April 20, 2024, 06:18:16 AM

Olimexino STM32 GPIO 5V tolerant pins?

Started by olimexinostm32tester, May 08, 2013, 02:03:20 AM

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olimexinostm32tester

Dear all,

are there any 5V tolerant GPIO pins on the Olimexino STM32 board?

I only found this documentation for the Maple board, but would like to verify if the 5V tolerance is the same for the Olimexino STM32 board:
http://leaflabs.com/docs/hardware/maple.html#maple-gpios

Thanks in advance!

LubOlimex

Hey there,

The easiest way to find about 5V tolerant pins in the processor's datasheet: http://www.st.com/web/en/resource/technical/document/datasheet/CD00161566.pdf. On page 28 there is a table with the PINs as fifth column (note the processor's package is LQFP64, so look under this column) and another column named "I/O level". If there is "FT" value in the "I/O level" box then the corresponding pin is 5V compatible.

Best regards,
Lub/OLIMEX
Technical support and documentation manager at Olimex

olimexinostm32tester

Perfect, thank you Lub!

If I understand correctly, this means that only pins above Pin 29 (corresponding to D29) are 5V tolerant. Thus, none of the pins accessible via CON2-4 (D0-20) on the Olimexino Board is 5V tolerant, right?

Then I'm afraid I successfully broke my board. The bootloader still works, but it seems that I can't apply a voltage to e.g. an LED connected to D0. The maple example worked before, so I assume my hardware is broken.

Which test would you suggest to verify wether the board is still operating normally?

All the best,

Peter/olimexinostm32tester

LubOlimex

Hey Peter,

QuoteIf I understand correctly, this means that only pins above Pin 29 (corresponding to D29) are 5V tolerant. Thus, none of the pins accessible via CON2-4 (D0-20) on the Olimexino Board is 5V tolerant, right?
Yes, exactly. But we have provided them on the extension connector named EXT.

Is it possible to connect and control the LED on D2 or D5 instead on D0 just for the test. I think there is some RX on the D0.

The other easier hardware test is with a multimeter. Check if there are 3V3 between power connector pin 2 (3V3) and GND.

Best regards,
Lub/OLIMEX
Technical support and documentation manager at Olimex

olimexinostm32tester

Dear Lub,

thank you for your quick and competent support.

I still don't fully understand, but when connecting the Board to my Win XP Notebook via USB, it won't be recognized as a Maple R3 and even setting it to repetitive Bootloader Mode doesn't allow me to upload a sketch and set a pin to HIGH on the Windows machine.

No I've done this on a MacBook Air and it works! It still doesn't recognize the Maple as a serial device at first, but after uploading a sketch in the repetitive Bootloader mode, it becomes accessible. Any suggestions on what I might do wrong are appreciated. For the time being, I'll program the board via a MacBook, then.

Most important, though: My board works fine, even though I might have given it some 5V TTL pulses on pins that are not 5V tolerant.

Keep up the good work!

Peter