Comments

Author Comment Last activity Moderation
david_uwi " spectrometer16f.gcb.txt " | Read more » almost 3 years ago
david_uwi "You've got to be careful with lasers. The visible lines are often not their main emission lines. For instance a green laser (532 nm) puts out more ..." | Read more » about 3 years ago
david_uwi "Yes you're quite correct in an ideal world we would be using absorbance (Log of transmission) and subtracting a blank. There is also a problem with..." | Read more » about 3 years ago
david_uwi " SPEC2018-2-.bmp This is the circuit diagram " | Read more » about 4 years ago
david_uwi "I am in Trinidad and Tobago. I have located the sensor outside, but sheltered from the weather. I am towards the eastern side of Trinidad and with ..." | Read more » over 4 years ago
david_uwi "I've come back to this after doing a bit more research on the subject. First as the device has sensitive op-amps which are exposed I have put an el..." | Read more » over 4 years ago
david_uwi " It's going from 0-250 ug/m3 (and the x-axis is 42 days).The average value (over 6 weeks) is 17 ug/m3. So the graph shows there are some large spik..." | Read more » over 5 years ago
david_uwi " Problem I have is that sucrose solution looks colorless so does not absorb visible light. I feel that the changes in absorbance that you are seein..." | Read more » over 5 years ago
david_uwi "Both glucose and sucrose solutions are colourless so visible light is not going to work. A homemade spectrometer will not go very far into the UV ,..." | Read more » over 5 years ago
david_uwi "I'm currently looking at the VEML6075 to detect UVA and UVB. It seems to be what I might call "semi-calibrated" that is you can use default setting..." | Read more » over 5 years ago
david_uwi "Finally got something working using the ic-Haus LFL1402 diode array. https://www.ichaus.de/iC-LFL1402 I normally use 3 V (2xAA bateries) so I had t..." | Read more » over 5 years ago
david_uwi "I've found that the clock timing with the Toshiba arrays is not quite as rigorous as suggested in the datasheet (I've only tried it with the TCD110..." | Read more » almost 6 years ago
david_uwi "There's something strange about your "spectrum" it seems to run green,yellow,pink,blue,green. Seems like there are several overlapping color patter..." | Read more » almost 6 years ago
david_uwi "When looking at this the only thing that comes to mind is WHY? " | Read more » about 6 years ago
david_uwi "Update: The diode array has gone from obsolete to unobtainable in a matter of a few months. I am testing an ILI1402 (made by ic Haus) which is supp..." | Read more » about 6 years ago
david_uwi "Sadly the diode array has also gone from "end of life" to obsolete to unobtainable. I'm getting the same problem with my design https://publiclab.o..." | Read more » about 6 years ago
david_uwi "Thanks for bringing this to prominence again. I will attach the code that runs the microprocessor. presslogger.txt This as mentioned above is wri..." | Read more » over 6 years ago
david_uwi "Oh well. I know about everyones strange reluctance to use microchip devices, but really they do not keep much of any value to the experimenter hidd..." | Read more » almost 7 years ago
david_uwi "I just use my programmer to read the falsh memory when it is getting full. The clcok crystal causes an wake-up (from sleep) interrupt when the time..." | Read more » almost 7 years ago
david_uwi "Yes it would seem that you could do it with an atmega 328 one of the timers supports the use of a clock crystal which will get your timing accurate..." | Read more » almost 7 years ago
david_uwi "I finally got round to making the Raman spectrometer. I first tried at right angles and as you found I got nothing. So I went for the transmission ..." | Read more » over 7 years ago
david_uwi "Yes I have no problem with that. It is however more involved than other projects I see on this site. It needs a lot of fine soldering (maybe a PCB..." | Read more » over 7 years ago
david_uwi "The display uses SPI communication (it has an internal ILI9341 driver). The PIC16F1788 has a hardware SPI module. These type of TFT displays can be..." | Read more » over 7 years ago
david_uwi "Here's a real spectrum which I stored on the SD card. It is of potassium permanganate. Because there is a very strong absorbance 500-580 nm and the..." | Read more » over 7 years ago