STM CircleOS forum / Primer2 Troubles: Testing Output of 2.8 Volt Supply

tybeede · 2008-12-24 03:13:15

Here are the results of the testing I was able to squeeze into today. I took a look at the output from the U9 regulator. To my understanding it is a step down reg which should be providing the 2.8 volts to the main digital side of the Primer2. I think the speaker and the backlight are powered from a higher voltage source. With the Primer2 plugged into my computer I measured 0.1707V. Looks like the U9 may be the source of my problems. I also checked the battery and it measured 4.2V so it must be fully charged. I'm assuming I can work around this with some combination hot air, green wire, solder wick, and some free time. Let me know what you guys think and any results from your own testing at home/work.

Circuit In Question:

Regulator Datasheet:
http://www.stm32circle.com/projects/fil … L6928D.pdf

Gerber View of Circuit Board to Locate U9 and C20:

Testing Voltage Across C20:

Close Up View:

Francis · 2008-12-24 10:39:41

For the last days, we are encountering two different issues:
1. Some users reload the CircleOS binary code of the Primer1, that is NOT working for Primer2 and shuts down immedialtely the power supply.
2. At the factory (until now, no end user reports this problem), testers meets a problem with about 2% of the boards, because of the U9 regulator. The problem seems to be caused by a too light link between the GND pin of U9 and the ground copper. The factory is currently testing a solution (a wire soldered manually), but they have also to replace the burned regulators ..

For the #1, the behaviour is the following: sometimes the LCD monitor lights on, then off immediately. The solution consists in reprogramming the CircleOS for Primer2 ( Restore_Primer2_Circle_Factory.bat) while keeping pressed the button to maintain the power supply.

tybeede · 2008-12-26 05:15:29

Great, the factory software reset did the trick. Thanks a bunch for the help.

tybeede · 2009-01-02 06:01:55

taking a look at the schematics it looks like my U9 test wasn't even valid. The push button appears to be tied into a power transistor which provides the current to the reg.

Francis · 2009-01-02 10:01:37

Yes the problem is that, when the Primer1 firmware is loaded on the Primer2, it powers off the board at the initialization stage (different pinout...). It's why you need to push on the button to force the command of the switch.

samarkh · 2009-01-11 13:46:25

Hi
For what it is worth I to needed to run this file, ( Restore_Primer2_Circle_Factory.bat) which is located in <ride installed path>\Lib\ARM\CircleOS to get my Primer2 to work!
Yours Simon M.

Francis · 2009-01-11 14:15:37

We will publish early next week the new release of CircleOS. One of the bew feature is the detection of the hardware as the very intialization step. Therefore, the problem described above will not occur anymore.

# 1 2008-12-24 03:13:15 Primer2 Troubles: Testing Output of 2.8 Volt Supply - U9 regulator

Primer2 Troubles: Testing Output of 2.8 Volt Supply - U9 regulator

# 2 2008-12-24 10:39:41 Primer2 Troubles: Testing Output of 2.8 Volt Supply - U9 regulator

Re: Primer2 Troubles: Testing Output of 2.8 Volt Supply - U9 regulator

# 3 2008-12-26 05:15:29 Primer2 Troubles: Testing Output of 2.8 Volt Supply - U9 regulator

Re: Primer2 Troubles: Testing Output of 2.8 Volt Supply - U9 regulator

# 4 2009-01-02 06:01:55 Primer2 Troubles: Testing Output of 2.8 Volt Supply - U9 regulator

Re: Primer2 Troubles: Testing Output of 2.8 Volt Supply - U9 regulator

# 5 2009-01-02 10:01:37 Primer2 Troubles: Testing Output of 2.8 Volt Supply - U9 regulator

Re: Primer2 Troubles: Testing Output of 2.8 Volt Supply - U9 regulator

# 6 2009-01-11 13:46:25 Primer2 Troubles: Testing Output of 2.8 Volt Supply - U9 regulator

Re: Primer2 Troubles: Testing Output of 2.8 Volt Supply - U9 regulator

# 7 2009-01-11 14:15:37 Primer2 Troubles: Testing Output of 2.8 Volt Supply - U9 regulator

Re: Primer2 Troubles: Testing Output of 2.8 Volt Supply - U9 regulator

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