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Forum Index : Microcontroller and PC projects : Issue with "DEVICE LCD CMD" and "DEVICE LCD DATA"
| Author | Message | ||||
| stef123 Newbie  Joined: 25/09/2024 Location: United KingdomPosts: 23 |
Hi, i´m trying to implement a custom Charset for my HD44780-Display, but found a problem. According to my Logic Analyzer, after "DEVICE LCD CMD", issuing "DEVICE LCD DATA", the RS Line is still being held low (CMD), but it has to be high (DATA). Tested V5.08, aswell V6.00. My fault, or a bug? Best regards Stef Edited 2024-11-04 09:45 by stef123 |
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| stef123 Newbie Joined: 25/09/2024 Location: United KingdomPosts: 23 |
Working Solution: External.c, line 2322. " LCD_Byte(j, toupper(*cmdline) == 'D', 0);" to " LCD_Byte(j, toupper(*p) == 'A', 0);" Idk if *cmdline or 'D' was the issue. toupper(*cmdline) =='A' didn´t resolve the problem either. But since i suspect that tupper has to be true (1) in case of "DATA", because it controls eventually the RS Line and 'D' can be found several times in the command string (eg "DEVICE LCD CMD"), i´ve chosen 'A' (=if found, RS=1, if not, RS=0) Maybe not perfect, but i have not much knowledge about C++ behaviour at all. At least it works. Edited 2024-11-04 13:15 by stef123 |
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disco4now Guru  Joined: 18/12/2014 Location: AustraliaPosts: 896 |
I think the line should be LCD_Byte(j, toupper(*lcd) == 'D', 0); lcd is set to point to the first character of DATA or CMD a couple of line above i.e. } else if((p = checkstring(lcd, (unsigned char *)"CMD")) || (p = checkstring(lcd, (unsigned char *)"DATA"))) { // send a command or data Latest F4 Latest H7 |
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| stef123 Newbie Joined: 25/09/2024 Location: United KingdomPosts: 23 |
Thanks ! So correct me if i´m wrong - i´m not into C++ programming at all, i do more Assembler and Basic - if you deliver *cmdline to toupper (idk if it contains the entire command string, i think so), you will always run into a toupper-Flag that is set because it finds the "D" of "Device". That would mean that the Flag/RS line would be always high, but that isn´t the case. But if *cmdline contains the string "LCD" without "DEVICE" , toupper runs into a Flag that is not being set (=RS-Line low) (wrong: Flag=1, RS=High) and doesn´t care about the following "CMD" or "DATA", because it already found the first occurance of "D" in "LCD". What i don´t understand is why *cmdline wouldn´t work together (better: doesn´t give the correct result) for example with toupper "A", but *p with "A". If "DATA" is the key to set the Flag, toupper would find in *cmdline the occurance "A" in "Data" which would be flag=1 = RS=1. Thats the reason why i have chosen "A" (could have been "T" aswell), because "D" occurs in "CMD" aswell in "DATA". As said, idk the contents of *cmdline. Edited 2024-11-04 23:37 by stef123 |
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| matherp Guru Joined: 11/12/2012 Location: United KingdomPosts: 9101 |
Please try V6.00.00RC14 and let me know if it works. NB: in RC14 you can use the LCD command without the DEVICE prefix |
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| stef123 Newbie Joined: 25/09/2024 Location: United KingdomPosts: 23 |
Hi Peter, yup, RC14 works as expected. Thank you! |
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| JohnS Guru Joined: 18/11/2011 Location: United KingdomPosts: 3800 |
deleted - fixed by Peter et al I think John Edited 2024-11-04 23:56 by JohnS |
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