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| electronic:lcd:metp0000 [2018/12/01 08:38] – tony | electronic:lcd:metp0000 [2026/09/26 05:12] (current) – tony | ||
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| {{ : | {{ : | ||
| - | ^< | + | ^ LCD Description |
| ^Model|**METP0000**| | ^Model|**METP0000**| | ||
| ^Manufacturer|Mettler | ^Manufacturer|Mettler | ||
| Line 10: | Line 10: | ||
| ^Rows|1| | ^Rows|1| | ||
| ^Char matrix|7 segment with decimal point and comma, plus 5 under-bar elements| | ^Char matrix|7 segment with decimal point and comma, plus 5 under-bar elements| | ||
| - | ^Driver IC|NEC D7225GB (μPD7225) | + | ^Driver IC|NEC D7225GB (μPD7225) |
| ^Backlight|-| | ^Backlight|-| | ||
| ^Arduino driver|[[: | ^Arduino driver|[[: | ||
| Line 17: | Line 17: | ||
| ^Pin spacing| | | ^Pin spacing| | | ||
| - | ^ ^^^^Arduino test rig ((colour coding of wires in a re-purposed ethernet cable))|| | + | ^ |
| ^Pin# | ^Pin# | ||
| - | ^1|Busy| |~Busy|-|white/ | + | ^1|Busy| |~Busy|D10 ((optional when using Arduino driver library))|white/ |
| - | ^2|Reset| |~Reset|D7|orange| | + | ^2|Reset| |~Reset|D7 |
| ^3|Si| |Si|D5|white/ | ^3|Si| |Si|D5|white/ | ||
| ^4|SClk| |~SCK|D4|blue| | ^4|SClk| |~SCK|D4|blue| | ||
| ^5|CS| |~CS|D8|white/ | ^5|CS| |~CS|D8|white/ | ||
| - | ^6|~C/D| |C/ | + | ^6|~C/D| |C/ |
| ^7|GND|20|Vss|GND|white/ | ^7|GND|20|Vss|GND|white/ | ||
| ^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, | ||
| - | Testing was done with mode byte set to 0x48 (= 1/3 bias method, | ||
| - | The display consists of six digits. Each digit is made up of 7 segments plus a decimal point and comma on the 2nd through 6th digit (from left to right), plus 5 " | ||
| - | So although there seems to be 10 individual elements to each character - 7 segments plus decimal point, comma and underscore, infact there are only 9 different addressable elements, the underscores are actually either repurposed commas and decimal points (as in the first and last characters) or addressed as segments of a seventh, undisplayed, | ||
| - | See the illustration below. | ||
| - | |||
| - | 9 segments can't be addressed through normal writing of 8 bit bytes to the display buffer as 9 bits are needed. | ||
| - | |||
| - | (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/metp0000.1543653519.txt.gz · Last modified: 2018/12/01 08:38 by tony
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