I2C write a buffer bug ?

[amirc2013]

Im trying to send a buffer over a I2C communication.
this is the code i used :

 Wire.beginTransmission(SCREEN_WRITE_addr);
  Wire.write(addr);
  unsigned char* ptr = data;
  for (int i = 0 ; i < len ; i++) {
    Wire.write(*ptr);
     if (DEBUG) {
      Serial.print("WE WROTE :");
      Serial.println(*ptr,HEX);
    }
    ptr++;
  }
  Wire.endTransmission(true);

some how only the last byte has been sent ... why ?

[amirc2013]

it seems like it is depended on the size of what im sending ... so ... can anyone explain why ?

[fpistm]

Hi @amirc2013
could you be more precise about your issue as described in the GitHub issue template:
Describe the bug
A clear and concise description of what the bug is.

To Reproduce
Complete source code which can be used to reproduce the issue. Please try to be as generic as possible (no extra code, extra hardware,...)

Desktop (please complete the following information):

• OS: [e.g. Windows]
• Arduino IDE version: [e.g. 1.8.8]
• STM32 core version: [e.g. 1.4.0]
• Tools menu settings if not the default: [e.g. Newlib Standard, No Serial]
• Upload method: [e.g. STLink]

Board (please complete the following information):

• Name: [e.g. Nucleo F429ZI]
• Hardware Revision: [e.g. Rev B]
• Extra hardware used if any: [e.g. X-Nucleo IKS01A1]

Additional context
Add any other context about the problem here.

Full sketch. Which I2C device you used. how it is wired. Do you use PULLUP resistors on the line...

[fpistm]

@amirc2013
without any feedback I will close this issue.

[amirc2013]

Bug :
Can't write a big buffer to the i2c line. Seems like there is a limitation which I can't find where or why.

[fpistm]

@amirc2013
OK but you do not provide enough information.
Which board you used, which I2C hardware, how it is wired.
As said I could not help without more info.
I do not ask to close the issue, only to have more info to be able to help...

[amirc2013]

I will send everything later when I come back home ok ? Thanks

…

On Tue, Sep 24, 2019, 11:13 Frederic Pillon ***@***.***> wrote: @amirc2013 <https://github.com/amirc2013> OK but you do not provide enough information. Which board you used, which I2C hardware, how it is wired. As said I could not help without more info. I do not ask to close the issue, only to have more info to be able to help... — You are receiving this because you were mentioned. Reply to this email directly, view it on GitHub <#661?email_source=notifications&email_token=ACX2F4UVHRE2SNUOD5GHMYTQLHD4DA5CNFSM4IYOIVM2YY3PNVWWK3TUL52HS4DFVREXG43VMVBW63LNMVXHJKTDN5WW2ZLOORPWSZGOD7NQAQA#issuecomment-534446144>, or mute the thread <https://github.com/notifications/unsubscribe-auth/ACX2F4S5MNJ7YDGMX3CQDJDQLHD4DANCNFSM4IYOIVMQ> .

[fpistm]

No worries ;)

I2C buffer is 32 bytes. Maybe that is the problem?

[fpistm]

Right by default I2C_BUFFER is 32 bytes but it is a dynamic allocated buffer which can growth if needed.
I ask about more info because if @amirc2013 used the GitHub repository then he could met an issue I've seen after repeated start feature introduction. For the 1.7.0, I've revert it.
So, while I do not get all info I could not help.

[amirc2013]

Writing and uploading an answer right now. sorry for the delay ‫בתאריך יום ג׳, 24 בספט׳ 2019 ב-11:42 מאת ‪Frederic Pillon‬‏ <‪ notifications@github.com‬‏>:‬

…

No worries ;) — You are receiving this because you were mentioned. Reply to this email directly, view it on GitHub <#661?email_source=notifications&email_token=ACX2F4SZX6FEXDHJJEJCPTLQLHHHXA5CNFSM4IYOIVM2YY3PNVWWK3TUL52HS4DFVREXG43VMVBW63LNMVXHJKTDN5WW2ZLOORPWSZGOD7NSYDQ#issuecomment-534457358>, or mute the thread <https://github.com/notifications/unsubscribe-auth/ACX2F4U2KX3GSP3EQKTXGG3QLHHHXANCNFSM4IYOIVMQ> .

[amirc2013]

This is the simple formation of the code Im using for writing to the I2C.

My Real Program is really big and it is not understandalbe
so for this issue I will just use this instead.

static inline void i2c_write(
unsigned short addr,
unsigned char *data,
unsigned short len)
{
Wire.beginTransmission(SLAVE_addr);
Wire.write(addr);
Wire.write((const uint8_t *)data,(size_t)len);
Wire.endTransmission(true);
}

The bug :
When I'm writing a big data to this function - I just cant see then on my logic analyzer.
Only when I cut them down to 0x1000/10 bytes I will be able to see them.
This is super weird. Cause I need to write in 0x1000 chunk size...

My board : Nucleo L4R5ZI
OS: Windows
Arduino IDE version: 1.8.10
STM32 core version: How can I check that ?
Tools menu settings if not the default. Newlib Nano (default)
Upload method: Mass storage

Hardware Revision:How can I check that ?

I don't use any extra pull-up resistors.. Only connect a micro-controller to my STM with level shifter in the middle.

[fpistm]

STM32 core version: How can I check that ?

How did you install it? Boards manager? Using git repo? Anyway you can check here:

Arduino_Core_STM32/cores/arduino/stm32/stm32_def.h

Lines 5 to 21 in fb57942

	/**
	* @brief STM32 core version number
	*/
	#define STM32_CORE_VERSION_MAJOR (0x01U) /*!< [31:24] major version */
	#define STM32_CORE_VERSION_MINOR (0x07U) /*!< [23:16] minor version */
	#define STM32_CORE_VERSION_PATCH (0x00U) /*!< [15:8] patch version */
	/*
	* Extra label for development:
	* 0: official release
	* [1-9]: release candidate
	* F[0-9]: development
	*/
	#define STM32_CORE_VERSION_EXTRA (0x00U) /*!< [7:0] extra version */
	#define STM32_CORE_VERSION ((STM32_CORE_VERSION_MAJOR << 24U)\
	|(STM32_CORE_VERSION_MINOR << 16U)\
	|(STM32_CORE_VERSION_PATCH << 8U )\
	|(STM32_CORE_VERSION_EXTRA))

Hardware Revision:How can I check that ?
on the sticker you should have something like MB1312 X where X is is the revision, anyway this is not very important in our case.

I don't use any extra pull-up resistors.. Only connect a micro-controller to my STM with level shifter in the middle.

Could you be more precise about this? which microconttoller and level shifter? how are they wired.
I2C lines require PULL up so ensure to have them on your wiring.