From owner-freebsd-hardware Sun Nov 26 9: 6:44 2000 Delivered-To: freebsd-hardware@freebsd.org Received: from osiris.ipform.ru (osiris.ipform.ru [212.158.165.98]) by hub.freebsd.org (Postfix) with ESMTP id 4687837B479 for ; Sun, 26 Nov 2000 09:06:38 -0800 (PST) Received: from wp2 (wp2 [192.168.0.12]) by osiris.ipform.ru (8.11.1/8.11.1) with SMTP id eAQH6TU90590 for ; Sun, 26 Nov 2000 20:06:30 +0300 (MSK) (envelope-from matrix@ipform.ru) Message-ID: <000701c057cb$38b15fe0$0c00a8c0@ipform.ru> From: "Artem Koutchine" To: Subject: LCD contrast control on extanded temperature lcds Date: Sun, 26 Nov 2000 20:06:28 +0300 Organization: IP Form MIME-Version: 1.0 Content-Type: text/plain; charset="koi8-r" Content-Transfer-Encoding: 7bit X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 5.00.2919.6600 X-MimeOLE: Produced By Microsoft MimeOLE V5.00.2919.6600 Sender: owner-freebsd-hardware@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org Hi! I have managed to attach LCD (HD44780 compatible from Powertip. PC2004-B model). However, the contrast is too bad and i cannot even start developing software to control it the way it need. (super quite home mp3 player, tired of working fans :)). It is an extended tempretaure unit (-20C - 75C) and it needs voltage from GND to -7V on Vo (contrast control pin). I cannot figure out how to get -7V from pc power supply. The other thing, is that LED backlight is heating badly. I thought it has resistor built-in, but it seems as it does not. What resistor should i use there for +5V line (typical current for the LED is 260mA). I hope, someone whould help, because i am a programmer and not very good at MAKING hardware. Regards, Artem To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hardware" in the body of the message