Fix bug with unwanted read or write after I2C operation

[josesimoes]

Description

• Properly set ReadSize and WriteSize vars when setting up I2C operation (always have to set these, otherwise they'll be "reusing" the values from the last operation when there was no read or write buffer causing unwanted read or write after the real operation)
• This affects only the STM32 targets.

Motivation and Context

• Resolves I2C does not send correct data Home#319

How Has This Been Tested?

Screenshots

Types of changes

• Improvement (non-breaking change that improves a feature, code or algorithm)
• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have read the CONTRIBUTING document.
• I have added tests to cover my changes.
• All new and existing tests passed.

Signed-off-by: josesimoes [email protected]

[nfbot]

Hi @josesimoes,

I'm nanoFramework bot.
Thank you for your contribution!

A human will be reviewing it shortly. 😉

[josesimoes]

@MikroBusNet could please give this one a try with your collection of I2C devices? TIA!

[ghost]

First functionnal tests seem to show that it is working. I get expected results on (almost) all devices I have checked.
I have used a Quail with two eeproms, one ADXL345, one BME280 and one CY8C201A0. The latter failed (see below).

I have commited (by error as I wanted to create a branch) a change in the managed assembly to enable address "0", however. This address is valid and is used by some devices (e.g. CY8C201A0).

I will make more tests with the logic analyzer to confirm that the data sent/received is what is expected.

[ghost]

Complete test sequence with an Eeprom :

_eeprom.ReadByte(0);
0.000010000000000,I2C,Setup Write to ['172' (0xAC)] + ACK
0.000145550000000,I2C,'0' (0x00) + ACK
0.000235550000000,I2C,'0' (0x00) + ACK
0.005410450000000,I2C,Setup Read to ['173' (0xAD)] + ACK
0.005761900000000,I2C,'16' (0x10) + NAK

_eeprom.WriteByte(0, 17);
0.006406900000000,I2C,Setup Write to ['172' (0xAC)] + ACK
0.006609700000000,I2C,'0' (0x00) + ACK
0.006699700000000,I2C,'0' (0x00) + ACK
0.006789700000000,I2C,'17' (0x11) + ACK

_eeprom.ReadByte(0);
0.012066100000000,I2C,Setup Write to ['172' (0xAC)] + ACK
0.012229450000000,I2C,'0' (0x00) + ACK
0.012319450000000,I2C,'0' (0x00) + ACK
0.017516800000000,I2C,Setup Read to ['173' (0xAD)] + ACK
0.017840850000000,I2C,'17' (0x11) + NAK

_eeprom.ReadByte(231);
0.018449900000000,I2C,Setup Write to ['172' (0xAC)] + ACK
0.018545200000000,I2C,'0' (0x00) + ACK
0.018635200000000,I2C,'231' (0xE7) + ACK
0.023811500000000,I2C,Setup Read to ['173' (0xAD)] + ACK
0.024035050000000,I2C,'17' (0x11) + NAK

_eeprom.WriteByte(231, 18);
0.024659600000000,I2C,Setup Write to ['172' (0xAC)] + ACK
0.024755200000000,I2C,'0' (0x00) + ACK
0.024845200000000,I2C,'231' (0xE7) + ACK
0.024935200000000,I2C,'18' (0x12) + ACK

_eeprom.ReadByte(231);
0.030169200000000,I2C,Setup Write to ['172' (0xAC)] + ACK
0.030264550000000,I2C,'0' (0x00) + ACK
0.030354550000000,I2C,'231' (0xE7) + ACK
0.035516950000000,I2C,Setup Read to ['173' (0xAD)] + ACK
0.035612500000000,I2C,'18' (0x12) + NAK

_eeprom.WriteData(400, new Byte[] { 53, 54, 55 }, 0, 3);
0.036245650000000,I2C,Setup Write to ['172' (0xAC)] + ACK
0.036464500000000,I2C,'1' (0x01) + ACK
0.036554450000000,I2C,'144' (0x90) + ACK
0.036644450000000,I2C,5 (0x35) + ACK
0.036734450000000,I2C,6 (0x36) + ACK
0.036824450000000,I2C,7 (0x37) + ACK

_eeprom.ReadData(400, Data, 0, 3);
0.042056850000000,I2C,Setup Write to ['172' (0xAC)] + ACK
0.042351050000000,I2C,'1' (0x01) + ACK
0.042441050000000,I2C,'144' (0x90) + ACK
0.047610900000000,I2C,Setup Read to ['173' (0xAD)] + ACK
0.047713400000000,I2C,5 (0x35) + ACK
0.047803400000000,I2C,6 (0x36) + ACK
0.047893400000000,I2C,7 (0x37) + NAK

This is expected communication.

[josesimoes]

@MikroBusNet thank you vey much for your thorough testing and reporting! 💯 🥇