$20 LCR ESR Transistor checker project

[kelchm]

I just finished putting together an AY-AT kit with a color lcd. It seems to work if I hold down the encoder momentary switch, but turns off immediately when letting go of the switch.

Any ideas where to start with troubleshooting?

[madires]

Re-asking my question, hoping someone (Markus? ) knows the answer... how bad would it be to use 750 Ohm instead of 680 and 499K Ohm instead of 470k?

Basically you can use different values as long as you update the constants for the probe resistors in the source. But with different values you also change the max. test current:
for 680 Ohms: I = 5 V / (680 Ohms + 40 Ohms) = 6.95 mA
for 750 Ohms: I = 5 V / (750 Ohms + 40 Ohms) = 6.33 mA
(the 40 Ohms are the internal resistance of the pin drivers)

This is about 10% less. The lower test current will have an impact on several measurements, like inductance for example.

[madires]

I just finished putting together an AY-AT kit with a color lcd. It seems to work if I hold down the encoder momentary switch, but turns off immediately when letting go of the switch.

Any ideas where to start with troubleshooting?

Please check the transistor which is controlled by the MCU to keep the power supply running.

[robca]

Basically you can use different values as long as you update the constants for the probe resistors in the source. But with different values you also change the max. test current:
for 680 Ohms: I = 5 V / (680 Ohms + 40 Ohms) = 6.95 mA
for 750 Ohms: I = 5 V / (750 Ohms + 40 Ohms) = 6.33 mA
(the 40 Ohms are the internal resistance of the pin drivers)

This is about 10% less. The lower test current will have an impact on several measurements, like inductance for example.

Awesome answer, thanks so much!

Will need to decide what to do, if trying to match 3 1% resistors to within 0.1%, change the settings or bet the right resistors... but at least I know for sure now

[kelchm]

Please check the transistor which is controlled by the MCU to keep the power supply running.

Excuse my ignorance, but which transistor is that and how do I check if it is functioning correctly?

I see the TL431A, but that looks to be a voltage regulator. I've attached a photo of my board.

[GBowes]

I would have to check a schematic to answer which transistor, BUT my bet is on the fact that you left out the LED.
The LED is needed to supply the collector of the transistor held on by PD7.
I think if you install it, your problem should be solved.

Graham

Excuse my ignorance, but which transistor is that and how do I check if it is functioning correctly?

I see the TL431A, but that looks to be a voltage regulator. I've attached a photo of my board.

[kelchm]

I would have to check a schematic to answer which transistor, BUT my bet is on the fact that you left out the LED.
The LED is needed to supply the collector of the transistor held on by PD7.
I think if you install it, your problem should be solved.

Graham

Excuse my ignorance, but which transistor is that and how do I check if it is functioning correctly?

I see the TL431A, but that looks to be a voltage regulator. I've attached a photo of my board.

That was indeed the issue. I somehow cooked my first led but was able to dig up another red led from my parts drawer.  Working great now.

[crimsonknight3]

I have spent a few hours looking through this thread but haven't found anything (well someone asked a similar question but it was overlooked)

I got my t4 variant today (using the mega 328p + 8mhz) and immediately came back here and got a brain ache to figure out exactly which firmware to use, before using my Arduino UNO as isp to flash the device. cmd prompt shows that the device erases, flashes, then read okay, however, there seems to be zero change to the firmware. No menu (I have not rotary encoder to hand so just wanted to test the firmware while waiting for one) I checked the makefile and edited out the rotary encoder part, changed the font slightly and slowly checked every single parameter to make sure it was all in line with everything I know about the T4 and specifically the variant I have.

The only (slight?) clue I have is that avrdude reports that there is an invalid signature, and so I had to force it. However, I am 100% sure without a shadow of a doubt that the connections between the Arduino + the device are 100% correct. I originally tried using 3.3v on the Arduino however after looking closely at a post WAY back in this thread, I found that person to be using their UNO's 5v, so I tried that also and still "installs" fine but makes no difference to the device.

[Willem52]

Did you flash both the Programflash (.hex) and EEprom file (.eep)
and did you flash the correct fuse settings?

[crimsonknight3]

Did you flash both the Programflash (.hex) and EEprom file (.eep)
and did you flash the correct fuse settings?

I forgot the fuse settings >.< What are they for the t3/4 (the yellow board)?

[Willem52]

The fuses:
lfuse: 0xf7   hfuse: 0xd9   efuse: 0x04

[madires]

I'm working on the IR decoder/sender tools and added a few more protocols to the sender and some optional ones to the decoder. The optional protocols are less common and can be activated by a compile time option:
  - IR60 (SDA2008/MC14497)
  - Matsushita (Panasonic MN6014, C5D6 / 11 bits)
  - NEC µPD1986C
  - RECS80 (standard & extended)
  - Sanyo (LC7461)
  - Thomson

Any suggestions for additional protocols?

[stj]

how are you doing on memory?

the K firmware pretty much cant go any further on common hardware because the flash is full!

[madires]

The firmware size depends on the features enabled and the display (& font). With all basic features, a ST7565 and the IR decoder plus optional protocols it's about 27kB. If you want to have all features you would need an ATmega644.

[kelchm]

Basically you can use different values as long as you update the constants for the probe resistors in the source.

What are the names of those constants? I took a quick look but did not see them.

[The Soulman]

I'm working on the IR decoder/sender tools and added a few more protocols to the sender and some optional ones to the decoder. The optional protocols are less common and can be activated by a compile time option:
  - IR60 (SDA2008/MC14497)
  - Matsushita (Panasonic MN6014, C5D6 / 11 bits)
  - NEC µPD1986C
  - RECS80 (standard & extended)
  - Sanyo (LC7461)
  - Thomson

Any suggestions for additional protocols?

