Comments

Author Comment Last activity Moderation
cfastie "This is very clever. I wonder whether the memory in a Atmega 328p can be used to store data. I wonder if it is possible to access those data later...." | Read more » about 5 years ago
cfastie "There is a growing list of logger options and specs in a Google sheet. Please add information there if you know other stuff. " | Read more » about 5 years ago
cfastie "That Openlog is tiny! It combines an Arduino 328p with a microSD card, but still needs an RTC. There are clones of it available for $7.00. I have ..." | Read more » about 5 years ago
cfastie "Are you interested in the difference between a blue filter and a red filter? A blue filter could be referred to as NGB (red is blocked and NIR repl..." | Read more » about 5 years ago
cfastie "I am not familiar with the optics equations. My approach would be to enable precise adjustments of the components and find the best resolution (cri..." | Read more » about 5 years ago
cfastie "Yes, we are going to change the pixel values in our photo. For each pixel in the photo we have taken of vegetation, we use the DN in the red channe..." | Read more » about 5 years ago
cfastie "I think the Public Lab Infragram camera has a red filter, so the red channel will capture mostly red light. The blue channel will capture mostly NI..." | Read more » about 5 years ago
cfastie "Update: The u-blox NEO-7M board can be powered with either 3.3 or 5 volts. The GPS module itself is not tolerant of more than 3.6 v, but the board ..." | Read more » about 5 years ago
cfastie "That's a good result from Infragram.org. The result could be different outside because the color of the light can influence the proportion of visib..." | Read more » about 5 years ago
cfastie "I guess I demonstrated that the u-blox is protected someway or another from voltage over the stated 3.6v max. I was using four eneloop AAA (4 x 1.2..." | Read more » over 5 years ago
cfastie "Some blue filters including Wratten 47, Schott BG3, and Rosco 2007 are dual bandpass red-rejection filters. They require that blue light be used fo..." | Read more » over 5 years ago
cfastie "Stitching Mobius photos can be hard. The longer lens will help. Correcting the distortion afterwards can help. A high shutter speed and vibration d..." | Read more » over 5 years ago
cfastie " The red filters typically used do not transmit much green light, so the green channel captures mostly NIR. Some yellow filters pass red and green,..." | Read more » over 5 years ago
cfastie "I have not worked with water chemistry sensors, but your first impression might be a good one -- a device that can send encoded concentrations of N..." | Read more » over 5 years ago
cfastie "With certain red filters replacing the NIR cut filter, instead of red, green, and blue channels, you get red+NIR, NIR, and NIR channels. Without ad..." | Read more » over 5 years ago
cfastie "When the NIR cut filter is removed from a camera, all three color channels capture NIR light in addition to the color they originally captured (R, ..." | Read more » over 5 years ago
cfastie "Those male + female headers would be really handy. This is the first time I have used a Nano without headers, and it makes a really tidy package fo..." | Read more » over 5 years ago
cfastie "Hi Liz, The components wired together weigh 33 grams and the bracket weighs 8 g. The batteries to power it weigh a lot more than that. A case with ..." | Read more » over 5 years ago
cfastie "The text file attached above gives the correct RGB values for the NDVI_VGYRM lookup table. I put an image of the NDVI_VGYRM color gradient in my an..." | Read more » over 5 years ago
cfastie "I think the algorithm to convert a blue- or red-filtered NIR photo to color NDVI is something like this: Start with a color photo in which one ch..." | Read more » over 5 years ago
cfastie "Peegar is an academic project at the University of Tokyo which provides browser-based graphical programming of a microcontroller. It "uses audio c..." | Read more » over 5 years ago
cfastie "Regarding using a battery with voltage near the top of the acceptable range, apparently some voltage regulators convert the voltage to the desired ..." | Read more » over 5 years ago
cfastie "I don't know how low the voltage has to get before the Riffle starts to misbehave. @Donblair designated the 3.5v to 6v range, so he must have based..." | Read more » over 5 years ago
cfastie "What are the voltage requirements: are there upper and lower limits? The silkscreen on the Riffle says 3.5v to 6v for the "general" power connecti..." | Read more » over 5 years ago