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

[MartyJ1963]

Nice little SMD board Goaty,,,I'm following your build with high hopes it works out the way you want it to,,,looking forward to your next posts,,,Regards,,,Marty.

[Goaty]

@F117
Thanks for the confirmation of the ICSP connections Bernard. That's how I interpreted it too. I wonder if Nick actually had it working the way it was?

@ Marty
I'm using an earlier version of the board layout at the moment but Nick's last version was the one in post #325. This is a little confusing as the zip file is pickini V4 4smd.zip but this contains the sprint file pickini V4 3smd.lay6 - there is a version in one of his earlier posts with the same name but contains un-corrected errors. All a bit confusing! I will have to cut tracks and add a link on my board to update it.
The tracks on this board are certainly very fine and proved difficult to etch - a commercial version would be a better proposition but I wanted to make sure it would work first. I used negative resist and a printed negative on oiled paper to make mine. It took a bit of scratching with a scalpel to clean it up for etching.
I must say I am enjoying the challenge of using surface mount components as it sure beats drilling hundreds of holes with a 0.7mm drill!

[MartyJ1963]

@Goaty,,,Me too,,,I recently got into SMD as well,,,it was diffcult at first but I really enjoy it now,,bit of a strain on the old eyes so I just do a couple of hours at a time,,,will you be updating the Pickini 4 SMD version when you've got it working? I don't mind ordering some from a pcb company later, and if you're based n the uk I could send you one (free),,,,hope your project goes well,,,keep us posted,,,Regards,,,Marty

[Goaty]

@Goaty,,,Me too,,,I recently got into SMD as well,,,it was diffcult at first but I really enjoy it now,,bit of a strain on the old eyes so I just do a couple of hours at a time,,,will you be updating the Pickini 4 SMD version when you've got it working? I don't mind ordering some from a pcb company later, and if you're based n the uk I could send you one (free),,,,hope your project goes well,,,keep us posted,,,Regards,,,Marty

Thanks for your kind offer but I am in Aus.
At this stage I am not sure about what I will do - a lot depends on how successful this build is. At the moment I am concerned about the orientation of the BS170 fet footprint. It seems to have the S & G pins transposed on the layout. I would appreciate it if you could let me know what you think. If it is wrong I think I can get around it by soldering it on upside-down but am wondering how Nick managed with the original. One thing I have noticed is that this layout is very similar to the original Pickini board as far as component placement is concerned.
Also, I am working on a programming socket for off-board programming of the sm pic chip. I will post details if it is successful.

[MartyJ1963]

@Goaty,,,Where about's in OZ are you?,,,I'm orginally from Dharruk, Mt.Druitt in Sydney,,,I was born at North Shore in 1963 and brought up in Mt.Druitt untl I was 14 in 1977,,,parents (Both British)won the lottery so they decided to uproot us and move back to England,,,never wanted to leave OZ cos' I loved doing Bushcraft and extreme survival,,tried doing it in England but it's not the same!,,,,Anyway,,less of that, Lol,,,I'm not really savvy on all the SMD parts as yet but I can take a look at the pcb you posted earlier,,,If you do manage to get a working SMD board and post your layout if I get some made later I'll still send you one or two (Free),,,,I'm stocking up on some pcb's for future use when Im bored/for friends/Winter projects etc,,I'm even remaking 8 different proven units I've already done at least twice for friends and also to keep in practise,,,I'll have a look at the lay and see if I suss anything,,Do you have a schematic for this particular board? Regards,,,Marty

[MartyJ1963]

I just took a look at the schematic I have for the Pickini 4 and it seems like the 'S' goes to ground but on the SMD pcb you posted it's 'G' that goes to ground,,,I posted you the datasheet for the MMBF170 (BS170 smd),,,don't know what to suggest apart from re-drawng the SMD board and try placing the MMBF10 upsde down in the same area? Regards,,,Marty

[Goaty]

I just took a look at the schematic I have for the Pickini 4 and it seems like the 'S' goes to ground but on the SMD pcb you posted it's 'G' that goes to ground,,,I posted you the datasheet for the MMBF170 (BS170 smd),,,don't know what to suggest apart from re-drawng the SMD board and try placing the MMBF10 upsde down in the same area? Regards,,,Marty

Thanks for confirming my suspicions Marty - I reckon if I 'flip the chip' for now I can blob solder it in place to test but it certainly looks like the board layout will need some mods. Progress on the prototype will slow as I run out of parts - I have more on order but they take many weeks to get here from China - I reckon our slow Customs processing has a lot to do with that.
OK on you being from Aus. I am in country Sth Aus - long way from Sydney. From what I have heard, it would not be a particularly good place to live nowadays with the traffic on the roads. Also, the bushfires on the east coast are pretty serious at the moment. My two boys are living in the Byron Bay hinterland but fortunately clear of the main fire areas for now, but still a worry.

