felezjoo PI(the best pulse induction metal detector that I made until now)

[basellafe]

this pcb is not the oregenal one try to acheve deffrence with the oregenal one and test lines from a short secret if not the problem will be from prgraming or fuses you should hear a peeep when turn on

[chuubaba]

THE PROBLEM WITH MY CIRCUIT IS THAT THE VOLTAGE AT HIGHLIGHTED POINTS WAS GOOD PRIOR TO INSTALLATION OF ATMEGA AND LCD BUT WENT DEFICIENT AFTER ATTACHMENT. TRIED REMOVING LCD BUT STILL NO RELIEF. I DOUBT PROBLEM WITH LCD AND SUSPECT ATMEGA PROGRAMING AS I HAVE CHANGED THE IC THREE TIMES WITH SAME RESULT.

well I would test the LCD.......

[6666]

THANK YOU 6666. I WAS THINKING ABOUT THIS EVER SINCE I REACHED 100 POSTS MARK AND GOT BRANDED AS SENIOR MEMBER WHEREAS AS A MATTER OF FACT I DON'T KNOW HOW TO READ A SCHEMATIC. ANYWAY CAN YOU HELP US HERE WITH FELEZJOO. I HAVE REMOVED THE LCD FROM MY CIRCUIT BUT STILL NO IMPROVEMENT IN VOLTAGE.

well I would test the LCD, its easy, did you hardwire the lcd or is it pluggable ?
you can test the led on pins 15/16
connect 5 volt negative which is ground to pin 16
connect a 1 K resistor between 15 and +5 volts that should light the led.
now there is a simple test to get a line of squares.
connect ground to pin 1
connect +5 volt to pin 2
connect a 5-10K pot between ground and +5volts and the wiper to pin 3
this adjusts the contrast of the LCD , turn it, you should see a line of squares if working .
w

[chuubaba]

DEAR GLOWIAN I HAVE TRIED BY REMOVING THE LCD FROM CIRCUIT BUT STILL THE VOLTAGES ARE DEFICIENT. PLEASE TELL ME VOLTAGE OF ALL YOUR RADIAL CAPACITORS whether 16V OR 25V?

Chuubaba pin 2 LCD(orange circle)=VCC (power) of Atmega need to be close to 5V.
My PCB 4,982V if 12V supply try to put only Atmega no lcd my detector work normal for me without lcd.

[chuubaba]

THANK YOU 6666. I WAS THINKING ABOUT THIS EVER SINCE I REACHED 100 POSTS MARK AND GOT BRANDED AS SENIOR MEMBER WHEREAS AS A MATTER OF FACT I DON'T KNOW HOW TO READ A SCHEMATIC. ANYWAY CAN YOU HELP US HERE WITH FELEZJOO. I HAVE REMOVED THE LCD FROM MY CIRCUIT BUT STILL NO IMPROVEMENT IN VOLTAGE.

FYI the word GURU is nothing more than a incremented word purely based on the number of posts you make, it in no way indicates the level of expertise.

[6666]

TODAY I ATTACHED 16x2 LCD TO felezjoo PCB BUT IT DID NOT TURN ON. GIVING IT 12V DC FROM POWER SUPPLY, NO COMPONENTS HEATING UP OR ANYTHING. GURUS HELP ME SORT WHAT'S WRONG WITH IT. I HAVE MULTIMETER AND OSCILLOSCOPE TO TEST.

FYI the word GURU is nothing more than a incremented word purely based on the number of posts you make, it in no way indicates the level of expertise.

[chuubaba]

THANK YOU GLOWIAN. LET ME TRY TO REMOVE THE LCD AND SEE IF THERE IS A IMPROVEMENT IN VOLTAGE...

Chuubaba pin 2 LCD(orange circle)=VCC (power) of Atmega need to be close to 5V.
My PCB 4,982V if 12V supply try to put only Atmega no lcd my detector work normal for me without lcd.

[glowian]

Chuubaba pin 2 LCD(orange circle)=VCC (power) of Atmega need to be close to 5V.
My PCB 4,982V if 12V supply try to put only Atmega no lcd my detector work normal for me without lcd.

[chuubaba]

I HAVE USED YOUR PCB DIAGRAM TO MARK THE READING POINTS AND VOLTAGES . PLEASE NOTE THAT THESE READINGS WERE TAKEN WITHOUT INSTALLATION OF ATMEGA AND LCD USING 12V DC SUPPLY. IT IS AFTER I FIT ATMEGA AND LCD THAT THE VOLTAGE DROPPED SIGNIFICANTLY LOW AS FOLLOWS. BLUE CIRCLE = 3.5V. YELLOW CIRCLE = 1.5V. ORANGE CIRCLE = 1.32V. BOTH THE SCREEN AND SPEAKER REMAINED SILENT. NOW I RAISED THE VOLTAGE TO 30V AND FOLLOWING WERE THE READINGS; BLUE CIRCLE = 11.9V. YELLOW CIRCLE = 6.7V. ORANGE CIRCLE = 1.32V. BOTH THE SCREEN AND SPEAKER REMAINED SILENT. NO HEATING OF ANY COMPONENT.

Thank you very much. This will help me and will diagnose faults according to the voltage, the conductivity obtained or the signal to the oscilloscope on certain points of the circuit.

I do not know if it comes from a bad solder or a faulty component.

[gandolfi]

@gandlofi my expert help was taking voltage readings throughout the building of felezjoo and claimed it a success. I will get the voltage readings from him and map them on the PCB layout same way as you did....

Thank you very much. This will help me and will diagnose faults according to the voltage, the conductivity obtained or the signal to the oscilloscope on certain points of the circuit.

I do not know if it comes from a bad solder or a faulty component.

[chuubaba]

@gandlofi my expert help was taking voltage readings throughout the building of felezjoo and claimed it a success. I will get the voltage readings from him and map them on the PCB layout same way as you did....

[gandolfi]

i have the same problem

My detector worked well. I wanted to insert the detector in a box and I had to do a wrong manipulation. My screen does not work anymore (so I'm blind) and i bought a new. I have no sound at boot time.
I feed it in 19V.

- I have 5V between the terminal of the resistance 10k (next to pin 1 of the LCD) and the ground. pparently is the good value. I put a picture attached
- The 7805 is very hot.
- Are there points to test on the circuit (volt, impedance, oscilloscope) to check that we have not grilled or desoldered a component?

Thanks for your help

[chuubaba]

applied 18V from two 9V batteries but noting on lcd or speaker. Maybe there is some testing with multimeter or like...

[chuubaba]

I will power it with two 9V batteries and let you know immediately

These need 18volts as per previous posts preferable from high drain batteries not noisy psu.

[qute1]

These need 18volts as per previous posts preferable from high drain batteries not noisy psu.