I have been playing with the a nextion display. For this I have been re-imaging an older project which has an audio detection circuit. Original project:- http://www.picaxeforum.co.uk/showthread.php?26768-High-speed-photography
All works fine until the display is dimmed, at which point the signal from the audio detector goes high. I cant actually detect any issues with noise on the power line.
If the display is disconnected from power while dimmed the audio detector returns to normal. if brightness is set to 100, again thing return to normal.
If I have a separate power supply for the audio detector things work normally (wall wart for main circuit, batteries for audio with shared 0v). This is what led me to believe there is some noise on the power line.
There is no change if the display is left powered on and disconnected from the H-serial pins with the analogue inputs connected to ADC 5 and 6 as the project makes use of comparator interrupt.
The circuit is currently being prototyped on an axe091 using a 20x2. I have tried adding an 100nf and 100uf capacitor across the power rails next to where the nextion meets the board which had no affect on the noise causing the issue.
I was hoping to keep component count as low as possible as a result was going to run the system on 3 AA batteries with no regulator.
Although the system will function just fine without the display dimming it wold be better to do so as its intended to be used in near darkness and light emitted from the screen may well affect the final image. The original just hide the display (send 254,8) and then restoring is when needed (254,12).
This is not something that I have had to deal with in the past so am in new territory and any help would be appreciated.
sound detection circuit: http://www.picaxe.com/docs/picaxe_sound.pdf
All works fine until the display is dimmed, at which point the signal from the audio detector goes high. I cant actually detect any issues with noise on the power line.
If the display is disconnected from power while dimmed the audio detector returns to normal. if brightness is set to 100, again thing return to normal.
If I have a separate power supply for the audio detector things work normally (wall wart for main circuit, batteries for audio with shared 0v). This is what led me to believe there is some noise on the power line.
There is no change if the display is left powered on and disconnected from the H-serial pins with the analogue inputs connected to ADC 5 and 6 as the project makes use of comparator interrupt.
The circuit is currently being prototyped on an axe091 using a 20x2. I have tried adding an 100nf and 100uf capacitor across the power rails next to where the nextion meets the board which had no affect on the noise causing the issue.
I was hoping to keep component count as low as possible as a result was going to run the system on 3 AA batteries with no regulator.
Although the system will function just fine without the display dimming it wold be better to do so as its intended to be used in near darkness and light emitted from the screen may well affect the final image. The original just hide the display (send 254,8) and then restoring is when needed (254,12).
This is not something that I have had to deal with in the past so am in new territory and any help would be appreciated.
sound detection circuit: http://www.picaxe.com/docs/picaxe_sound.pdf