EasyEDA first order problem.

[Pommie]

I've designed a small board with EasyEDA and now want to order said board. I've uploaded all the required files and get to the quote page which has a review of parts placement.
This is what I see,

As you can see, all the parts are shifted left by 0.1" and I've no idea how to correct this or even if I need to!

In the EasyEDA software I see the following 3D view,

Anyone any idea what (if anything) is wrong?

Mike.
Edit, on the quote page below the above (wrong) image it states " The parts placement is for reference purpose only. If you are sure the rotation and polarity of your design are correct, you can omit the preview and continue placing your order."

 

[Pommie]

As a check I replaced and rerouted the board but the results are the same.

Mike.
Edit, this is the routed board in EasyEDA.

 

[Visitor]

That's very weird. Don't know what to suggest. Somehow, the pick&place file is shifted.

I had a problem on my last order where one chip (a CH340G) was rotated 90° from the mounting pattern. I edited the rotation angle in the pick&place file to get the orientation to be correct. I'll post a picture later (it's 2:30 AM at the moment....yawn).

 

[Pommie]

As I'd used the symbol for a 18 series pic (pin identical) I had changed the serial number and description to use the better 18 series symbol - same footprint. As this was unconventional, I redid the schematic with the correct everything and rebuilt the board. The result was even more in error,

It's very weird, I've sent them a help request, hopefully get a reply in the morning.

Thanks for looking.

Mike.

 

[Pommie]

I've got a reply from JLCPCB stating,

Actually the online preview of the placement view is for reference purpose only and it may occurs errors.

You can directly ignore those offset positions and proceed.

I'm thinking tomorrow (11pm here) I'll redo it with a better chip (16F1936 has LCD driver functionality that may complicate things). I'll see what's available and spend a couple of hours (yup, that short a time) redoing it all and see where it leads. If I get an offset error then I'll just add it as a note.

Looking forward to getting (semi) made boards. Well, all the hard bits done.l

Mike.

 

[Visitor]

Here's the problem I had, where the chip was 90° to the footprint.

 

[Pommie]

Redid it today and all seems correct. Then changed to a QFN-28 package and then the Autorouter seems to have stopped "tidying up". This is what it does,

You see the weird squiggly tracks just below the QFN package! I've tried both the online and stand alone router with the same results.

I know it will still work but it's just messy. This can't be how it's supposed to work can it?

Jon, if the package says no stock does that mean it will be left vacant?

Mike.

 

[Visitor]

Nobody likes the autorouter. Or any autorouter for that matter.

If it says "no stock", that footprint will be blank when you receive the board.

When you submit the file, that position won't show a component, and the bill of material will have that part grayed out.

 

[Pommie]

Thanks Jon,

Yes, I just submitted and got an empty space. Back to the drawing board.

Mike.

 

[Visitor]

The PIC? Is there an available variant with more memory ?

 

[Pommie]

I ended up with a SSOP-28 version. It's an I2C backpack for a character LCD - weird how I now find SOIC too big!!!! I've now changed to the 16F18854 which meats my needs nicely.

Here's the schematic, spot any obvious mistakes?

I decided to try PWMing the V0 via an RC filter.

Wow, just spotted the current limiting resistor for the LED is in the D7 line!!!! Good job I always wait at least two days before ordering as I've always forgotten something or thought of something I can add.

Mike.
Edit, updated.

 

[Nigel Goodwin]

I've been using PWM for the contrast for a good while now, it allowed me to drop the pot from the board and preset the contrast value in the software (stored in EEPROM), and adjustable from buttons on the front panel - and it avoids any setting up during manufacture. I used a 1K resistor and a 10uF for the PWM.

I notice you've got a diode in the Vpp/Vdd programming circuit - as far as I'm aware MicroChip dropped that requirement a very long time ago, and now just recommend a 10K resistor. Obviously it's perfectly fine though.

 

[Pommie]

The luxury of having a machine making it for me "Forced" me to include the "unnecessary" diode.

Mike.

 

[Pommie]

The more I use EasyEDA the more I like it. This is the final final schematic (I think).

If anyone spots any mistakes then please let me know. I'm really surprised how big an 0603 LED appears to be! Plus, how tiny those resistor arrays are!

For anyone curious it's an I²C backpack for an LCD. The available ones take 1mS per character to update so for a 20x4 LCD it was taking 80mS. This manages in 6mS so I'll now be able to do a scrolling up/down menu system. As the pic had lots of memory left I've added the 8 expansion ports and the ability to save variables in the Pics EEPROM.

Mike.

 

[Pommie]

OK, first board should arrive next Tuesday. Now, I'm trying to design a board that uses several opto reflectors. JLC have one designated EE-SY193 but the stock is zero. Is there anyway to order these from elsewhere or request JLC to order them. I'd need about 160 and really don't want to solder them by hand.

Mike.

 

[Visitor]

I think gophert said he's made some parts requests and they've added parts to the library.

 

[Visitor]

This Hack-A-Day article has a parametric search engine for the JLC library. It looks like it might help sorting through components a little easier (although probably not much help in this case). Seems to work pretty slick.

Improved Part Searches For JLCPCB Parts

Finding the JLCPCB component parts library frustrating to navigate, [Jan Mrázek] took matters into his own hands and made an open-source parametric search utility. We’ve all probably wasted t…

hackaday.com

 

[Pommie]

Just thought I'd follow up on the above. Well, the boards arrived 8 days after placing the order.
And very nice they are too,

However, I discovered a few thing. I'd gotten the anode and cathode of the backlight the wrong way around.
Filtering the PWM for the contrast didn't work with a 4k7 resistor and a 10uF capacitor. The contrast pin appears to supply a current as even switching the output to zero resulted in 1.5V on the contrast pin. To fix it, the two components in the top right are the resistor and capacitor, so I soldered a 1K 1206 resistor diagonally between the bottom of the resistor and the top of the capacitor and all works well.

The final board on the back of a 20x4 display. You can just about see the ugly 1206 resistor!

So, once completely debugged I'll order a new set of boards and consider it a cheap (AU$60) learning experience. Oh. one more thing I hadn't realised, in my search for Pics in stock I'd gone through many different ones. I thought I'd picked one with 8K flask and 2K ram. Nope, 2K flash and 512 Bytes of RAM. So far I've used less than half of each and the code is near complete. Phew.

Mike.

 

[schmitt trigger]

EasyEda is really a breakthrough innovation.

It allows plain people to tap into China’s ultra effective manufacturing capabilities.

 

[Visitor]

Great looking board. Nice that the little oversight was fixed without too much trouble.