Re: I2C for STM32F3

Yannis Damigos

On Thu, Oct 12, 2017 at 3:52 PM, Wagenknecht, Daniel <Daniel.Wagenknecht@...> wrote:



I’m working on a project that needs I2C functionality on a STM32F0 Chip. Since STM32F0 support is not yet merged into zephyr (I’m observing, I started working with a stm32f3_disco board, which I had available and which uses the same I2C driver (stm32-i2c-v2), with only minor differences (F0 has a combined Event/Error Interrupt, F3 splits both up). I also took a look at the disco_l475_iot1 board for inspiration, because I2C support in Zephyr for this board is implemented and it uses the stm32-i2c-v2 driver as well, but I don’t have one of those boards to test with.


Just a little note before I explain the issues I’m running into on the stm32f3_disco: I basically did the same steps on stm32f4_disco board (which uses the stm32-i2c-v1 I2C driver) and got the  I2C bus working there.

I’m confident, that the basic procedure for adding I2C support to a STM32Fx based board is OK, since I got it working on the stm32f4_disco board this way.


Back to stm32f3_disco. See attachment for the changes I did to the repo based on zephyr-v1.9.0 release.

I’ve got it compiling with samples/drivers/i2c_fujitsu_fram example with a minor change and an I2C dummy device that acts like the fujitsu-fram (test-setup worked well with stm32f4_disco).


diff --git a/samples/drivers/i2c_fujitsu_fram/src/main.c b/samples/drivers/i2c_fujitsu_fram/src/main.c


@@ -13,5 +13,1 @@

-#if defined(CONFIG_SOC_QUARK_SE_C1000_SS)



-#define I2C_DEV CONFIG_I2C_0_NAME


+#define I2C_DEV "I2C_1"


After flashing it onto the stm32f3_disco board the I2C Pins (PB8, PB9) are high with pull-up (like intended), but nothing is happening on the bus. When I single step through  the code with the debugger I loose connection in

file drivers/i2c/i2c_ll_stm32_v2.c

function  msg_init(…)

line 41


Last step I can do is out of the LL_I2C_SetSlaveAddr(..) function. The debugger fails with the following message:


Error: jtag status contains invalid mode value - communication failure

Polling target stm32f3x.cpu failed, trying to reexamine

Examination failed, GDB will be halted. Polling again in 100ms


To reconnect to the board afterwards I need to disconnect it first, reset doesn’t help.


So if you know of any changes I missed or did wrong, or are familiar with this type of gdb-errors, please help me out here.




Daniel Wagenknecht

Softwaredeveloper, R&D




Pirolweg 1-5

21337 Lüneburg | Germany


Fon: +49 4131 8901-7906

Fax: +49 4131 83200

E-Mail: daniel.wagenknecht@...






Zephyr-devel mailing list

Hi Daniel,

I was trying to get I2C working on stm32f3_disco a couple of months ago. You could find my local branch here (it needs a rebase to the master branch).
It just hangs after the line 41 of i2c_ll_stm32_v2.c like yours. It does not output any SYS_LOG on console. Below are the information I managed to collect.

Best regards,

openocd debugserver output:
Info : halted: PC: 0x08000b98
Info : halted: PC: 0x08000afc
Info : halted: PC: 0x00000000

gdb output
(gdb) next
41              LL_I2C_SetTransferRequest(i2c, transfer);
(gdb) next
0x00000000 in ?? ()
(gdb) bt --full
No symbol "full" in current context.
(gdb) bt full
#0  0x00000000 in ?? ()
No symbol table info available.
Backtrace stopped: previous frame identical to this frame (corrupt stack?)
(gdb) info frame
Stack level 0, frame at 0x0:
 pc = 0x0; saved pc = <unavailable>
 Outermost frame: previous frame identical to this frame (corrupt stack?)
 Arglist at unknown address.
 Locals at unknown address, Previous frame's sp is 0x0
(gdb) info registers
r0             0x0      0
r1             0x0      0
r2             0x0      0
r3             0x0      0
r4             0x0      0
r5             0x0      0
r6             0x0      0
r7             0x0      0
r8             0x0      0
r9             0x0      0
r10            0x0      0
r11            0x0      0
r12            0x0      0
sp             0x0      0x0
lr             0x0      0
pc             0x0      0x0
xPSR           0x0      0

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