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electronic:lcd:metp0000 [2018/11/23 09:04] – tonyelectronic:lcd:metp0000 [2026/09/26 05:12] (current) – tony
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-{{ :electronic:lcd:pa101844a.jpg?200|METP0000}} +{{ :electronic:lcd::pa101833a.jpg?200|METP0000}} 
-^<html><p style="text-align:center">LCD Description</p></html>||+^  LCD Description  ||
 ^Model|**METP0000**| ^Model|**METP0000**|
 ^Manufacturer|Mettler  Toledo| ^Manufacturer|Mettler  Toledo|
-^Recovered from|Mettler  Toledo  Model  8217 scale |+^Recovered from|Mettler  Toledo  Model  8217 weigh scale|
 ^Board IDs|OPCVO, METP0000 REV B| ^Board IDs|OPCVO, METP0000 REV B|
 ^LCD type|positive| ^LCD type|positive|
 ^Polarizer type|reflective| ^Polarizer type|reflective|
-^Columns|6|+^Columns|6 ((a 7th, undisplayed, digit is used to control some of the under-bar elements))|
 ^Rows|1| ^Rows|1|
-^Char matrix|7 segment with underscore, decimal point and comma| +^Char matrix|7 segment with decimal point and comma, plus 5 under-bar elements| 
-^Driver IC|NEC μPD7225 (({{:electronic:datasheet:nec:upd7225.pdf}})) (({{electronic:datasheet:nec:upd7225_ap_note.pdf}}))|+^Driver IC|NEC D7225GB (μPD7225)  (({{:electronic:datasheet:nec:upd7225.pdf}})) (({{electronic:datasheet:nec:upd7225_ap_note.pdf}})) (({{https://ia801305.us.archive.org/4/items/bitsavers_necdatabooMicrocontrollerDataBook_57118308/1990_NEC_Single-Chip_Microcontroller_Data_Book.pdf|NEC 1990 Microcontroller Databook, page #826}}))|
 ^Backlight|-| ^Backlight|-|
-^Arduino driver||+^Arduino driver|[[:arduino:metp0000_driver_library|METP0000 driver library]]|
 ^Connector|RJ45| ^Connector|RJ45|
 ^Num Pins|8| ^Num Pins|8|
 ^Pin spacing| | ^Pin spacing| |
  
-^ ^^^^Arduino test rig ((reminder for my personal testing, not useful for anyone else!))||+^  Connector pin-out  ^^^^  Arduino test rig ((colour coding of wires in a re-purposed ethernet cable))  ||
 ^Pin#^Label^IC pin^Label^Pin^colour| ^Pin#^Label^IC pin^Label^Pin^colour|
-^1|Busy| |~Busy|-|white/orange| +^1|Busy| |~Busy|D10 ((optional when using Arduino driver library))|white/orange| 
-^2|Reset| |~Reset|D7|orange|+^2|Reset| |~Reset|D7 ((not needed by Arduino driver library))|orange|
 ^3|Si| |Si|D5|white/green| ^3|Si| |Si|D5|white/green|
 ^4|SClk| |~SCK|D4|blue| ^4|SClk| |~SCK|D4|blue|
 ^5|CS| |~CS|D8|white/blue| ^5|CS| |~CS|D8|white/blue|
-^6|~C/D| |C/~D|D6|green|+^6|~C/D| |C/~D|D6 ((not needed by Arduino driver library))|green|
 ^7|GND|20|Vss|GND|white/brown| ^7|GND|20|Vss|GND|white/brown|
 ^8|+5V|21|Vdd|+5V|brown| ^8|+5V|21|Vdd|+5V|brown|
 \\ \\
 +
 \\ \\
- 
-R1 across the cl1/cl2 clock generation pins is 200kΩ - nominally about 120kHz clock.\\ 
-Resistor ladder wired for 1/3 bias across the Vlc1,2,3 pins.    COM3 appears to be unconnected, which implies a 3-time sharing type of LCD (using COM0,1,2).\\ 
-Some testing was done with mode byte set to 0x48 (=  1/3 bias method,  divide-by-3 time division drive , and a frequency division ratio of 1/2^7  (frame frequency=fCL /(2^7 × 3)).\\ 
-Digits are 7 segment plus decimal point and comma on the 2nd through 6th character (from left to right), plus 5 "underscore" characters evenly spaced below the line of digits.  The decimal point to the right, and the comma to the left of each digit appear to be one unit, except for the first and last digits.  For the first digit an underscore replaces the decimal point element.  And for the last digit, an underscore replaces the comma element.\\ 
-But all segments couldn't be addressed, 3 of the underscores may be implemented as segments of extra characters (ie 7th and 8th digits??), and segment "f" and "c" weren't conrolled by 8 bit words. 
-There are 10 individual elements to each character - 7 segment digits plus decimal point, comma and underscore.  But the underscores are actually repurposed commas and decimal points on the first and last characters.  The other three underscores may be addressed as part of 3 phantom characters not otherwise displayed. 
- 
-(On my example board the 4th digit didn't appear to be responding properly, possibly bad connections) 
- 
-Data and control lines are buffered by inverting schmitt triggers (74hc14), so the driver software needs to invert all those signals. 
- 
-The front keypad switches appear to be encoded by a 74HC165 shift register and wire-ORed to the pin 1 output line (also used as the the µPD7225 busy line). 
 ---- ----
-===== Examples : ===== +===== Examples =====
- +
-{{:electronic:lcd:pa101844a.jpg?800|METP0000}}+
  
 {{:electronic:lcd:pa101833a.jpg?800|METP0000}} {{:electronic:lcd:pa101833a.jpg?800|METP0000}}
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 {{:electronic:lcd:pb222808a.jpg?800|METP0000}} {{:electronic:lcd:pb222808a.jpg?800|METP0000}}
-\\ 
-\\ 
-Segments/elements associated with each digit:\\ 
-{{:electronic:lcd:metp0000_segments.png?400|METP0000}} 
  
 +{{:electronic:lcd:pb222808b.jpg?200|METP0000}}

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electronic/lcd/metp0000.1542963860.txt.gz · Last modified: 2018/11/23 09:04 by tony
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