John_W._Couvillon

LPC17 - Red LED on the LPC pcb is cycling on and off

6 posts in this topic

The  red LED on the LPC pcb is cycling on and off, slowly building up to bright, then fades away.  the LED cycles much like the led on a USB flash drive. The LED is much brighter then normal at its brightest

 The LPC has midio128ver3 loaded and appears to be functioning normally, with exception of the LED.

This began when a USB cable was plugged into the USB connector on the pcb to view the DI settings with mios studio. The unit was energized, receiving power from a 6vdc supply (J1), and the jumper on the PCB (J22)was removed to isolate from the USB power source.  The usb cable was removed, jumper inserted and the unit reconnected to the 6vdc supply, and the LED still cycles.

Is it a NO, NO to do the above, and is there a way to recover?

Johnc

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It works like intended.

The flashing LED with PWM modulated fading effect is a sign of life (application still running)

 

Best Regards, Thorsten.

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I hope that I explained the situation commpletely.

The LED has always blinked and stayed on especially when first energized, but it has never been this bright and pulsing on and off. This behavior began when i plugged in the USB cable to use mios studio.  The LPC has been operating along time with a core 8 on a common power supply, so the jumper isolating the system from usb/computer power was removed. 

since the incident,  returning to USB power with the jumper in place does not solve the problem. 

Also, the reason I was using mios studio was to load the recorder/player fix that you (TK) provided to correct some code issue involving matricies.  the "fix"  did get the recorder working (I thought), but all of a sudden,  strange loud fixed pitch sounds came through that are not related to the material being played back.  I had to pull the power to the LPC to clear the noise. Now I question the "fix"!

Johnc

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I'm lost, please help me!

 

I'm unsure if we are speaking about the same behaviour, resp. if you've misinterpreted a change in the firmware and therefore come to this conclusion, or if we are talking about an actual issue (which is unknown to me).

 

I changed the behaviour of the status LED with V3.019 - if you've used an older version before, the LED was dimmed (not so bright like with newer versions), and not fading/cycling.

 

Best Regards, Thorsten.

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TK,

No, you are not lost.  I was not aware that the behavior of the status LED had changed with ver. V3.019.  That explains the situatiion most adequately.

Thanks,

johnc

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Hi John,

 

I'm relieved that there is a plausible explanation for this behaviour. :smile:

 

Best Regards, Thorsten.

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