Contrast This function is available for display controllers, which can adjust the contrast level with
software. The value can be decreased by a very short key press or left turn with the rotary
encoder. A longer key press (>0.4s) or a right turn of the rotary encoder will increase the value.
The function will be finished and the selected value will be saved nonvolatile in the EEprom
memory by a very long key press (>1.3s).
Has anyone tried this (assumed to be) recent Chinese revision? They are calling it a 2016 EZM328 (GM328R) transistor tester.
http://www.ebay.com/itm/2016-EZM328-GM328R-transistor-tester-ESR-frequency-meter-square-wave-genera-/272165236396
I'm still skimming things (81 pages is a LOT ), but I'm genuinely curious if anyone has come up with a PC board that unifies all the options that are possible. Input protections, higher zener testing, support for ATmega 644 or 1284, etc? I saw a unit with built in protection quite a few pages back, but it used the text LCD, and I just like the graphic LCD too much!
Has anyone tried this (assumed to be) recent Chinese revision? They are calling it a 2016 EZM328 (GM328R) transistor tester.
http://www.ebay.com/itm/2016-EZM328-GM328R-transistor-tester-ESR-frequency-meter-square-wave-genera-/272165236396
It costs a little bit more, but the unit has a socketed DIP ATmega328, A rotary encoder/test button, graphic display, headers for frequency and flying test leads, the standard ZIF socket we've seen on most of these units, and claims to have a precision reference source. The listing says it's using "the 2016 version of the latest V1.12K software".
Has anyone tried this (assumed to be) recent Chinese revision? They are calling it a 2016 EZM328 (GM328R) transistor tester.
http://www.ebay.com/itm/2016-EZM328-GM328R-transistor-tester-ESR-frequency-meter-square-wave-genera-/272165236396
It costs a little bit more, but the unit has a socketed DIP ATmega328, A rotary encoder/test button, graphic display, headers for frequency and flying test leads, the standard ZIF socket we've seen on most of these units, and claims to have a precision reference source. The listing says it's using "the 2016 version of the latest V1.12K software".
if you don't mind a bit of soldering, i'd go for this one:
http://www.ebay.com/itm/M328-LCD-12864-DIY-Transistor-Tester-Kit-Diode-Triode-Capacitance-LCR-ESR-Meter-/161913228003?hash=item25b2c7cae3:g:pvwAAOSwf-VWZ~zL
This one does have a VRef, and 0.1% Rs - and flashing latest firmware is also possible, if you have some socket with ISP headers for the Atmega...
These devices remind me of a more advanced version of the transistor tester on my old DMM. It was a Radio Shack 22-174 and it had a three terminal transistor tester that did not require you to know the part or pinout, You just inserted the part any way, pressed the test button, and it told you if it was PNP or NPN, told you the pin configuration, and gave an hfe measurement. Obviously, not as advanced as this unit, as it only did those two types of transistors, but this was also made way back in the 1990s.
I bought this tester eBay auction: #http://www.ebay.com/itm/221961865013 and found it does a poor job at capacitance/inductance measurement, which is what brought me to this forum. Based on what I read, I believe this to be a LCR-T4 12864LCD unit with unversioned Chinese firmware, although it does not match precisely any tester photo I've seen on this thread. I hope to reflash with M- or K-firmware and solve my issues, and I think mega328_st7565_kit is the right branch, correct?
I am very disappointed because it does not recognize field effect transistors (tested: 2N3819 and MPF102) These are seen as bipolar NPN with a very high gain (between 100 000 and 510 000!)
The low value inductors (2.2 nH) appear as resistors (maybe normal ?)
The low value inductors (2.2 nH) appear as resistors (maybe normal ?)
[...]
I am very disappointed because it does not recognize field effect transistors (tested: 2N3819 and MPF102) These are seen as bipolar NPN with a very high gain (between 100 000 and 510 000!)
The low value inductors (2.2 nH) appear as resistors (maybe normal ?)
Do you have the same phenomena ?
What can I do ? change firmware ?
thanks for your advices
Gerard
[...]
If I rebuild code, how do I know that I have the build flags properly set? Although this looks like a standard design, can I irreversibly damage it with improper options selected? Could I reflash with my code+eeprom data to get back to where I started? I thought I read somewhere that code pulled from the tester is not usable due to locking. Since I did get something, would it not be valid?
[...]
A 25mm wire loop (single turn) has a 10nH inductance.
A 25mm wire loop (single turn) has a 10nH inductance.
It does?
Seems to be a slightly modified PCB of the T4 clone. For the k-firmware the best bet would be mega328_T3_T4_st7565 and for the m-firmware there's a display profile in the config.h file. The firmware you've downloaded from the clone looks fine. It got a lot of known strings So I'd guess, you could re-flash it.
I tried reflashing with 1.12k_r453 prebuilt by Tomas (https://www.mikrocontroller.net/topic/248078?goto=4120737#4105488) which turned the backlight on but nothing more. I was able to flash the code I originally extracted back and at least it works again.
CFLAGS += -DVOLUME_VALUE=50