PI CHIP

[moodz]

test results UNIPI chip v23

tx timing and s1 s2 sample pulses.

using the rotary encoder we dial up 2.000 khz TX rate and 100us tx pulse ...
then set s1 and s2 sample pulses ... dial up start time and stop time for each in us.

pix below .... have not included the pix for s2 stop and start times because of 5 pix limit on posts.

moodz.

[moodz]

updated UNIPI CPU schematic.

- added LCD bias generator for LCD contrast control ( fixed in code .. but could be variable )
- rotary encoder / PB switch added for menu.

moodz

[moodz]

v22 final menu update

...well another day .....another feature

Reorganised the code to now suck 18 bit resolution out of this sucker ... The static LCD display was pretty boring so another code tweak puts the SAT level and the Target signal on the default display .... if you press the select button you will still run through the menus published previously.

The target value updates 32 times a second ( LCD updates target 2 times a second cos you cant see it update at 32 times a second )

resolution is now 20 microvolts .... not bad for an integrated 10 bit converter with no components other than code ....

series of shots of the main LCD display below ... no changes to the other menus previously published. The display has settled and is displaying the target level top and absolute SAT level below. The display reads in volts with +/- 2.5 volts top 0 to +5.0 volts bottom ... 6 decimal places. Note there is no "front end" attached here.

cheers from moodz.

[moodz]

The audio generator is very simple ... if there is no target you hear like a ticking noise .... a target will increase the frequency ... The audio rate is like a multiplier ...

eg
Audio rate = 0 no target = 1 hz ticking noise small target = 2 hz ticking noise

Audio rate = 100 no target = 100 hz small target = 200 hz

hope this makes sense .... maybe I should call it Audio multiplier.

regards,

moodz.

ah .... you have made me realise there is a bug in the code ( sort of ) ... if a large target comes along the audio frequency will go above human range of hearing .... ( maybe your dog will hear it though ).... I will put a limit in.

moodz.

[moodz]

Good work moodz.

What mean audio rate value?

The audio generator is very simple ... if there is no target you hear like a ticking noise .... a target will increase the frequency ... The audio rate is like a multiplier ...

eg
Audio rate = 0 no target = 1 hz ticking noise small target = 2 hz ticking noise

Audio rate = 100 no target = 100 hz small target = 200 hz

hope this makes sense .... maybe I should call it Audio multiplier.

regards,

moodz.

[WM6]

Good work moodz.

What mean audio rate value?

[moodz]

v22 final menu ( sub menu )

.... sub menu added so you can change the timings, save them etc

Push click rotary switch to enter sub menu ... push click again to exit after making selection.

change current value by in x 1 steps .... ( step = 33 ns or 66 ns depending on timing being altered )


change current value by x 10 steps ...


change current value by x 100 steps ....


save to eeprom ...


exit and back to main menu ...

[moodz]

v22 final menu

Main LCD menu finalised and operational ....

powerup screen ..


TX frequency / period ..


TX Pulse duration ...


sample pulse 1 ON (delay from start of TX )


sample pulse 1 OFF (delay from start of TX )


sample pulse 2 ON (delay from start of TX )


sample pulse 2 OFF (delay from start of TX )


Audio rate

[moodz]

quickie update.

Cleaned up some minor bugs.

Add submenu to LCD control so that rotary update of values can be X1 X10 X100 ... otherwise it takes a long time to change the TX frequency from 500 Hz to 20 Khz in 33 ns steps.

moodz.

[moodz]

UNIVERSAL PI CHIP v2.2 UNIPI update.

..fixed issue with negative ve required by LCD. Added two caps and two diodes to secondary PWM TX output and voila .... LCD works OK ...

Menu is now working and fully operational.

Turning the rotary switch changes from TX Freq, Tx pulse, sample pulse 1 ON , Off etc etc.
Pushing the rotary switch allows the currently displayed value to be changed.
Pushing the rotary swith again saves the updated value to EEPROM.

The serial menu is simultaneously available and independant of the LCD.

I have uploaded a few menu shots ... there are more ... all operational ( can be selected, changed and saved ).

moodz

[moodz]

update images

....bread boarded the last published PI chip circuit and all works ....except ... the contrast on the LCD wants a -volts bias .... buried away in specs so display is very faint. Need a negative bias generator to provide this or use other type of LCD ... this was a Powertip 1602-H.
Schematics OK ....
rotary OK ...
LCD OK ( add -ve bias for contrast )

Menu code under construction ... should be OK.

moodz.

[moodz]

quick update

Ok Moodz, I dont want to push you or disturb your great work.

Only reminder, because I am not quite well to put togheter puzzle pieces from different forums and posts.

Best wishess

Thanks WM6 ...

The Rotary Encoder code is now debugged and working.
The LCD code is now operational and under debugging. ( tip ....dont use Powertip 1602-H LCD displays ... the contrast control is non standard .. spent lots of time looking at blank display thinking code was not working when it was the contrast all the time ).
As soon as the LCD checks are complete .. hopefully tonite ... the LCD menu will go in ... easy street now.

moodz.

[WM6]

Previously I have worked from frontend to back end ... this time I am working back to front (end) .... I will tweak code bit more then publish rest when tested ... patience please.

wont be long.

cheers from moodz.

Ok Moodz, I dont want to push you or disturb your great work.

Only reminder, because I am not quite well to put togheter puzzle pieces from different forums and posts.

Best wishess

[moodz]

Thanks moodz,

please, post here last version of other stages (frontend ...) too.

Previously I have worked from frontend to back end ... this time I am working back to front (end) .... I will tweak code bit more then publish rest when tested ... patience please.

wont be long.

cheers from moodz.

[moodz]

RS232 interface in EAGLE