| houkime | added. | 00:01 |
|---|---|---|
| Joerg-Neo900 | ta | 00:11 |
| houkime | Joerg-Neo900, on the display connector, pins 39-31 am i correct to assume that it is backlight LED array? | 16:50 |
| Joerg-Neo900 | sorry, I don't know off top of my head. Maybe refer to original N900 schematics | 16:51 |
| houkime | Joerg-Neo900, is it avalable even? | 16:52 |
| houkime | *available | 16:52 |
| Joerg-Neo900 | of course | 16:52 |
| Joerg-Neo900 | http://neo900.org/stuff/block-diagrams/neo900/neo900.html is a block diagram, you need to google for the schematics | 16:53 |
| houkime | fetched RX-51 chematics from plan9 | 16:56 |
| houkime | yep it is backlight | 16:57 |
| Joerg-Neo900 | houkime: please check docs/hw/Nokia_N900_RX-51_Schematics.pdf et al... in maemo.cloud-7.de/_hidden and NEVER EVER post the concatenated URL so spiders could start searching it! If this happens, the URL vanishes in no time | 17:00 |
| Joerg-Neo900 | you can search dirs up to docs/ | 17:01 |
| Joerg-Neo900 | all of this stuff is (or was) publicly available, but I collected it for convenience reasons | 17:11 |
| houkime | replacing D1902 (zener in backlight regulation) with BZX884 | 18:52 |
| houkime | (it needs to be able to regulate either on the 10.5v level or 21v level) | 18:53 |
| houkime | depending on serial or parallel connection of backlight LED rows | 18:53 |
| houkime | BZX884 series contains parts for both voltages with the same footprint | 18:54 |
| houkime | it is also new (2018) and small | 18:54 |
| houkime | previous zener there was misrated and too weak. | 18:55 |
| houkime | replaced | 19:41 |
| Joerg-Neo900 | >><houkime> BZX884 series contains parts for both voltages with the same footprint<< :thumbsup: | 19:52 |
| Joerg-Neo900 | >>too weak<< it only triggers a shutdown, doesn't regulate by itself | 19:53 |
| Joerg-Neo900 | actually which Zener? | 19:58 |
| Joerg-Neo900 | got it added post http://neo900.org/stuff/kicad/proto_v2/2016-11-20/ ? | 20:00 |
| Joerg-Neo900 | I'd really feel less nervous if I knew exactly what schematics you're working from | 20:01 |
| houkime | this one is from official neo900 schematics, D1902 is present on the master branch as far as i remember | 20:03 |
| Joerg-Neo900 | https://i.imgur.com/0zE7UIp.png latest in my local git branch | 20:03 |
| Joerg-Neo900 | master | 20:04 |
| houkime | interesting | 20:04 |
| Joerg-Neo900 | no idea what's going on | 20:04 |
| houkime | need to recheck | 20:04 |
| Joerg-Neo900 | don't get me wrong, probably a Zener is an excellent idea (if applied correctly frpm P1901G 31 to 29) but why don't I see it? | 20:08 |
| Joerg-Neo900 | ugh wait, not this way | 20:09 |
| Joerg-Neo900 | this sucks, the original design doesn't allow for a zener | 20:10 |
| Joerg-Neo900 | you'd need a 10k or somesuch (instead trace) from R1915 to R1906, then Zener to R1906 | 20:12 |
| Joerg-Neo900 | 1k | 20:12 |
| houkime | interesting. I rechecked. This realy isn't in master | 20:13 |
| houkime | hmmm... | 20:13 |
| Joerg-Neo900 | so Zener pulls up FB without using up full current meant for backlight# | 20:13 |
| houkime | Will need to investigate how this happened | 20:13 |
| Joerg-Neo900 | that's what eeshow is for | 20:14 |
| Joerg-Neo900 | just bisect while watching the index sheet until a change on sheet 19 is shown by yellow mark of sheet19 on index sheet | 20:18 |
| Joerg-Neo900 | alas it seems it's borked for me now | 20:19 |
| houkime | this is how itlooks on my end http://susepaste.org/view//47782775 | 20:19 |
| houkime | ok, will try to bisect | 20:19 |
| Joerg-Neo900 | zhere's a R1917 which I just "invented" :-D | 20:20 |
| houkime | it is actually how i found it in regulator datasheet as one of the applications so it wasn't looking suspicious for me. | 20:21 |
| Joerg-Neo900 | looks good but I have no idea who and when designed this | 20:21 |
| Joerg-Neo900 | DNP comment oon R1912 and 1914 missing | 20:23 |
| Joerg-Neo900 | aaa nope, all fine | 20:26 |
| Joerg-Neo900 | they are "[ serial]" | 20:26 |
| Joerg-Neo900 | bug: R1917 1k to allow Zener to pull ip FB | 20:28 |
| Joerg-Neo900 | check if that complies with FB impedance | 20:29 |
| Joerg-Neo900 | if needed, make it 100R | 20:29 |
| houkime | ok. | 20:32 |
| Joerg-Neo900 | rationale: when user operates device without display connected, avoid overvoltage from missing feedback to FB. But also avoid Zener and R1916 consuming the full power (10V * 40mA?) usually consumed by display backlight | 20:36 |
| Joerg-Neo900 | it's actually *possible* that Metacollin discussed this with me and added the Zener | 20:50 |
| Joerg-Neo900 | ...and I forgot | 20:50 |
| Joerg-Neo900 | houkime: did I already thank you for the great work? | 20:53 |
| Joerg-Neo900 | a pity it can't help the project anymore | 20:54 |
| houkime | i don't think the life of the project has anything to do with what you or me think about the current status. | 20:57 |
| houkime | it is opensource now completely. | 20:57 |
| houkime | people decide what to do with it | 20:57 |
| houkime | i make these changes now for people | 20:58 |
| houkime | in the end, after i am done with it, i can just eliminate N900 compatibility requirement, design a case in a freecad, replace display and retune tracks for new antennas and it will be good to go regardless of part sourcing. | 21:02 |
| houkime | forgot to correctly place a slide sensor on the UPPER... oops. | 21:56 |
| houkime | luckily a transform is already on hand | 21:56 |
| houkime | placed and locked | 22:33 |
| dos1 | houkime: still got issues with git repos? | 22:54 |
| houkime | dos1, no, it is ok. | 23:23 |
| houkime | dos1, checked right now | 23:24 |
| houkime | remote is not too verbose but clone does finish after a long while | 23:24 |
Generated by irclog2html.py 2.17.0 by Marius Gedminas - find it at https://mg.pov.lt/irclog2html/!
