| Storm | Posted: 24 Dec 2021, 03:20 AM |
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 Member Posts: 2 Joined: 11-December 21 |
I'm currently trying to make a desk lamp for a friend that plays music when turned on using the code from https://mitxela.com/projects/musical_card. The only problem is I have no idea how to code in assembly, but I'm trying to figure out how to disable the looping in the program, can anyone tell me what I need to change in the code to achieve this? ------------- |
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| mit | Posted: 24 Dec 2021, 10:19 PM |
 yeah whatever Admin Posts: 538 Joined: 4-May 16 |
Greetings. The looping happens when it reaches the end of the music data. The last byte of the data is zero, so when it reads a byte of zero it re-loads the program and starts over. The loadNote routine loads the next byte of data into register r16. On line 124, we have tst r16 (test if r16 is zero) followed by brne (branch if not equal). The code between that and the dontReset label is the re-loading of the music data. Highlighted here: https://github.com/mitxela/ATtiny85-MIDI-player/blob/master/polyphony.asm#L126-L132 If you replace the highlighted lines with a simple hang, such as hang: rjmp hang it should stop playing when it reaches the end of the data. You'd need to reset/power cycle the chip to start it up again. ------------- |
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| Storm | Posted: 25 Dec 2021, 04:39 AM |
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Member Posts: 2 Joined: 11-December 21 |
The help is much appreciated, this is exactly what I was looking for. ------------- |
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