LED C1 builds up until bright

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JardiniM
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LED C1 builds up until bright

Postby JardiniM » Tue Jan 02, 2018 7:37 pm

I'm running the LED example (AN00175) for the startKit and after some time (few seconds) the LED C1 keep bright all the time.

I left the board unplugged for a few minutes and them plug it on USB again. The LED C1 slowly build up until get bright, again, after a few seconds.

Anyone else having the same problem? I have found the same effect on other examples, even if they not touch the LED C1.

Can it be some PCB problem?

Thanks in advance.
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mon2
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Postby mon2 » Wed Jan 03, 2018 10:26 am

Hello. Did you alter any part of the source code from this example? Try to erase the flash so the factory code runs from the internal ROM. The factory rom code is also a breathing led demo but believe all 3x3 leds will do this effect - off to bright and then repeat. Try the other led example, spinning leds and post your results.
JardiniM
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Joined: Tue Jan 02, 2018 7:23 pm

Postby JardiniM » Wed Jan 03, 2018 10:57 am

Hello mon2.

Yep. I've tried the other LED examples AN00174, AN00175 without any alteration on the source and also tested with the factory default breathing. LED C1 always build up slowly until almost bright.

The other functions work as intended, in ex. slider X and Y change the bright and the speed accordingly and the button change the pattern (except C1, who never fall bellow almost bright after a few seconds)
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mon2
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Postby mon2 » Wed Jan 03, 2018 2:02 pm

That is strange. In the source code locate the port pin linked to led C1 and remove from the equation. The startkit hardware manual has the schematics for your reference. Does this stop C1? Perhaps an assembly fault of the pcb? Is this kit new? Always behaved like this?
JardiniM
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Posts: 3
Joined: Tue Jan 02, 2018 7:23 pm

Postby JardiniM » Wed Jan 03, 2018 2:19 pm

I'll try a 'blank' firmware later after the work.

The kit is new, I've bought it three months ago, but only now, with the holidays I had time to toy with it.

I program for desktop and sometimes for firmware for some time now and I want to learn how to program fpga (verilog, vhdl) and xTime. I've also been a technician in electronics, I'm rusty, but I'm slowly coming back :)
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mon2
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Postby mon2 » Wed Jan 03, 2018 4:58 pm

Very nice. Personally prefer Verilog and used the following website to learn a great deal:

http://www.fpga4fun.com/

Jean (who runs the website) is brilliant and very responsive to questions. Recommend that you pickup one of the many low cost kits from Lattice Semiconductor that will be then linked to a free license to allow you to test the FPGA products. They offer some very low cost FPGA devices to move forward.

XMOS is like a FPGA but in the end, perhaps easier to use since you are working in C. There are some learning curves ahead but can be as simple or complex as your would like. The XMOS devices are like having virtual 4 / 8 microcontrollers in a single TILE so each such micro can run independently from the other. You can order multi-tile versions of the parts. Your specific startkit is a dual tile system but one tile is for the USB interface so you are left with 8 virtual processors for your experiments.

There are many public pieces of IP for the XMOS devices to get you started. Have fun.

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