Hi Werk_AG,
Thanks for your kind words. My background is a (retired) electronics engineer, primarily hardware, but I also spent many years writing microcontroller program code in Assembler. However, I was never "comfortable" moving to higher level languages such as C.
One of my present (long-term) "projects" is a microcontroller to "Add Solar logging to any FO station", which started before the WH-308x Solar Pods were even released! So it also might be relevant to Weatherduino. But my presence on this (and the Cumulus) forum might best be summarised as "To help make FO sensors better".
However, I'll just add a little to explain why the "Inverted input" Transimpedance configuration just discussed above might NOT be appropriate to this particular thread.
Personally, I distinguish between two types of "Photo Cell", which I would call a "Photo-Diode" and a "PV Panel". The first is basically a "detector" (with an active area up to perhaps 10 mm2), whilst the second is intended to generate power (with an area greater than say 10 mm2). But in principle, both can act like a photodiode and/or generate a current.
I have assumed that this thread title refers to the latter, but maybe I'm wrong? However, if I'm correct, then an inverted input transimpedance configuration is not really appropriate. The reason is that ALL the photocurrent must flow from the output of the Op-Amp and we have the slightly "silly" situation that as the PV panel generates more current, the load on the power supply rail increases. As I mentioned in #2 of the Davis thread, I was rather concerned that too much current might flow from their photodiode (unless it has a strong optical filter) and overload the amplifier/feedback resistor.
That's probably all to say for now (in this thread); I look forward to seeing the results of your labours in due course.
Cheers, Alan.
Thanks for your kind words. My background is a (retired) electronics engineer, primarily hardware, but I also spent many years writing microcontroller program code in Assembler. However, I was never "comfortable" moving to higher level languages such as C.
One of my present (long-term) "projects" is a microcontroller to "Add Solar logging to any FO station", which started before the WH-308x Solar Pods were even released! So it also might be relevant to Weatherduino. But my presence on this (and the Cumulus) forum might best be summarised as "To help make FO sensors better".
However, I'll just add a little to explain why the "Inverted input" Transimpedance configuration just discussed above might NOT be appropriate to this particular thread.
Personally, I distinguish between two types of "Photo Cell", which I would call a "Photo-Diode" and a "PV Panel". The first is basically a "detector" (with an active area up to perhaps 10 mm2), whilst the second is intended to generate power (with an area greater than say 10 mm2). But in principle, both can act like a photodiode and/or generate a current.
I have assumed that this thread title refers to the latter, but maybe I'm wrong? However, if I'm correct, then an inverted input transimpedance configuration is not really appropriate. The reason is that ALL the photocurrent must flow from the output of the Op-Amp and we have the slightly "silly" situation that as the PV panel generates more current, the load on the power supply rail increases. As I mentioned in #2 of the Davis thread, I was rather concerned that too much current might flow from their photodiode (unless it has a strong optical filter) and overload the amplifier/feedback resistor.
That's probably all to say for now (in this thread); I look forward to seeing the results of your labours in due course.
Cheers, Alan.