BTW the circuit for this board is pretty much the original Pickini one. Also, another possible mistake spotted - resistor R10 is marked as 470 but is 4k7 on the original board and the parts list.

[MartyJ1963]

Hiya Goaty,,,Yes, Be careful out there,,,I've witnessed a few bushfires too in my time and even the smallest are not to be taken lightly,,,I got stranded once while camping in Glenbrook National Park (Near Katoomba) back in the 70's, the Park Rangers had to rescue me and my friends, Lol. There was a little pond/lake/Billabong called Jellybean pool,,we had to wade and stay in that till the rangers came,,a bit scary at the time but at about 10 years old it was an excting adventure too.
Yes,,When I looked at the schematic I noticed the same,,R10 is 4K7 and not 470R,,I've built 4 Pickini 4's for my partner and me and several for friends and all have worked first time by following Bernards schematic and original layout so I'd place all the original components first and then if you want to do mods it should be a lot easier with a fully working unit. It's pretty sensitive with original specs,,I found a gold ring with a diamond with the first one I built,,I used a 3DSS Coil with it-350uh/16 strand 600v ptfe wire,,works great. Just a thought, maybe you could drill a hole through each of the MMBF170 Pads, cut some small pcb pins and solder the mmbf170 from the other side along with the through-hole parts? Let us know how you go though,,,and hope you and your family stay safe and tajke care concerning the bush fires, hope the services get it under control soon mate,,,Regards,,,Marty.

[useus]

would anyone be able to create the hex file for PIC16F73?


thanks!

[Goaty]

@Marty
Thanks for your concerns - it's certainly a worrying situation for a lot of people. Hats off to the 'firies' who do an amazing job fighting these fires.

Re the smd Pickini project, progress has slowed at the moment waiting for parts but I have made a programming socket to hopefully enable programming of the 14 pin smd Pic 16F1864.



It seems to hold the pic securely enough (upside-down!) and make good contact with the pins. The contacts have been cut from a 32 pin PLCC sm socket soldered to pads scribed into a scrap of PC board using the back of a scalpel blade. I had to fit a strip of plastic into the bottom of the socket to pack up the chip so its legs make more secure contact with the sprung socket contacts. I can't test it until the 16F1864s arrive - It just has a 'dummy' chip in it at the moment.
I think off board programming may be a better proposition as in-circuit programming may require isolating too much of the other circuitry to make it effective.

I have also spotted another problem with the board layout - the S pin of the IRF740 goes to an isolated pad. It needs to go to ground.

[bernte_one]

would anyone be able to create the hex file for PIC16F73?


thanks!

just insert the code i a windows notepad editot txt file, save it as pickini.hex instead of pickini.txt
easy or?

[useus]

just insert the code i a windows notepad editot txt file, save it as pickini.hex instead of pickini.txt
easy or?

I asked to rewrite the code for pic16f73

[F117]

I asked to rewrite the code for pic16f73

That won't be possible. As I told before, the design is relying heavily on built-in resources like a gateable timer, internal 32 MHz oscillator, DAC output, ADC and analog comparator inputs ...

After a quick look at the datasheet of the pic16f7x:
https://ww1.microchip.com/downloads/...Doc/30325b.pdf

A lot of the required resources are missing !

[useus]

thank you, I buy a correct pic

[waltr]

@Marty
Thanks for your concerns - it's certainly a worrying situation for a lot of people. Hats off to the 'firies' who do an amazing job fighting these fires.

Re the smd Pickini project, progress has slowed at the moment waiting for parts but I have made a programming socket to hopefully enable programming of the 14 pin smd Pic 16F1864.

[ATTACH]48329[/ATTACH]

It seems to hold the pic securely enough (upside-down!) and make good contact with the pins. The contacts have been cut from a 32 pin PLCC sm socket soldered to pads scribed into a scrap of PC board using the back of a scalpel blade. I had to fit a strip of plastic into the bottom of the socket to pack up the chip so its legs make more secure contact with the sprung socket contacts. I can't test it until the 16F1864s arrive - It just has a 'dummy' chip in it at the moment.
I think off board programming may be a better proposition as in-circuit programming may require isolating too much of the other circuitry to make it effective.

I have also spotted another problem with the board layout - the S pin of the IRF740 goes to an isolated pad. It needs to go to ground.

That should work and an inventive solution.

However, an ICSP header is really the way to go and circuit can easily be designed to isolate other circuits without impairing their function.
First is a diode & 10k pull-up from +5V to MCLR/Vpp and a Schottky diode from +5V to PIC's Vcc to prevent powering +5V from the programmer.
Series resistors between the PIC's PGD & PGC pins to other circuit if used. I try not using these two pins so that I can use them for In Circuit debugging.

Here is the schematic of the universal 18pin PIC boards I use.
PIC- 16F88 sch.pdf