Is it possible to a add the protocol for the fs9922 DMM chip?
This is a widely used chip and comes in a 4000 count "DMM3" and 6000 count "DMM4" variant, both use the same serial protocol.
Would be nice to be able to use it as a second display for my dmm's. (feeding it from a wireless link) 
Attached Linked is the datasheet describing the protocol (from page 30).

If you implement this, don't bother with the bar graph it's useless at 3 updates per second.

http://www.ic-fortune.com/upload/Download/FS9922-DMM4-DS-13_EN.pdf

[Lenny]

Select "show values" in the main menu to display the adjustment values and check if Vcc has changed. There's no dedicated indication that the external reference is used. Have you enabled HW_REF25 in config.h?

I have just come to it now.
The menu shows a value of 1085mV as Vcc. Can that be correct?

 I have not checked it before installing the LM4040. 

[madires]

Basically you can use different values as long as you update the constants for the probe resistors in the source.

What are the names of those constants? I took a quick look but did not see them.

k-firmware: R_L_VAL & R_H_VAL (autoconf.h)
m-firmware: R_LOW & R_HIGH (config.h)

[madires]

Is it possible to a add the protocol for the fs9922 DMM chip?
This is a widely used chip and comes in a 4000 count "DMM3" and 6000 count "DMM4" variant, both use the same serial protocol.
Would be nice to be able to use it as a second display for my dmm's. (feeding it from a wireless link) 
Attached Linked is the datasheet describing the protocol (from page 30).

If you implement this, don't bother with the bar graph it's useless at 3 updates per second.

http://www.ic-fortune.com/upload/Download/FS9922-DMM4-DS-13_EN.pdf

It's a RS232 TX flashed by an IR LED. An IR receiver module will have difficulties to pick that up, because it expects a modulated signal with a carrier frequency in a specific range. So we would need a custom receiver module for flashed IR.

[madires]

I have just come to it now.
The menu shows a value of 1085mV as Vcc. Can that be correct?

 I have not checked it before installing the LM4040. 

1085mV would be Vref (the internal bandgap reference).

[The Soulman]

Is it possible to a add the protocol for the fs9922 DMM chip?
This is a widely used chip and comes in a 4000 count "DMM3" and 6000 count "DMM4" variant, both use the same serial protocol.
Would be nice to be able to use it as a second display for my dmm's. (feeding it from a wireless link) 
Attached Linked is the datasheet describing the protocol (from page 30).

If you implement this, don't bother with the bar graph it's useless at 3 updates per second.

http://www.ic-fortune.com/upload/Download/FS9922-DMM4-DS-13_EN.pdf

It's a RS232 TX flashed by an IR LED. An IR receiver module will have difficulties to pick that up, because it expects a modulated signal with a carrier frequency in a specific range. So we would need a custom receiver module for flashed IR.

Not all meters with this chip have ir output, some have Bluetooth or wifi others none at all, The hardware interface should be implemented by the hobbyist's suited to his personal needs.
I was thinking to use the frequency counter pin as the input?

[perieanuo]

Is it possible to a add the protocol for the fs9922 DMM chip?
This is a widely used chip and comes in a 4000 count "DMM3" and 6000 count "DMM4" variant, both use the same serial protocol.
Would be nice to be able to use it as a second display for my dmm's. (feeding it from a wireless link) 
Attached Linked is the datasheet describing the protocol (from page 30).

If you implement this, don't bother with the bar graph it's useless at 3 updates per second.

http://www.ic-fortune.com/upload/Download/FS9922-DMM4-DS-13_EN.pdf

It's a RS232 TX flashed by an IR LED. An IR receiver module will have difficulties to pick that up, because it expects a modulated signal with a carrier frequency in a specific range. So we would need a custom receiver module for flashed IR.

Not all meters with this chip have ir output, some have Bluetooth or wifi others none at all, The hardware interface should be implemented by the hobbyist's suited to his personal needs.
I was thinking to use the frequency counter pin as the input?

For me next step is adapt Bluetooth and wifi options to detect and send remote signals like harmony hubs. Deviate maybe to a true universal remote branch but all for 50 euros max. Logitech sells a good solution over 160.anyway IR is dead long live BT

Envoyé de mon HUAWEI NXT-L29 en utilisant Tapatalk

[Fumio]

hello: I know this is much, much later than your post but in the event it may help someone else, I offer this information. I had same problem as you push rotary switch and flicker than nothing. My solution: transistor t103  an S9014 located just below the red led on the board was not conducting to ground. Replaced and all was well. To check this it is possible to run ground from negative side of red led to ground. If it is t103 it should work.
Regards Fumio

[Argiros]

I bought recently the GM328B,  with the smd circuit it is new with a color screen . The board named Geek Teches and has in the back of the screen an sd card slot!. Strange but I think it is not used at all for the moment. I believe that the quality is very good, but I didn't check the measurements so far but the menu is missing many things and the font colors are AWFUL small and difficult to see red in Blue background! Thats why I tried to program it.Also I think that the rotary models are far better! and easier to use.

I thought it was better than GM328 but not! I tried to program it with a pickit2 but I brick it. And now pickit cant see it at all and the device showing a white screen when power is on.
Can anyone know how I can reset it ? I tried pushing the 1st btn and powering it on waitting nothing. Also the 2nd button and both nothing. The 328P chip is a small smd soldered in the circuit and it is difficult to access it straight.

Also what firmware is compatible for this device ?
How we can delete all the eprom and data from this chip ?

[madires]

The GM328B's display seems to to be a ST7735. The precompiled version of the k-firmware for the GM328 (mega328_GM328) won't work obviously. So you would have to reverse engineer the pinout and configure the firmware accordingly. You can use the k or m-firmware.