VDI-RODERICO

[roderico]

128х64 ks0108.... PCB has already mocked up [ATTACH]49310[/ATTACH]

SWL, if you have not already built your new pcb maybe it would be better to wait for the 2.5V voltage reference tests since it will replace R7 and R8. I don't have yet the MCP1525 or LM336 but maybe someone else could test it sooner...

[SWL]

Wow! Thank you very much,waltr! You saved me ... I will order the details ... Thanks again!

[waltr]

128х64 ks0108.... PCB has already mocked up

Ok, here is the Hex. Only code that changed is a few conditionals for 18F26K22 instead of 18F25K22.
Hope this helps.

[roderico]

Roderico, Here is the Scope plot with the Furnace running. Also the X-Y plot when furnace is not running.

neither was the mains nor was it noise , X and Y have ~ the same amplitude, ~10Hz and are ~90 phase-shifted, so a Lissajous curve (circle for 90) produced by the furnace

[SWL]

128х64 ks0108.... PCB has already mocked up

[waltr]

Oh my God.. ... it's too hard for me ... Have to study...

SWL,
Post which display you are using from Roderico's list and I can build the Hex file and post it for you.

It is mind bending to do this first time but very easy later.

[waltr]

Roderico, Here is the Scope plot with the Furnace running. Also the X-Y plot when furnace is not running.

[roderico]

yes, the answer is exactly waltr's post. I've been looking for other alternatives to the LM336 and MCP1525 could be a good alternative, for a 3.3V I couldn't find any...

[SWL]

Oh my God.. ... it's too hard for me ... Have to study...

[waltr]

Hello roderico! I have a question. I can’t find Pic18f25k22. Can I use Pic18f26k22 instead of 25? I have the opportunity to buy it. Thank you!

I can answer that.
The difference between them is the F26K22 has twice as much memory so yes, the PIC18F26K22 will work. You will need to start with Roderico's Source code and create a project in MPLAB X for the 26K22 then build to produce the Hex file.

[SWL]

Hello roderico! I have a question. I can’t find Pic18f25k22. Can I use Pic18f26k22 instead of 25? I have the opportunity to buy it. Thank you!

[waltr]

Ok. I'll do a Scope View photo with the AC MAINS interference tonight.

I haven't gotten to reworking the code or hardware for internal Vref, etc yet. I would like to get the ADC offset flicker values measured from a quiet location first.
I plan to get out Sunday since prediction is 39F (4C) and sunny so will be a nice day. Saturday is predicted snow and rain.

[roderico]

This clarifies very well the issue but I would like to see if possible the scope view to understand better how the circle is generated I guess they would be random values. As there is no much improvement using the internal voltage reference the other option was to test a 2.5V voltage reference for the ADC offset (both would be better), I took an example from the LM336 (https://www.ti.com/lit/ds/symlink/lm336-2.5-n.pdf)

[waltr]

this looks pure noise to me maybe because you are using very long unshielded wires before and after the MCP602 (more EMI/RFI), could you also post a picture of the scope view for the last picture (the one with a big circle) to see if this comes from the long wires or from the coil? You might also increase the trigger level e.g. to 15mV or 20mV (losing some depth)

It is coming into the Coil not the wires. As I pointed out this is completely due to EM interference in my work shop when the furnace and circulating pumps are running.
I was simply pointing out that EM interference does exist and the need to ensure one does not try troubleshooting non-existant issues and the need to test away from AC Mains and EM interference. In my workshop when none of the heating equipment is running the detector output is quiet and the sensitivity as well as the X-Y plot is good.

Further, when first building the TGSL it was difficult to determine if the circuit had a issue or if it is EM interference. Many people on the forum building detectors have issues with low sensitivity and excessive noise due to EM in their workshops. The VDI X-Y display is very helpful to 'see' what might be going on. On the X-Y plot a Circle is AC MAINS interference. This makes the VDI graphic display more useful than simply helping ID a target in the field.

The photos I posted are only to show construction.

[roderico]

this looks pure noise to me maybe because you are using very long unshielded wires before and after the MCP602 (more EMI/RFI), could you also post a picture of the scope view for the last picture (the one with a big circle) to see if this comes from the long wires or from the coil? You might also increase the trigger level e.g. to 15mV or 20mV (losing some depth)