It is currently Thu Jul 27, 2017 9:03 am

All times are UTC




Post new topic Reply to topic  [ 11 posts ] 
Author Message
PostPosted: Tue May 16, 2017 8:08 am 
Offline
Member
Member

Joined: Tue May 16, 2017 7:06 am
Posts: 6
(i'm french and not electronic specialist, sorry)

Hi,

I've just assembled a K8095 kit. As Conrad(.fr) doesn't sell anymore the official LCD display option, I get another (very big) LCD display and make my own adapter.
I used a "LCD Anag Vision AV1621YRB-SJ" with the following mapping :
Code:
J10 -> LCD
1->1
2->2
3->3
4->4
5->5
6->6
7->11
8->12
9->13
10->14

I successfully wire all wires on LCD display except A & K for display's LED. I found 9.6v on A&K on J10.
Note : LD4 power led indicator is soldered

The LCD need for LED is :
LED Forward Voltage Vf 25 °C - - - Typical : 4.2 / Max : 4.6 V
LED Forward Current If 25 °C - - - Typical : 260 / Max : 420 mA
LED weiß (white in german?) Voltage* ILED 3.5 V Min : 50 / Typical : 60 / Max : 75 mA

Can I found correct current somewhere on the K8095 PCB ?

Image
Image

My YouTube timelapse :


Thanks a lot,
Simon


Last edited by sim_v on Wed May 17, 2017 8:05 am, edited 6 times in total.

Top
 Profile  
 
PostPosted: Tue May 16, 2017 1:45 pm 
Offline
Member
Member

Joined: Tue May 16, 2017 7:06 am
Posts: 6
Is it normal that I have 9.6V between pin LED_A & LED_K of J10 connector (and not 12v) ?
(I've put LD4 on the PCB)

In case of 9.6v, a 22 ohms resistor in serial on Anode will be fine ?
In case of 12v, a 32 ohms resistor in serial on Anode will be fine ?

Image


Top
 Profile  
 
PostPosted: Wed May 17, 2017 8:25 am 
Offline
User avatar
Velleman Support
Velleman Support

Joined: Mon Dec 11, 2006 12:03 pm
Posts: 4922
Location: Belgium
Thanks for nice video :)
Quote:
Is it normal that I have 9.6V between pin LED_A & LED_K of J10 connector (and not 12v) ?
This is OK. The rest of the voltage is left over the transistor T1 and resistor R9.
Quote:
In case of 9.6v, a 22 ohms resistor in serial on Anode will be fine ?
In case of 12v, a 32 ohms resistor in serial on Anode will be fine ?
There is no need for additional resistor. Transistor T1 (togethrt with R9) limits the LED current to about 26mA.


Top
 Profile  
 
PostPosted: Wed May 17, 2017 12:51 pm 
Offline
Member
Member

Joined: Tue May 16, 2017 7:06 am
Posts: 6
Thanks, I had no light with a direct connection (I tried after some tests with a standard green LED).
What is the current needed of my display 260mA (Ic) or 60mA (iled) ? Maybe my LCD display needs too much power...


Top
 Profile  
 
PostPosted: Wed May 17, 2017 2:08 pm 
Offline
User avatar
Velleman Support
Velleman Support

Joined: Mon Dec 11, 2006 12:03 pm
Posts: 4922
Location: Belgium
Indeed, maybe the current is too low. Have you measured the backlight LED current?
You may also test the backlight with adjustable power supply and a series resistor...


Top
 Profile  
 
PostPosted: Sun May 28, 2017 7:59 pm 
Offline
Member
Member

Joined: Tue May 16, 2017 7:06 am
Posts: 6
I've got a solution for the first LCD : no lighting !

I've buy a second K8095 kit and another LCD display (with light).
But LCD display only half of the screen. In fact the 8 characters on the left and on the 2 lines have a very low contrast.

1234567890ABCDEF
1234567890ABCDEF

I switch displays of the 2 kits . . . and now the 2 kits display half of the characters.
I thinking frying the LCD display with a incorrect connection but a test with an Arduino show characters on the full display even if left part is a little bit dimmer.
On the LCD slot (with LCD plug in), I have 4.68V between pin 0 and 1. (4.96v before the D1 diode)
On the LCD slot (without LCD), I have 7.60V between pin 0 and 1.
On the LCD slot, I have 0.04mV between pin 0 and 2 (contrast if full).
3.29v between GND and VDD
3.29v between GND and VPP

First display (the one that was on previous post) : on arduino = full display
Image
First display (the one that was on previous post) : on both K8095 = half display
Image

Second display (the new one) : on both K8095 = half display
Second display (the new one) : on arduino = full display
Image

LCD power on K8095 seems very low . . .


Top
 Profile  
 
PostPosted: Mon May 29, 2017 8:56 pm 
Offline
User avatar
Velleman Support
Velleman Support

Joined: Mon Dec 11, 2006 12:03 pm
Posts: 4922
Location: Belgium
Strange problem indeed.
In your first post the external display works OK.
What has changed?


Top
 Profile  
 
PostPosted: Mon May 29, 2017 9:28 pm 
Offline
Member
Member

Joined: Tue May 16, 2017 7:06 am
Posts: 6
I just swap displays from kit 1 and 2 and do nothing else on the first kit.


Top
 Profile  
 
PostPosted: Wed May 31, 2017 7:17 am 
Offline
User avatar
Velleman Support
Velleman Support

Joined: Mon Dec 11, 2006 12:03 pm
Posts: 4922
Location: Belgium
OK
Normally the K8095 should work with any standard 16x2 display having Hitachi compatible LCD controller.
Here seems to be a picture of one such example:
https://www.quasarelectronics.co.uk/Ite ... player-kit


Top
 Profile  
 
PostPosted: Mon Jun 19, 2017 9:53 am 
Offline
Member
Member

Joined: Tue May 16, 2017 7:06 am
Posts: 6
kits work with new displays. Old displays work with arduino-s.


Top
 Profile  
 
PostPosted: Mon Jun 19, 2017 11:23 am 
Offline
User avatar
Velleman Support
Velleman Support

Joined: Mon Dec 11, 2006 12:03 pm
Posts: 4922
Location: Belgium
It's nice that you have found compatible displays for the K8095.


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 11 posts ] 

All times are UTC


Who is online

Users browsing this forum: No registered users and 2 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum

Search for:
Jump to:  
Powered by phpBB® Forum Software © phpBB Group