ESR meter upgrades

[bc989]

Originally Posted by stj

can you double-check those pads, they use that to program them after assembly.

Looking at the schematic and comparing to different high-res T3/T4 on google image is making me think my clone got the RESET connection wrong.

I attach 2 better pics to show difference. The 2nd pic (mine) has a via that goes to pin 30 that other T3/T4 don't use.

Thinking I should cut and reroute it to the correct pin 29.

[stj]

there are a few bad points on that board.
i would replace the TL431 with an LM4040, and use a 3v3 regulator instead of the pair of diodes top-center.

[bc989]

Thanks, hope a stable 3v3 will stabilize the LCD and fix the flickering while testing.

Also got the rotary encoder (green color) why it needs so much force to push down compared to original button? Surely sore fingers after many component test. Are rotary encoder this hard to press?

[stj]

you dont want it geting pressed by accident.
and it's intended to have a knob fitted.

[vinceroger69]

stj is this kit ok in your opinion
http://www.ebay.co.uk/itm/3318737413...%3AMEBIDX%3AIT

[stj]

looks about the same as the banggood one, cant tell if either have protection diodes though.
but the price is very good.

i still cant understand why the chinese arent using 16MHz crystals yet.

[vinceroger69]

cheers i will order one its in a kit form so will give me something too do can these be upgraded?

[bc989]

stj, finally got to test your 'T4 ESR tester (testing v1).zip' from page 6. Its not compatible on mine, just a blank screen.

The ones from the russian site are not working too.

Only after trying some more on https://github.com/svn2github/transistortester did I find 3 that displayed something except its all flipped, mirror vertically and horizontally in all ways except the right way. The one that is still readable upside down is "mega328_st7565".

Guess I need to play with the Makefile and compile it myself.

[stj]

blank screen could be the contrast setting - i had that issue when i started doing this stuff.

about upgrading,
the biggest upgrade is probably the crystal.
a 16MHz crystal means you can also test crystals and resonators upto about 12MHz

other than that,
replacing the 1117 / 7805 regulator with an mcp1702 lets you run the living hell out of the battery until it's only got about 5.6v left in it!!

replacing a zener diode or 431 voltage reference with an lm4040 will increase accuracy.

the other thing i'm working on - a relay that switches a cap across the socket for testing small inductors.
sounds simple, but the cap must be stable - mine is 2%, and the relay should have a magnetic shield or it will mess with the inductor being tested.

[vinceroger69]

so when i get mine i will take measurements of the crystal and voltage regulator and order upgrades do i need to programme the board for the crystal to work correctly?

[GoNz0]

Originally Posted by stj

blank screen could be the contrast setting - i had that issue when i started doing this stuff.

about upgrading,
the biggest upgrade is probably the crystal.
a 16MHz crystal means you can also test crystals and resonators upto about 12MHz

other than that,
replacing the 1117 / 7805 regulator with an mcp1702 lets you run the living hell out of the battery until it's only got about 5.6v left in it!!

replacing a zener diode or 431 voltage reference with an lm4040 will increase accuracy.

the other thing i'm working on - a relay that switches a cap across the socket for testing small inductors.
sounds simple, but the cap must be stable - mine is 2%, and the relay should have a magnetic shield or it will mess with the inductor being tested.

Will I be able to do all this with the banggood kit?

Thanks.

[stj]

to both of you - yes.
the normal crystal is 8MHz, you just swap it out.

same with the regulator and reference - although you need to check the pinouts to get the replacement the right way around.

if you change the crystal, you need to change the software.

[bc989]

Ok for my unknown nameless Mtester clone, I got the display back by removing from your Makefile, just this one line:

CFLAGS += -DSTRIP_GRID_BOARD

also to stop the compiler from choking, had to change function_menu.c line 133 to:

uint8_t function_menu() {

[stj]

strange, you talking about a compiler warning or a compiler error?

[bc989]

This is what it showed, pointing to function_menu.c, so I simply changed it.

$ make
avr-gcc  -Wall -DWITH_MENU -DWITH_CONTRAST -DWITH_ROTARY_SWITCH=2 -DCHANGE_ROTARY_DIRECTION -DFOUR_LINE_LCD -DLCD_ST7565_H_OFFSET=0 -DVOLUME_VALUE=48 -DFONT_7X12 -DICON_TYPE=3 -DBIG_TP -DSTRIP_GRID_BOARD -DWITH_SELFTEST -DAUTO_CAL -DWITH_UJT -DWITH_PUT -DWITH_AUTO_REF -DREF_C_KORR=12 -DREF_L_KORR=40 -DC_H_KORR=0 -DWITH_UART -DRMETER_WITH_L -DCAP_EMPTY_LEVEL=4 -DAUTOSCALE_ADC -DREF_R_KORR=3 -DESR_ZERO=20 -DNO_AREF_CAP -DUSE_EEPROM -DPULLUP_DISABLE -DANZ_MESS=25 -DPOWER_OFF -DBAT_CHECK -DBAT_OUT=3 -DBAT_POOR=6400 -DBAT_NUMERATOR=133 -DBAT_DENOMINATOR=33 -mcall-prologues -DLCD_ST_TYPE=7565 -DLCD_ST7565_RESISTOR_RATIO=4 -DF_CPU=8000000UL -DMHZ_CPU=8 -mmcu=atmega328p -gdwarf-2 -std=gnu99 -Os -funsigned-char -funsigned-bitfields -fpack-struct -fshort-enums -MD -MP -MT function_menu.o -MF dep/function_menu.o.d  -DSamplingADC -c  ../function_menu.c
../function_menu.c:133:6: error: conflicting types for 'function_menu'
 void function_menu() {
      ^
In file included from ../Transistortester.h:12:0,
                 from ../function_menu.c:5:
../tt_function.h:49:9: note: previous declaration of 'function_menu' was here
 uint8_t function_menu();   // menu for selecting extra function
         ^
make: *** [../finish.mk:13: function_menu.o] Error 1

Fyi I'm using Atmel toolchain.

[stj]

what gcc version?

[bc989]

avr-gcc.exe (AVR_8_bit_GNU_Toolchain_3.5.2_1680) 4.9.2

[stj]

hmm. i'm using 4.8.1

you need to be carefull, the newer versions create larger files.
upload your makefile.

[bc989]

Yes its bigger by a bit.

ok Makefile attached with that 1 line remarked out and the hex/eep in case anyone with the same model as mine wants to try.

[stj]

is the contrast right, or do you have to fine-tune it from the menu?