![]() ![]() Though I think there is a hardware walkaround If LCD had something like software reset it could help but I did not find anything in datasheet. If you reset your MCU board while your LCD is writing something without cutting off power, LCD may get first nibble but lose the second 4bit nibble and interprets your initialize data as second nibble data to show on LCD and simply get confused.To cope with that you have to put a delay between your packet. when using a fast microcontroller (180 MHz clock), if you send I2C packet consecutive LCD may not be that fast to understand it and as James said in other post LCD may lose some packet and get confused.I experienced this while using a STM32f429 discovery board, and I found out there are two reasons that this happens. If you have an oscilloscope, check if your I2C signals are clean and have full swing. Look at it under a bright light, using a binocular parts-examination microscope if you've got one, and see if there are loose solder particles, extra solder flux, or loose solder connections on that board. If your mis-specification of display size (20, 4 vs 16, 2) isn't responsible for the problem, then maybe there is a hardware problem with the backpack you've soldered on to the LCD. Note, a space is 0x20, and the reverse of that is 0x02, which would access a character from the character-generator RAM, which will contain random bits and produce a random blob as in your picture. It appears that the high nibble of what you sent is being used as the low nibble of what is displayed, and the low nibble is being used as the high, but with some bits sometimes going wrong. Same case with $: the preceding subpattern should match right at the end of the string.īut it's also include the spaces and counted as strange character so what to do:-īy removing the anchors, and the quantifier *.If you look up the ASCII codes for what you sent vs what was displayed, and also look at "Table 4 Correspondence between Character Codes and Character Patterns (ROM Code: A00)" in an HD44780U spec sheet, you will find hexadecimal values like the following. ![]() When using ^ the regex engine checks if the next subpattern appears right at the start of the string (or line if /m modifier is declared in the regex). The anchors (like ^ start of string/line, $ end of string/line and \b word boundaries) can restrict matches at specific places in a string. ") document.write(format.test("MyStringContainingNoSpecialChars")) ") document.write(format.test("My string with spaces") " Ive tried to write another RegExpr and use the. Regex = /|||||||\u203B/g Īnd it worked for me and I started to understand the issue ,but what if u want to check the other languages like Chinese, Deutsche, Russian …….etc So I wanted to do a quick a check if my text include Japanese characters and i ended up using this code. ![]() In the beginning I tried to check the css and played around to find a css solution that supports all browsers and i thought it might be a font issue, then i realised that i need to do some changes on the code, so i decided i should check if the text has this weird cases(alphabets) or not. I've got a bug ticket from our QA says that the text style doesn't display as it should be when the language is Japanese. So how to know if ur text have strange characters or not ?
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