VDI-RODERICO

[roderico]

I would suggest you first redo the circuit design... what improvements would you expect to have with PIC24 vs PIC18 in the vdi?

[scrungy_doolittle]

Just thought I'd ask.
I'm considering a 28 pin PIC24FJ64GA series probably the 202 since it has DMA, a 12 bit adc and 3 built in comparitors. 28 pins matches the number on the schematic, though the GA204 would be a better choice for actually using to build a fully computerized detector. And Yes, I know that either one of these are overkill for a simple VDI, but the fact remains that I'm more comfortable with a 16 bit part than an 8 bit one.

[roderico]

probably it would not work well with my settings, it would be easier for you to create a new project in MPLABX, select your pic, the compiler, simulator and then add the files to your project: _18f252.*, eeprom.*, fpu.*, mcu.* and the files in the lcd directory if you are going to use an LCD display or in the glcd for a GLCD. You would also need to set the pins manually in the files _18f252.* as the mcu's are not pin compatible and since pic24 is 16bit you would need to do some work to adapt the drivers (e.g. ks0108 ) and the peripherals (e.g adc, eeprom, ...)

[scrungy_doolittle]

Would you mind doing a package operation in the MPLAB X ide and sending it to me?
Did you use MCC to define the pins?

[roderico]

since the display menu is already full that new feature should go into a new tab alone (no good) or to an existing one (not very good IMO) so this might not be in version 2.1, however you can have it for testing e.g. in the main menu...

[kroman01]

I did not have much time for testing, although I see that soft 2.1 works well, good work, there are new features or there will be a problem with adding to the MENU the battery voltage measurement on or off when no indication

[SWL]

Ок...

[roderico]

this avoids different saturation levels for channels X and Y after the MCP602, it was found by kroman01 after the first version of the pcb (2.0) but the pcb was never updated only the schematics, in any case the firmware should work well in both versions 2.0 and 2.1 (in version 2.0 you would have an earlier clipping in channel Y when the op-amp is in saturation)...

[SWL]

Hello! The circuit and the pcb are different. Have you changed the scheme? Thank!

[roderico]

you might also need to change more files e.g. see eeprom.c, eeprom.h and mcu.h and the GLCD/LCD drivers since they are 8bit...

[roderico]

did you correct this
strcpy(name, "cooper "); should be "copper" in vdi.c

in these tests the names were removed because there is no enough space in PIC16F886 and they are misleading

Thanks for the code. I'm going to try porting it to a PIC24fj series part, since that is what I use in practically everything these days.

have a look at these two files: _18f25k22.h and _18f25k22.c these are the only files you would need to adapt to make it work...

[scrungy_doolittle]

did you correct this
strcpy(name, "cooper "); should be "copper" in vdi.c

Thanks for the code. I'm going to try porting it to a PIC24fj series part, since that is what I use in practically everything these days.

[roderico]

I updated the old THT version of the pcb reorganizing some of the components and I have changed the values of C1, C2, R3, R4 and the like to more common values for testing. Larger values of RT2 and R9 more similar to the original IDX schematic also work well, e.g. 10K (RT2) and 22K (R9).

- R11 needs to be chosen to limit the current to the backlight e.g. 8-10mA
- R7 and R8 are 1%
- C12, C13 and crystal Y1 are not necessary for PIC18F25K22 and PIC16F886
- for a LCD display short R15, pins CS1, CS2, RST and VEE are not used

[roderico]

this test version fixes a bug in the mean vdi (different index ranges), changes max(x,y) by the maximum extracted from the histogram and highlight the vdi value when the uncertainty is less than a given value e.g. 10 degrees (it can be disabled by setting the uncertainty to 0 degrees, i.e. all values are considered good measurements which is not very realistic)...

[roderico]

I merged beta1&2 in beta3 for testing, now it is possible to select how the vdi is extracted, i.e. as max(x,y) equivalent to v2.0 or as the mean value. This latter might not work well when using a broad interval, e.g. [-90,180] or [-180,180] because you might have two peaks, but it works well in [-90,90]. I also backported the changes to the LCD version (see attached image). The uncertainty on the vdi helps to fix its value, i.e. you need to move the search coil until you get a small uncertainty then you will have a good vdi measurement.