CH32V307 dev kit

[WhoTookMyNicks]

Hello,
I have connected two I2C modules (oled and bme280) to this board and the I2C scanner shows me this:

I2C Scanner
Scanning...
Unknown error at address 0x01
Unknown error at address 0x02
Unknown error at address 0x03
Unknown error at address 0x04
Unknown error at address 0x05
Unknown error at address 0x06
Unknown error at address 0x07
Unknown error at address 0x08
Unknown error at address 0x09
Unknown error at address 0x0A
Unknown error at address 0x0B
Unknown error at address 0x0C
Unknown error at address 0x0D
Unknown error at address 0x0E
Unknown error at address 0x0F
Unknown error at address 0x10
Unknown error at address 0x11
Unknown error at address 0x12
Unknown error at address 0x13
Unknown error at address 0x14
Unknown error at address 0x15
Unknown error at address 0x16
Unknown error at address 0x17
Unknown error at address 0x18
Unknown error at address 0x19
Unknown error at address 0x1A
Unknown error at address 0x1B
Unknown error at address 0x1C
Unknown error at address 0x1D
Unknown error at address 0x1E
Unknown error at address 0x1F
Unknown error at address 0x20
Unknown error at address 0x21
Unknown error at address 0x22
Unknown error at address 0x23
Unknown error at address 0x24
Unknown error at address 0x25
Unknown error at address 0x26
Unknown error at address 0x27
Unknown error at address 0x28
Unknown error at address 0x29
Unknown error at address 0x2A
Unknown error at address 0x2B
Unknown error at address 0x2C
Unknown error at address 0x2D
Unknown error at address 0x2E
Unknown error at address 0x2F
Unknown error at address 0x30
Unknown error at address 0x31
Unknown error at address 0x32
Unknown error at address 0x33
Unknown error at address 0x34
Unknown error at address 0x35
Unknown error at address 0x36
Unknown error at address 0x37
Unknown error at address 0x38
Unknown error at address 0x39
Unknown error at address 0x3A
Unknown error at address 0x3B
Unknown error at address 0x3C
Unknown error at address 0x3D
Unknown error at address 0x3E
Unknown error at address 0x3F
Unknown error at address 0x40
Unknown error at address 0x41
Unknown error at address 0x42
Unknown error at address 0x43
Unknown error at address 0x44
Unknown error at address 0x45
Unknown error at address 0x46
Unknown error at address 0x47
Unknown error at address 0x48
Unknown error at address 0x49
Unknown error at address 0x4A
Unknown error at address 0x4B
Unknown error at address 0x4C
Unknown error at address 0x4D
Unknown error at address 0x4E
Unknown error at address 0x4F
Unknown error at address 0x50
Unknown error at address 0x51
Unknown error at address 0x52
Unknown error at address 0x53
Unknown error at address 0x54
Unknown error at address 0x55
Unknown error at address 0x56
Unknown error at address 0x57
Unknown error at address 0x58
Unknown error at address 0x59
Unknown error at address 0x5A
Unknown error at address 0x5B
Unknown error at address 0x5C
Unknown error at address 0x5D
Unknown error at address 0x5E
Unknown error at address 0x5F
Unknown error at address 0x60
Unknown error at address 0x61
Unknown error at address 0x62
Unknown error at address 0x63
Unknown error at address 0x64
Unknown error at address 0x65
Unknown error at address 0x66
Unknown error at address 0x67
Unknown error at address 0x68
Unknown error at address 0x69
Unknown error at address 0x6A
Unknown error at address 0x6B
Unknown error at address 0x6C
Unknown error at address 0x6D
Unknown error at address 0x6E
Unknown error at address 0x6F
Unknown error at address 0x70
Unknown error at address 0x71
Unknown error at address 0x72
Unknown error at address 0x73
Unknown error at address 0x74
Unknown error at address 0x75
Unknown error at address 0x76
Unknown error at address 0x77
Unknown error at address 0x78
Unknown error at address 0x79
Unknown error at address 0x7A
Unknown error at address 0x7B
Unknown error at address 0x7C
Unknown error at address 0x7D
Unknown error at address 0x7E
No I2C devices found

The I2C scanner I started with Wire.begin(PB10, PB11); //scl, sda, as I connected the I2C devices here.

[maxint-rd]

Do you have release 1.0.4 updated with the latest code from the master branch?
For the CH32V003 I implemented merged PR #108 to support I2C scanning (and I2C slave).
Unfortunately I don't have the CH32V307, so I couldn't test this on that CPU.

With other CH32 chips I had also to ensure that the I2C lines had pull-ups, and that I2C was enabled.
In other experiments I encountered issues when using fast speed with iffy breadboard connections and long jumper wires. In some cases the power supplied gave issues and I had to add a capacitor or use 5V instead of 3v3.

[WhoTookMyNicks]

It is 1.0.4
Interestingly, in the package examples, there is no I2C scanner.
I tried your example from here but only added Wire.begin(PB10, PB11);
Now I get this:

Found 0 device(s).
Scanning again...
Done.

Wires are some 15cm, 5V. It's still the same.

[maxint-rd]

Interestingly, in the package examples, there is no I2C scanner.

To me that indicates that you only installed the released core, not the latest updates that can be found in the master branch. For the I2C update you need to copy the latest code of the master branch over the installed 1.0.4 code.
(BTW. In issue #124 someone initially had problems compiling for the v30x, but that was resolved in PR #126 and tested successfully. I'm not sure if @lyusupov also tested the scanning or what precise MCU he used).

In case you still have issues after updating the code:

• Do you have a logical analyzer that you can use to look at the I2C signals?
  To support scanning timeouts were reduced and on more occasions stops are generated. Using the analyzer you can have a deeper look.

• On CH32V307 PB10, PB11 are the I2C2 pins. Have you tried the standard I2C pins? (I2C1 SDA=PB7, SCL=PB6). I mean can you try Wire.begin() without parameters?
  The V003 only has one I2C port, so I have not tested scanning on second I2C channels.

• My tests were with default I2C speed (100K). You could try slower speeds.

[lyusupov]

@WhoTookMyNicks

I would not recommend to use Release 1.0.4 - try to apply "master" branch instead.
There are numerous Core fixes and updates since December 2023 (1.0.4 release date)

These are V307 Core features been qualified as doing quite good to me.
https://github.com/lyusupov/SoftRF/releases/tag/1.6

One may consider to pick some tips from my HAL source code:

1. https://github.com/lyusupov/SoftRF/blob/master/software/firmware/source/SoftRF/src/platform/CH32.cpp
2. https://github.com/lyusupov/SoftRF/blob/master/software/firmware/source/SoftRF/src/platform/CH32.h