ESR meter upgrades

[stj]

maybe i will manage to do some releases by the weekend!!
the build-rig is back together, i just need to back up the drives before i do anything else with it.

[Per Hansson]

Just saw this on the German forum that I had missed:

rnd D. schrieb:
> Hallo Karl-Heinz, ich habe einen 1500µF Elko, der vom Tester je nach
> Version als Diode mit großer Sperrkapazität angezeigt wird.

Hallo Bernd, angeschlossene Elkos machen bei der Detektion von Dioden
Probleme, da das Spannungsverhalten manchmal seltsam ist. Die Probleme
kommen daher, daß Dioden über das Spannungsverhalten bei angeschlossenem
470k und 680 Ohm Widerstand erkannt werden. Das Sperrverhalten wird
nicht untersucht, weil auch antiparallel geschaltete Dioden erkannt
werden sollen.
Bei Elkos läßt sich das Problem umgehen, wenn man diese im speziellen
Kondensator-Meßprogramm (1-||-3) untersucht. Wenn man nur Elkos
untersucht, ist auch das ESR-Programm (C+ESR@TP1:3) brauchbar. Hier ist
die Kapazitätsbestimmung nicht so genau, da mit sehr kleinen
Meßspannungen gearbeitet wird. Für Elkos sollte die erzielte Genauigkeit
aber ausreichen. Der Kapazitätsbereich ist auch etwas eingeschränkt
(2µF-50mF). Dafür ist dieses Programm aber für eine Messung in der
Schaltung (in circuit) brauchbar.

Here is the same function described from the PDF manual:

C+ESR@TP1:3 The additional function ”C+ESR@TP1:3” selects a stand-alone capacity measurement
with ESR (Equivalent Series Resistance) measurement at the test pins TP1 and
TP3. Capacities from 2µF up to 50mF can be measured. Because the measurement voltage is
only about 300mV , in most cases the capacitor can be measured ”in circuit” without previous
disassembling. If the POWER OFF option is selected in the Makefile, the count of measurements
is limited to 250, but can be started immediately again. The series of measurements can
be finished with a long key press.

Live and learn

[stj]

i knew about that - it's documented in the code.
it does not alter the fact that 90% of the time there will be something else in parallel with the cap that screws with the reading.

[turbochris]

I thought about using 2 cells but there's no off the shelf USB charge module available. The module I'm using seems like it's OK I used it on my DSO150 scope build. Will I have to recompile the firmware with a lower low battery threshold?

[stj]

yes, or it will switch off as soon as it tells you the voltage.
i wouldnt know about usb charge boards - i dont trust lithiums so i only charge them in the standalone charger.

[stj]

update
only GM328 for now - the build-box is in bits and RSYNC is doing it's thing.

btw, as usual there is some functions not activated by default - well they are now.
i had to drop down to 8x8 font to get everything to fit for now - until i can rip the contrast menu out again!

[Per Hansson]

As I said here I think the 8x8 font is better anyway so leave it in

https://www.badcaps.net/forum/showpo...&postcount=767

[stj]

the build box is now running - as a room heater!!!
so if anybody wants any custom builds - just ask.
tell me the hardware and anything "custom" needed, and i'll compile it.

[hal9008]

Please stj, when possible, post a recent version for "AY-AT". Thanks.

[stj]

not tested.

[turbochris]

if your room is still cold, please warm it up and compile one for me! AY-AT board, ST7735 display, 16 mhz and I need the low voltage cutoff set to a more li-po friendly value I guess 3.2 volts?

[stj]

o.k.

[eccerr0r]

Speaking of these AVRtesters, has the 16x2 LCD become deprecated or will they still work just fine with all the new features? (of course, no pretty artwork unlike on the graphic displays...)

[stj]

Originally Posted by eccerr0r

Speaking of these AVRtesters, has the 16x2 LCD become deprecated or will they still work just fine with all the new features? (of course, no pretty artwork unlike on the graphic displays...)

depends on the cpu
you really need an atmega328p

if you have an atmega8 / atmega168 then you dont have enough flash memory.
on the bright side - they all have the same pinout - so you can upgrade the chip.
make sure you get it from china though, or it will cost almost as much as a new tester.

[stj]

Originally Posted by turbochris

if your room is still cold, please warm it up and compile one for me! AY-AT board, ST7735 display, 16 mhz and I need the low voltage cutoff set to a more li-po friendly value I guess 3.2 volts?

i dont know, i'm pretty sure the cutoff is 3.6 for li-on

anyway - i made several - so no problem.

[vinceroger69]

Originally Posted by Per Hansson

Just saw this on the German forum that I had missed:


Here is the same function described from the PDF manual:

Live and learn

per hansson is additional function ”C+ESR@TP1:3” option enabled in your version of the firmware i have just put onto my tester thanks

[stj]

afaik it's always present if the menu is enabled.

[vinceroger69]

Originally Posted by stj

afaik it's always present if the menu is enabled.

Thanks stj as you know i have two of these testers so going too have your version on one and per hassons on the other.

[eccerr0r]

I would imagine the 16x2 LCD's would require less memory because they don't have any graphics to store! (?) Then again you can program bitmaps into them...

I also hear that the mega8 and mega168 lack features like adjustable vref and thus can't do as much as the mega328 anyway, so that stuff can be compiled out, saving some flash?

[stj]

so what chip do you have?