VDI-RODERICO

[waltr]

Can the PIC18F26K22 be programmed with a simple programmer? I have an Epicprogrammer I use for F16F88.

Check the document for that programmer to see if it supports the 18F26K22.
I use the PICKit3 for the 18F26K22 and a PICKit2 for the 16F88.

[Wiltran]

Can the PIC18F26K22 be programmed with a simple programmer? I have an Epicprogrammer I use for F16F88.

[Albdelafar]

Thank you very much roderico !!

I think I posted a pdf file of the PCB and or the Gerber files. If not and you want them let me know.
Then use these as an example.
It is always good to know how to do a schematic and PCB. It isn't really hard and then allows you to do any PCB project you went.

I got them !! I finished some minor modifications to the IDX PRO layout now I will try to adapt the VDI PCB to it.

[roderico]

I have rebuilt the missing firmwares for PIC18F26K22 in case it helps although they are untested they should work. PIC18F26K22 is basically PIC18F25K22 with double program memory (64K vs 32K) and more data memory (>2x) as waltr has pointed out, but v2.2 only uses 60% of 32K so both pics should be equivalent for the vdi. S6B0108 is the same as KS0108 but with inverse CS1 and CS2.

[waltr]

Do I have a way to know if the .hex is good before to send it in the PIC?
For the PCB layout I will try to do it by myself it's could be a good exercise !!

If you mean will it run, then No you just load it into the PIC and see if it runs.

I think I posted a pdf file of the PCB and or the Gerber files. If not and you want them let me know.
Then use these as an example.
It is always good to know how to do a schematic and PCB. It isn't really hard and then allows you to do any PCB project you went.

[Albdelafar]

Thank you roderico and waltr for the very interesting information. I am here to learn and by reading posts like this I learn a lot.
Even if it is a bit hard to record all the information sometimes .....
Tommorow I will try your tutorial waltr. Do I have a way to know if the .hex is good before to send it in the PIC?
For the PCB layout I will try to do it by myself it's could be a good exercise !!

[waltr]

hi roderico and waltr I follow your post with interest
I bought an Oled ssd1309/ssd1305 but there are four interfaces depending on resistors position on the backplate : parallel 6800 or 8080 and serial or i2C. Do you know what interface i need to use with ssd1305 drivers ?
Thanks.
I have a PIC 18F26K22-I/SP so you did a .hex with this PIC but with another screen and another with this screen but with another PIC. I installed MPLAB X but i do not know how to modifie text files and how to compil them in .hex. I found the .hex for the PIC 18F26K22 but not the .h or .c too. Do you know where i can found a document or video who explain how to do this ?
And last thing, Waltr I want try to add the op-amp stage to your universal display PCB. Do you have a sprint layout that i can modifie ?

Sorry, no sprint layout. I do all schematic and PCB in an old version of PCAD.
I put the op-amps on a separate board that is mounted inside the box with the TGSL board. Then a cable to the display board.
This keeps the high gain amps and connections onto the TGSL's board shielded.

Microchip has tutorials on the basics of using MPLABX. You need to start a New Project, Microchip Embedded, Standalone. Select the device (Advanced PIC18 family - PIC18F26K22), then compiler (XC8 ), Project name and folder for the project.
Copy Redgerico's source code files into the project 'source' folder'. Then in "Projects" window,Select 'Header Files and Right click- select Add existing Item... In the dialog that open go to the folder with the source file and select the *.h (header) files.
Do the same with the "Source Files" and select the *.C files.
There are .h & .c files for different PIC. Only select the Pic you are using, ei _18f25k22.* but select all the other files.
The display files are in the glcd sub-folder. Again for different displays. Select only the ssd1305.*and then all the other files.

There will be a few minor code changes needed to use the 26k22. Easiest to do is Compile then click on the errors to see what code lines need to be changed.
Along with Microchip's tutorials there are same simpler example projects. Download these to learn how to use MPLAB. The first few times is hard since there is a lot to learn but then it gets easy.

hi you need parallel 8080 interface, if you are using the same pin configuration as waltr's then maybe waltr can post the firmware it would be easier, if not I can build the firmware for you but with the same pin configuration as the ST7567...

Correct 8080 parallel mode.

in principle it should work, but e.g. waltr has problems with VDI numbers when using with TGSL as X,Y depends on disc, phase difference is extracted from X Y amplitude ratios as atan(y/x), it builds a histogram with each X,Y pair sampled from a short time window, the same target might give different histograms depending on sweep speed, orientation, position of the target, ... when you have a narrow histogram (low error) you have good id, e.g. non-ferrous metals, ferrous metals on the other hand usually give a wide histogram and thus variable vdi numbers. Depth can be tuned with trigger level and/or with the op-amp gain, in summary I would just say that it helps but it does not do miracles, maybe someone else has done some more tests and can post results here

Correct.
The VDI display does not affect the detectors (TGSL in my case) depth detection.
The VDI just helps to determine what type of target might be there.
Even though the VDI numbers are different on my TGSL than the IDX it is really the X-Y Graph that I go on to help determine if I dig a target. It is simply getting experience with the VDI as you would need to do on any detector. The VDI is very helpful when there is a good target near iron and you sweep the coil around the iron/target. When the coil is just missing the iron the X-Y graph shows a positive sloping line.

