'KROT2-XM' (mole), new project Xmega32

[Tepco]

In case you still get same problem with new chip (or try this even before it arrive) try few more things. First, short 10uH inductor and see what happens. Just in case, maybe self-resonant at some undesired frequency, or too high resistance, or something else wrong with it... Then, set scope to highest sensitivity, 2 or 5mV\div, AC coupled, and check for noise present, coinciding with detector response, 3.3V line (noisy or faulty LDO), junction of R8\R7\C14, (leaky C14, noisy resistors etc), preamp output... With RX input shorted and all adjustments done, detector must be absolutely quiet.

[Geo]

In case you still get same problem with new chip (or try this even before it arrive) try few more things. First, short 10uH inductor and see what happens. Just in case, maybe self-resonant at some undesired frequency, or too high resistance, or something else wrong with it... Then, set scope to highest sensitivity, 2 or 5mV\div, AC coupled, and check for noise present, coinciding with detector response, 3.3V line (noisy or faulty LDO), junction of R8\R7\C14, (leaky C14, noisy resistors etc), preamp output... With RX input shorted and all adjustments done, detector must be absolutely quiet.

I"ll try today to make the tests. What do you mean with LDO??
When i received pcb from WM6 it had not the erratic signals but had bad sensitivity because MCP601 was faulty. I don't know what happened later and i have so many problems. Maybe any short at pins of D3 to destroyed it.
Btw... with D1, D2 and LCD disconnected detector has erratic signals. The same with D1, D2 and D4 disconnected.

[ANDREW K2]

Here's the video from Geo:

[ATTACH]27989[/ATTACH]

What are you supply devices? Check the capacitors C14 and C28.
And luchshe see (and show) oscilloscope pin 44 D3!
Still try to make the current TX=0, mode "Power_TX".

[Geo]

Hi ANdrew.
I try to stop the erratic signals.
You hear at video that there are a lot of erratic (fault) signals. All the time you hear beep...beep... and nothing else.
I wait for a new uC so to replace it.

[ANDREW K2]

Why do you think we need to change XMEGA? What do you have 44 pins? What voltage shows K2? All this must be done without coil!
I already wrote to you, try to tear pin 44 from R13 and connect to pin 1 ...

[Geo]

What is K2???. I can't see any symbol K2. Today i changed the filter from F3 to F1. At dynamic mode the erratic signal stoped. At static mode there was some signals but less than previous time. Tommorrow i will look it better.
Who is the "job" of filters F1, F2 and F3???

Also i ckecked vcc at pin 40, pin44 and gnd with oscilloscope. There is a noise (near to 2us) 5 ... 10mv. I am not sure if this rate is small or large.

Regards

[WM6]

What is K2???.

Probably KROT2.

AMS1117 3.3V voltage regulator is used. It was about 3.27V at regulator output.

[Geo]

If so .. yes voltage is 3.27 ...3.28V.

[SimonS]

Today I have some free time so I finish PCB. Now the hard think called the coil

[bernte_one]

looks good

[reiv]

Hey and what about this unstable erratic noisess only Geo has it ? Is this md stable outdoor?
Regards

[WM6]

Today I have some free time so I finish PCB. Now the hard think called the coil

Good work SimonS, wish you all success with coil.

[SimonS]

Thanks!
Today I do wire work and put PCB in box. Look good for now. I'm waiting for coil shell to finish this project.
I have one question. Where to connect shield of RX,TX cable? To GND or AGND?

[WM6]

Thanks!
Today I do wire work and put PCB in box. Look good for now. I'm waiting for coil shell to finish this project.
I have one question. Where to connect shield of RX,TX cable? To GND or AGND?

Do you have cable with separate shielded RX and TX wires? Can you post photo of your cable (de-isolated at the end, to see structure)?

[SimonS]

sure. Here are photos.
Cable to connector are shield. Shield are connected to GND (on TX on GND, on RX to AGND)
Now problem where connected main cable and coil shell ? I think it is better to GND???