need a help with PCB.

Status
Not open for further replies.

D1 = 1N4007
XTAL= 4MHz
voltage reg= 78L05


sorry for Y2,
actually i was connecting it to suit my needs, i.e for the LC-display....

LCD pins arrangement: 14-13-12-11-10-9-8-7-6-5-4-3-2-1-16-15
with pin 1 as GND and pin 2 as voltage supply and pin 3 contrast adjust.

file attached.
 

Attachments

  • pc1602f.pdf
    58.9 KB · Views: 286
Last edited:
silvarblade said:
hi boncuk how did you edit his drawing using eagle?cause an eagle template is different!
Click to expand...

Hi silvarblade,

I'd like to explain it to you, but I'm afraid I make your brain explode.

Now seriously: You can't edit a drawing importing another file format to Eagle. I just printed the original schematic and made it all new using Eagle.

Hans
 

Hi t.man,

an 1N4007 is a bit overkill for false polarity protection. It can handle 1,000V.

are you sure you can get a 4MHz XTAL in a mini-package? I've seen these crystals only as 32.768KHz devices in clocks. Normal cyrstal package is HC-18, or the bigger one HC-49.

I strongly recommend to leave the pin arrangement of Y2 in a logical sequence. It is always better to have a few jumps on a single sided board than a smoking display and/or MCU. The additional advantage: You can plug the display directly onto the connector.

Depending on the backlight you use LED/edge or LED/array the 78L05 won't suffice. The LED/array requires 120mA!

Anyway to avoid overheating of an 78L05 I'd stay with the 7805. It doesn't occupy that much space.

Hans
 
connector Y2

Hi t.man,

I just checked the schematic and according to your pin arrangement of Y2 it would look like this: (values in paranthesis are true values for normal connections)

14(1), 13(2), 12(3), 11(4), 10(5), 9(6), 8(7), 7(8), 6(9), 5(10), 4(11), 3(12), 2(13), 16(15), 15(16)

To proceed with the layout there is some info required, mainly because there is an obvious error in connecting the LC-display. At least one data line is missing.

Please label all nets in and out of the MCU. This isn't only helpful for proper layout planning, but also useful for trouble shooting.

Make it look similar to this:
 

Attachments

  • Y2.gif
    20 KB · Views: 164
I feel the contrast Potentiometer pin1 should be to Vcc and not to Vee , though some people connect a sing le resistor from Vee to ground. In such case the pot is not needed. perhaps the designer should address this aspect.
 
mvs sarma said:
I feel the contrast Potentiometer pin1 should be to Vcc and not to Vee , though some people connect a sing le resistor from Vee to ground. In such case the pot is not needed. perhaps the designer should address this aspect.
Click to expand...

I don't feel it. I know it.
 
Boncuk said:
better now?
Click to expand...
the cross pinning shown is perhaps not correct. I saw and heave these 1602 models. the pins order is shuffled and datasheweet is tallying with what LCD panels I have.
Seceially to mention that pins 1 to 14 are shown right to left and 16 and 15 follow at the right of pin1. If, J6 is the connector meant for this 1602 type , thw wiring order is to follow the datasheet perhaps. if JHD type is used, the connector works straight.

the Contrast mod appeared OK.
i missed an observation that the limiring resistor is conventionally kept on LED+ (pin16) but it is now on 16/ should not matter seriously but might confuse others at the edge connector shown.

You have indicated that "atleast one dataline is missing" which wire Boncuk?
 
Last edited:
mvs sarma said:
You have indicated that "atleast one dataline is missing" which wire Boncuk?
Click to expand...

Normally LC-Displays are driven in 8-bit or 4-bit mode. Obviously the 4-bit mode is selected. However that requires nets to pins 4(RS), 5(R/W), 6(E) and pins 11 through 14 (D4..D7), besides VCC, VEE and ground + back light connections. Counting the nets there is one missing.

The current limiting resistor is placed into the ground connection because I use it as a jump in my PCB-layout.

Boncuk
 

You may have to consider - back lit as another pin. this the count is complete.
 
mvs sarma said:
You may have to consider - back lit as another pin. this the count is complete.
Click to expand...

Go ahead and solve the riddle with 'diced pin numbering' and the unlabelled nets.

The LC-control connections are non-standard. Normally the display is connected to port C.
 
Boncuk said:
Go ahead and solve the riddle with 'diced pin numbering' and the unlabelled nets.

The LC-control connections are non-standard. Normally the display is connected to port C.
Click to expand...
There is no riddle and I use this kind of LC displays Boncuk !
 
Although i am not the professional PCB designer, but our company specialized in PCB designer, PCB prototype, Circuit card assembly, you could enter into our website-http://www.pcb-assembly.com.tw, and try to contact them, maybe you could get a best answer. Hope you could find the best reply asap.
 
hi Boncuk,

following your layout, i've been able to come up with this:

what can you say?
 

Attachments

  • FORUM1.PNG
    58.7 KB · Views: 191
I had preferred you come up with a revised schematic having labels at the nets.

The layout looks OK so far with the exception of the "Christmas tree" underneath the ATMEGA16.

There is a more elegant way to route the traces.

Boncuk
 

Attachments

  • FORUM01.gif
    35.6 KB · Views: 172
  • FORUM02.gif
    15.9 KB · Views: 180
Status
Not open for further replies.

Similar threads

S
  • Question
Need help with spst toggle to momentary
Replies
5
Views
3K
crutschow
T
Need help checking over schematic for Arduino Nano Audio Sequencer PCB
Replies
6
Views
4K
liamjerr
L
R
  • Question
I need help with a push button...
Replies
11
Views
4K
ZipZapOuch
Z
Need some help for a FM LIFI communication
Replies
1
Views
2K
rjenkinsgb
S
  • Question
Need help with guitar pedal
Replies
7
Views
2K
ZipZapOuch
Menu
Log in
Register
Cookies are required to use this site. You must accept them to continue using the site. Learn more…