ChibiOS Free Embedded RTOS

Hello Everyone,

I am working on the 2.6 FATFS for F103R Example.

My Code Utilizes Serial 1,2 UART3, SPI2, ADC1 and a few GPIOs. Serial1 is a GPS Modem, Serial2 is the console output for debugging, UART3 is a WiFi modem.

Once I Erase the Chip and Flash My code it works fine ( ST-LINKV2).

Once the Board is powered on, one UART3 Peripheral doesn't work fine. It does 2 operations and then doesn't respond to anything.

Weird issue is, if i Connect the board to a Laptop ( UART2 TX RX and GND), the board works fine after Power off and Power of, but if i disconnect the Laptop, it doesn't work.

Now, If i power the board up, press the reset button, it works fine.

I've check all connections, regulator outputs, everything is in the fine range, no fluctuations, no interference what-so-ever.

Anyone has had this issue before? Where you need to Press the Reset Button after the board is powered on to get the code to work properly?

Could it relate to the rise time of your power supply? Can you (at least temporarily) add a switch so that your power supply is definitely at 3.3V before applying it to the processor?

Could be a missing ground/0V connection which the laptop might supply.

Bad joint on the components providing the power up reset circuit on your board.

Are you loading code/data in RAM using the debugger? it would not be there after a cold reset.

Giovanni

Thanks for the Tips,



I am doing this after checking if the microcontroller has been on for less than 1sec.

I know this is ugly and crude and what not, but i am in another country testing the setup. and if i don't get this working, i'l be fed to the lions for sure

JK,

Cheers

How about the BOOTx pins? Are they at the right levels?

Do you have a capacitor on the reset pin?

This is needed to let the power stabilize before the mcu turns on.