PICKINI V4 - an easy to build, self adjusting PI detector

[scrungy_doolittle]

the problem I have with these pics is that they require a header to program. Now: how about just putting a 6 pin .1 inch header on the board and hooking it to the correct pins, so those of us with an ICD3 or PIKIT3 can simply program the chip in place?

[waltr]

the problem I have with these pics is that they require a header to program. Now: how about just putting a 6 pin .1 inch header on the board and hooking it to the correct pins, so those of us with an ICD3 or PIKIT3 can simply program the chip in place?

I agree and do put the ICSP header on all my PIC project PCBs.Sure makes code loads and updates very easy and quick.
I can simply open the box of my HH PI detector, plug in the PICKit2 and a few mouse clicks have code updated.

[F117]

I agree that having an ICSP header is easy to reprogram the PIC without removing the chip. However when you are playing with settings like pulse delay/width, I would prefer a bluetooth serial link and modify settings via a smartphone and an app like blueterm + store these settins in the PIC EEPROM. This allows for generic fixed code and flexible settings parameters. The code itself could be fixed and simple: generate a tx pulse (setting = pulse width), take a sample some time later ( setting =pulse delay), etc..
This way, anyone can adapt all settings personally. I usually use the bluetooth module only for debugging.

[scrungy_doolittle]

My point was that the pickini, and the vdi and any other pic based project, needs the pickit programming header laid out on the board. Having worked extensively with the RN4020 blue tooth module, I can tell you that you don't want to try to use it. It is buggier than you can imagine. I worked on a medical instrument that used a PIC24 to control 2 8051 based electric stimulators (which by the way, used a flyback for generating a +/- 700 volt, nano amp stim pulse). An app on a tablet was supposed to communicate with a PIC24 through the RN4020, using the MDP serial protocol. What a nightmare!

[waltr]

^ Exactly. Just Flashing code into the PIC the first time is worth putting the ICSP headed on the PCB.

[scrungy_doolittle]

I just hope the OP will take this to heart, and relay out the board.... to include the ICSP pins on the board.

[F117]

The 'short term' plans for this project would be to include a bluetooth 9600bps serial interface to allow anyone to change all settings - including temporal/voltage sampling - and store these settings in eeprom. When you look at the schematic of the felezjoo detector and pickini v1, there are many similarities. The same hardware could be used for pulse width measurement or classic voltage sampling

[sinclairuser]

hi all, not far off finishing now.
aly.

[F117]

Nice looking board !

I can see you used a range of different 100 nF caps. In theory they should all be ceramic, but this most probably won't effect the functionality.
I also never placed a heatsink on the MOSFET. With the standard 100 microsecond pulse width, that should not be a problem.

Regards,
- Bernard

[sinclairuser]

thanks bernard, i only use ceramics in really small values, i like box caps in amps and detectors just a personal preference, i once had some bad ceramics that caused oscillations, as for the different types i would have used red wima's in all positions but couldn't find my box of them, by the time i found them i had already built the power supply.
as for the heatsink i bought some for a repair i did that used 26 of them and the cheapest way to get a quantity was to buy 100 of them so every mosfet or regulator in that package gets a heatsink just to use them up.
aly.

[ripsdevala]

Hello benard,
One of my collage ask me to create 1x1m sensor for 1m+ deep for big target, lets says 10x10cm plate, beach area.
What should i need to modify, and what is the parameters of the coil?

[F117]

I summarized some popular coil dimensions here:
http://users.telenet.be/willaert/MD/...n/V3/coil.html
For a 1m coil I usually take 5 twisted pairs from a network cable - 4 m long.
In a standard CAT4 cable, there are 4 twisted pairs, so you will need another length of 4 m for the 5th pair.


Bundlle them together in a new cable by wrapping it with electrical insulation tape:



Then a layer of shielding ( alu foil eg ) and then another layer of electrical tape.

You can then place the cable in a PVC drain pipe frame and connect the ends of the wires to have a bundled coil of around 350 microHenry and 2-5 ohm:



Add a control box with batteries:



Drag it behind you, carry it or mount it on plastic wheels:

[ripsdevala]

No need to modifying the circuit and firmware right, i read on this thread to increase the pulse timing for better results. I will create the 1x1m sensor first. Thanks

[6666]

That cart is a great idea.

[ripsdevala]

What about cat5 cable, i can't find any stranded cat4 lan cable.
Theres a metal rod on the cart wheels, is that okay?