[roderico]

Could 2.2 be used with various metal detectors Gold Mask, Tejon etc. with X, Y channels? Also any comments about VDI accuracy and depth.

in principle it should work, but e.g. waltr has problems with VDI numbers when using with TGSL as X,Y depends on disc, phase difference is extracted from X Y amplitude ratios as atan(y/x), it builds a histogram with each X,Y pair sampled from a short time window, the same target might give different histograms depending on sweep speed, orientation, position of the target, ... when you have a narrow histogram (low error) you have good id, e.g. non-ferrous metals, ferrous metals on the other hand usually give a wide histogram and thus variable vdi numbers. Depth can be tuned with trigger level and/or with the op-amp gain, in summary I would just say that it helps but it does not do miracles, maybe someone else has done some more tests and can post results here

[roderico]

hi roderico and waltr I follow your post with interest
I bought an Oled ssd1309/ssd1305 but there are four interfaces depending on resistors position on the backplate : parallel 6800 or 8080 and serial or i2C. Do you know what interface i need to use with ssd1305 drivers ?
Thanks.
I have a PIC 18F26K22-I/SP so you did a .hex with this PIC but with another screen and another with this screen but with another PIC. I installed MPLAB X but i do not know how to modifie text files and how to compil them in .hex. I found the .hex for the PIC 18F26K22 but not the .h or .c too. Do you know where i can found a document or video who explain how to do this ?
And last thing, Waltr I want try to add the op-amp stage to your universal display PCB. Do you have a sprint layout that i can modifie ?

hi you need parallel 8080 interface, if you are using the same pin configuration as waltr's then maybe waltr can post the firmware it would be easier, if not I can build the firmware for you but with the same pin configuration as the ST7567...

[Albdelafar]

hi roderico and waltr I follow your post with interest
I bought an Oled ssd1309/ssd1305 but there are four interfaces depending on resistors position on the backplate : parallel 6800 or 8080 and serial or i2C. Do you know what interface i need to use with ssd1305 drivers ?
Thanks.
I have a PIC 18F26K22-I/SP so you did a .hex with this PIC but with another screen and another with this screen but with another PIC. I installed MPLAB X but i do not know how to modifie text files and how to compil them in .hex. I found the .hex for the PIC 18F26K22 but not the .h or .c too. Do you know where i can found a document or video who explain how to do this ?
And last thing, Waltr I want try to add the op-amp stage to your universal display PCB. Do you have a sprint layout that i can modifie ?

[Wiltran]

Could 2.2 be used with various metal detectors Gold Mask, Tejon etc. with X, Y channels? Also any comments about VDI accuracy and depth.

[roderico]

the code to drive a buzzer could be used for that but it requires to free the backlight pin and move it e.g. to the open drain and but it is not backwards compatible with v2.x (this pin should be freed in v3.x) https://www.geotech1.com/forums/show...896#post263896

IMO a more simple a better solution is to use a BMS for Lipo batteries, they are really cheap in ebay 1-2 USD and have over-discharge protection to avoid to ruin these batteries which are very expensive (the alarm might not always work, e.g. if you are away and left the detector on). I've been using three 18650 batteries with HX-3S-01 BMS and have always worked well for me.

[waltr]

Great work again. Thanks.

I do have a feature request. It will need one more PIC pin as an output but should be doable on all existing PCBs.

Feature is a Low Battery Alarm.
Idea is if Battery Voltage drops below a programmable threshold than a piezo buzzer is "chirped' say every 5-10 seconds.
This 'chirp' can be like the low battery warning found in smoke detectors.

Reason is I have left my detector On without noticing and the LiPo battery drain until a cell went to zero Volts. this Killed the battery pack. If it 'chirped' then I would have known to check the detector and turn it off.

??possible??

[roderico]

vdi 2.2

This is version 2.2, the main changes with respect to version 2.1:

- ST7567/ST7565 display driver (kroman01's request)
- SSD1305 display driver (waltr's mod)
- initial 3.3V support (waltr's mod)
- "frame" theme (kroman01's request)
- change XY graph to 64x64 pixels
- updated led version

to rebuild the firmware (e.g. if you want to change pin assignments, new pic, etc.) it is sufficient to set define variables in the compiler options of your project, in section "preprocessor macro definitions" or "define macros", e.g. for waltr's mod you would need to add: _P18F26K22, _SSD1305, _VDD3V3 and it should compile fine

[roderico]

I updated the schematics with all the changes so far for v2.2, although you do not need to change your pcb as the firmware should work with all pcb v2.x. I left the voltage divider for 3.3V since there is no clear replacement for MCP1525. The MCP604 is optional but it gives a narrower filter and no phase different between input and output signals, R16 might not be necessary, if there are no more bugs then the firmware could be released as v2.2.