| Author | Comment | Last activity | Moderation | ||
|---|---|---|---|---|---|
| cfastie | "Hi Sara, Just about any handheld GPS device (e.g., Garmin) or any GPS app for a phone (I use GeoTracker) will record a track. The GPS coordinates ..." | Read more » | over 3 years ago | |||
| cfastie | "The Plantower sensors require 4.5 to 5.5 volts. They work well with 5 volt Arduinos. They might not work properly with ESP8266 or ESP32 boards beca..." | Read more » | over 3 years ago | |||
| cfastie | "I have not used a CCS-811 VOC sensor outdoors. That's mostly because I live in the woods in Vermont and the data would be boring. However the senso..." | Read more » | almost 4 years ago | |||
| cfastie | "`>> CCS-811 VOC sensors do not need regular calibration or initial calibration, as they use a different technique and not laser-scattering? ..." | Read more » | over 4 years ago | |||
| cfastie | "Here is some new data from a gas sensor. This is a module with a CCS-811 sensor (provides an estimate of total volatile organic compounds [VOC]). T..." | Read more » | over 4 years ago | |||
| cfastie | "The Adafruit VOC sensor module uses a CCS-811 VOC sensor. Modules with these sensors cost about half as much when purchased on eBay from sellers in..." | Read more » | over 4 years ago | |||
| cfastie | "Yes, any gas will be less dense when it is hotter and therefore will have more lift. If the gas inside the balloon is the same as the gas outside (..." | Read more » | over 5 years ago | |||
| cfastie | "Hi jeffalk, Thanks for pointing out that the PM10 index includes all particles smaller than 10µm. If that is true, you are correct that PM10 shoul..." | Read more » | over 5 years ago | |||
| cfastie | "If a device based on a Plantower sensor includes hardware that allows either live numerical display or data logging, it can be a very useful tool. ..." | Read more » | over 5 years ago | |||
| cfastie | "Liz, it's great to know that you (or I guess your Mom) were well coiffed in the 80s, although I regret that you did not include photographic eviden..." | Read more » | almost 6 years ago | |||
| cfastie | "Leslie, I will lend you anything you need. Tell me about your HEPA setup. You must already have a 5V Arduino, so all you need is three DuPont wires..." | Read more » | about 6 years ago | |||
| cfastie | "Thanks Nick. It's good to know about the duplicate sensors. That's an intriguing engineering decision. Chris " | Read more » | about 6 years ago | |||
| cfastie | "The field evaluation report linked above includes 78 graphs comparing the results of a Purple Air sensor with a $25k GRIMM optical particle counter..." | Read more » | about 6 years ago | |||
| cfastie | "There is another version of this sensor with the same specifications and the same price but it is about half the size. Does anyone know any reason ..." | Read more » | about 6 years ago | |||
| cfastie | "These might do the same thing for 10¢ apiece: https://www.ebay.com/itm/10Pcs-3-5mm-Female-Stereo-Audio-Socket-Headphone-Jack-Connector-5-Pin-PCB-Mo..." | Read more » | over 6 years ago | |||
| cfastie | "Kina, thanks for the videos. Very helpful. I might try CoolTerm again, since I was using a sketch that did not format the serial output in an appro..." | Read more » | over 6 years ago | |||
| cfastie | "I tried CoolTerm and never got it to work. I tried for only a half hour, so my failure is not so surprising. If you have a working data logger (e.g..." | Read more » | over 6 years ago | |||
| cfastie | "Liz, I don't know the specs of the 1/4" phone plug, but it needs only two contacts, the tip and one ring along the shaft. I'm not sure which types ..." | Read more » | over 6 years ago | |||
| cfastie | "New answer below where I could attach a file. " | Read more » | over 6 years ago | |||
| cfastie | "A 1/4" stereo/phone plug connects to the HCHO sensor and two wires from that cable connect to the Arduino (tip of plug to A3, ring to GND). Below (..." | Read more » | over 6 years ago | |||
| cfastie | "The first step might be to arrange for the co-location of the HCHO sensor, an Arduino, and somebody casually familiar with Arduino. Has the proper ..." | Read more » | over 6 years ago | |||
| cfastie | "Kina, Thanks for the great information. Liz, It might help to know more about this project. What is the time frame for deployment? What has been tr..." | Read more » | over 6 years ago | |||
| cfastie | "There is a very simple way to read the HCHO sensor with a resolution of about 10 ppb, assuming the range of the sensor is 0 to 1000ppb. (Out of the..." | Read more » | over 6 years ago | |||
| cfastie | "I think it is par for the course that a random proprietary sensor will not work gracefully with an Arduino. In this case, it might be that a standa..." | Read more » | over 6 years ago |