| Mauro Carvalho Chehab | 76b5a6e | 2019-07-26 09:51:21 -0300 | [diff] [blame] | 1 | =================================== |
| 2 | cfag12864b LCD Driver Documentation |
| 3 | =================================== |
| 4 | |
| 5 | :License: GPLv2 |
| Miguel Ojeda | c131bd0 | 2021-02-25 17:21:00 -0800 | [diff] [blame^] | 6 | :Author & Maintainer: Miguel Ojeda <ojeda@kernel.org> |
| Mauro Carvalho Chehab | 76b5a6e | 2019-07-26 09:51:21 -0300 | [diff] [blame] | 7 | :Date: 2006-10-27 |
| 8 | |
| 9 | |
| 10 | |
| 11 | .. INDEX |
| 12 | |
| 13 | 1. DRIVER INFORMATION |
| 14 | 2. DEVICE INFORMATION |
| 15 | 3. WIRING |
| 16 | 4. USERSPACE PROGRAMMING |
| 17 | |
| 18 | 1. Driver Information |
| 19 | --------------------- |
| 20 | |
| 21 | This driver supports a cfag12864b LCD. |
| 22 | |
| 23 | |
| 24 | 2. Device Information |
| 25 | --------------------- |
| 26 | |
| 27 | :Manufacturer: Crystalfontz |
| 28 | :Device Name: Crystalfontz 12864b LCD Series |
| 29 | :Device Code: cfag12864b |
| 30 | :Webpage: http://www.crystalfontz.com |
| 31 | :Device Webpage: http://www.crystalfontz.com/products/12864b/ |
| 32 | :Type: LCD (Liquid Crystal Display) |
| 33 | :Width: 128 |
| 34 | :Height: 64 |
| 35 | :Colors: 2 (B/N) |
| 36 | :Controller: ks0108 |
| 37 | :Controllers: 2 |
| 38 | :Pages: 8 each controller |
| 39 | :Addresses: 64 each page |
| 40 | :Data size: 1 byte each address |
| 41 | :Memory size: 2 * 8 * 64 * 1 = 1024 bytes = 1 Kbyte |
| 42 | |
| 43 | |
| 44 | 3. Wiring |
| 45 | --------- |
| 46 | |
| 47 | The cfag12864b LCD Series don't have official wiring. |
| 48 | |
| 49 | The common wiring is done to the parallel port as shown:: |
| 50 | |
| 51 | Parallel Port cfag12864b |
| 52 | |
| 53 | Name Pin# Pin# Name |
| 54 | |
| 55 | Strobe ( 1)------------------------------(17) Enable |
| 56 | Data 0 ( 2)------------------------------( 4) Data 0 |
| 57 | Data 1 ( 3)------------------------------( 5) Data 1 |
| 58 | Data 2 ( 4)------------------------------( 6) Data 2 |
| 59 | Data 3 ( 5)------------------------------( 7) Data 3 |
| 60 | Data 4 ( 6)------------------------------( 8) Data 4 |
| 61 | Data 5 ( 7)------------------------------( 9) Data 5 |
| 62 | Data 6 ( 8)------------------------------(10) Data 6 |
| 63 | Data 7 ( 9)------------------------------(11) Data 7 |
| 64 | (10) [+5v]---( 1) Vdd |
| 65 | (11) [GND]---( 2) Ground |
| 66 | (12) [+5v]---(14) Reset |
| 67 | (13) [GND]---(15) Read / Write |
| 68 | Line (14)------------------------------(13) Controller Select 1 |
| 69 | (15) |
| 70 | Init (16)------------------------------(12) Controller Select 2 |
| 71 | Select (17)------------------------------(16) Data / Instruction |
| 72 | Ground (18)---[GND] [+5v]---(19) LED + |
| 73 | Ground (19)---[GND] |
| 74 | Ground (20)---[GND] E A Values: |
| 75 | Ground (21)---[GND] [GND]---[P1]---(18) Vee - R = Resistor = 22 ohm |
| 76 | Ground (22)---[GND] | - P1 = Preset = 10 Kohm |
| 77 | Ground (23)---[GND] ---- S ------( 3) V0 - P2 = Preset = 1 Kohm |
| 78 | Ground (24)---[GND] | | |
| 79 | Ground (25)---[GND] [GND]---[P2]---[R]---(20) LED - |
| 80 | |
| 81 | |
| 82 | 4. Userspace Programming |
| 83 | ------------------------ |
| 84 | |
| 85 | The cfag12864bfb describes a framebuffer device (/dev/fbX). |
| 86 | |
| 87 | It has a size of 1024 bytes = 1 Kbyte. |
| 88 | Each bit represents one pixel. If the bit is high, the pixel will |
| 89 | turn on. If the pixel is low, the pixel will turn off. |
| 90 | |
| 91 | You can use the framebuffer as a file: fopen, fwrite, fclose... |
| 92 | Although the LCD won't get updated until the next refresh time arrives. |
| 93 | |
| 94 | Also, you can mmap the framebuffer: open & mmap, munmap & close... |
| 95 | which is the best option for most uses. |
| 96 | |
| 97 | Check samples/auxdisplay/cfag12864b-example.c |
| 98 | for a real working userspace complete program with usage examples. |