet. I don't yet have all the components to assemble the card, but the card itself and the sensors have come in so I can show roughly how the sensors will be mounted.... This is the tenth blog in t ...
I have been in the throws of struggling with software and numerous other priority interrupts. Still ordering more parts and some have come in, but they will have to wait for another blog. I just have to get something posted even though it is not as complete as I had hoped. This installment describes a bit about trying to get an MQTT broker set up to handle sensor data from my wearable sensor suite. First, I wanted to install my own MQTT data broker so I can keep the data local for now. After ch ...