2016-01-12 06:40 AM
Hi,
First of all sorry for bad English.I had designed a PCB for STM32F103 micro-controller for my specific job. The thing is micro-controller works fine when J-link is connected. J-link programmed micro with no error and software runs fine but when i switch the supply with my own 3.3v source and remove J-link, the micro wont start at all . I suspected my power supply which is LM2576-3.3 and tried another sources but micro wont work with any external voltage source with 3.3V. the strange thing is micro work with any external supply with 2.5V output. In datasheet says micro will work with supply voltage 2 to 3.6 but sadly in my PCB micro works with 2.5. Am I missing something? I would appreciate any help. I attached my schematic too.Thanks2016-01-12 06:50 AM
Boot0 should be grounded
2016-01-12 06:54 AM
As you can see in schematic BOOT0 is in junction and in programming time i connect it to vcc and for running time i change jumper to ground connection.
Always After programming i change BOOT0 junction and i connect it to ground .2016-01-12 08:12 AM
In your schematics BOOT0 in pulled up by R11, which forms a voltage divider with R14. So BOOT0 is high and your MCU doesn't boot.
2016-01-12 08:13 AM
You have TWO resistors tied to BOOT0, remove the one pulled to VCC, otherwise your one by the jumper is going to half the voltage when pulled to ground, and will still be above VIL
2016-01-12 11:47 PM