[Solved] PIC12C508 light dimmer app. note EN011202 ? - Page 1
Forum section: electronics / general

author: shakalnokturn
author_rank: Super Contributor
timestamp: November 03, 2023, 01:06:14 am
content: I know half of you are going to be telling me that the device is long obsolete and so on... No worries, I'm not going to be using it.Does anyone have a copy of the the Microchip EN011202.PDF application note?It seems to have vanished from internet.

author: jpanhalt
author_rank: Super Contributor
timestamp: November 03, 2023, 03:18:33 am
content: I do not have that specific application note. It is a bit of an odd number for an application note, which usually are ANxxxx. Here is a link to a PIC12C508 light dimmer by microchip:http://ww1.microchip.com/downloads/en/AppNotes/40171a.pdfIt is in collated references that Microchip occasionally puts together, and it might be similar. The 12C508 and 12F508 are similar, except the 12C508 is OTP, which you probably don't want to use.Do you need the code or the circuit? What language, MPLab ASM or C? One thing to be aware of is that the 12Fxx (and 16F5xx) series do not have interrupts; whereas,the 12F6xx and later 8-pin chips do.

author: Ian.M
author_rank: Super Contributor
timestamp: November 03, 2023, 03:54:54 am
content: That *IS* EN011202!Its on the Internet Archive Wayback Machine:Code:https://web.archive.org/web/20040511184907/http://www.microchip.com/stellent/idcplg?IdcService=SS_GET_PAGE&nodeId=1824&appnote=en011202Posted as code because this forum breaks wayback links due to the extra http://!

author: shakalnokturn
author_rank: Super Contributor
timestamp: November 03, 2023, 09:45:20 am
content: Thanks to both of you.I was looking for that application note because I remembered reading it back in the day.It seems that I was mislead by links in forums to the old filename on the Microchip website. Of course as on other corporate websites the file URLs have changed over the years.I wanted to look back at that document for their crude approach of zero cross detection, I have a small photovoltaic router project in mind that will probably use assembler on a PIC10F222 because I have some around and they should be good enough to get the job done.

author: jpanhalt
author_rank: Super Contributor
timestamp: November 03, 2023, 09:57:20 am
content: That should be a fun project. The 10F322 gives interrupt ability, but you don't have that. I also write Assembly and would love to see you post your results here.John

author: Ian.M
author_rank: Super Contributor
timestamp: November 03, 2023, 10:29:42 am
content: Don't expect EN011202 orAN521zero crossing detection to work well or at all on a more modern PIC, though if you get lucky it may work on some pins ...ReadTB3013to find out why, noting that more modern devices are even more sensitive to current through the lower protection diodes, then resign yourself to adding a BAT54S (or similar) dual series Schottky diode to your BOM to clamp the ZCD input and prevent *any* substrate charge injection, or at the very least providing a footprint to add such clamping later even if you believe your design uses a 'safe' digital only pin far enough away on the die from the oscillator(s), voltage reference and any other analog features, for when you get the nasty surprise of your oscillator frequency going way out of spec or your PIC locking up for lack of it!