PICKINI V3 - an easy to build PI detector

[tclow]

for pin6, No, it fixed at -0.45V
for pin1, No, it fixed at 0.5V, btw, isn't it suppose to be 0 as it connected to ground?
for pin7, No, it fixed at 10.6V
btw, I am not sure about connection at x4..
i did the connection as:
x4-1 - 12V
x4-2 - R19
x4-3 - R18 - P6 of PIC
x4-4 - GND
is it correct?
The whole circuit is built on breadboard and using breadboard stick as supply (not battery)

[bernte_one]

[F117]

for pin1, No, it fixed at 0.5V, btw, isn't it suppose to be 0 as it connected to ground?

NO - it should be 6V:
Pin 1 of the opamp is "virtual ground" = VBatt/2 - connected only to D3, R4 and R13 - marked on the schematic as "DGND". Do not connect pin 1 to GND = minus pole of the battery - marked as "GND" on the schematic !

Hope this helps,
- Bernard

[tclow]

Thanks bernte_one!

[tclow]

I see, made a mistake there.. now i changed the connection, the value is now full VBatt...
at pin7 value goest to 1.58V and pin6, also around VBatt..

i'm now trying to work directly on PCB.. see if it works.. currently the circuit is built on breadboard with DC supply..

[tclow]

Now i get 5.92 - 6.05 variation at pin6 of opamp
Vbatt/2 at pin1
but at pin7 still fixed at around 1-2V less than Vbatt..
btw my Vin is 13.05

*my PCB trial failed ><

[F117]

Pin 7 at around 10V is OK. It is divided by 2 towards pin 3 of the microcontroller.
I quote the adjustment procedure :

Adjustment:
Adjust the DC offset of the opamp output with multiturn R23:
Measure the DC voltage at pin 3 of the PIC12F1840 and adjust from low voltage until 5.3V is reached.
Stop adjusting when 5.3V is barely reached.
The voltage won't go any highter since it is clipped internally in the microcontroller with a diode to 5V.

http://users.telenet.be/willaert/MD/...ectronics.html

*my PCB trial failed ><

It is a simple single sided PCB and easy to stuff. You can make bad solder connections, stuff the wrong components at the wrong place, short a couple of traces, but what else could possibly go wrong ...

[tclow]

Finally the circuit works, thanks a lot for sharing =D
For the circuit on breadboard, the response is kinda unstable sometimes, is it probably because of the noise of surrounding?

[bernte_one]

hello tclow

the circiut needs some minutes to stabilize
at start you will see the sens it not so high like the detector is switched on for 2 minutes

do not trun the sens pot to high
i remind if you turn it half way you even got the max sens

[F117]

For the circuit on breadboard, the response is kinda unstable sometimes, is it probably because of the noise of surrounding?

Test your circuit outside the house, away from large metal structures
and EMI. On a breadboard, longer leads on components may act as antennas.
The sensitivity can be cranked up full range -- on a deserted beach.

[Beenthereuk]

In fact, test away from any buildings - at least 2m away from a wall, etc. Best go into an open field.

[Guzzi]

Hello All

Can i use the same methode, with the 5 pins, to program the PIC as in the book ITMD on page 165?

regards

Leendert

[F117]

The in-circuit programming method, as described in the book on page 165 (complete PI2 circuit) should work.
I haven't tried it yet and the connector is also not foreseen on the PCB.
I program my parts with the PicKit3 programmer.
But I don't see why it shouldn't work when you attach the programmer directly to the pins on the PCB.

- Bernard

[Beenthereuk]

From what I remember, the circuit uses both the ISCP DAT and CLK pins so may or may not work depending on the load placed on those pins by circuit components. You can code it directly, outside of the circuit, by using this sort of clip attached to the IC and to the PICKIT programmer:
http://www.ebay.co.uk/itm/6-x-Single-Hook-Clip-Grabbers-Test-Probe-cable-for-multimeter-wire-lead-/151684532231?pt=LH_DefaultDomain_3&hash=item23511a 4807

[tclow]

great input, thanks all the gurus ~ =D