Webserial, Byte Communication for I2C Writing / Reading

[lightwoheat]

I have an M5StickCPlus2 = v 1.4 Bus Pirate and I have a Xaio with v 1.6 Bit Pirate

I am able to connect via WebSerial and successfully do I2C Transactions but done as bytes representing ascii. I am wanting instead to send communication as bytes to perform i2c reads and writes.

1. Can you point me to how I can change from Terminal mode to some other mode that allows for me to do i2c reads/writes.
2. Once in this mode, can you point me to the commands that I would send for i2c reads/writes

M5StickCPlus I was able to load the FW but only been successful via the M5Stack Burner Utility. Version on there is v 1.4, if there is a newer version for this device, can you point me to it?

• Thanks!

[geo-tp]

You are currently using the WebSerial terminal, so what you send is parsed as text/ASCII commands.

For normal I2C use, switch to I2C mode and use the CLI commands:

mode i2c
config
scan
read 0x3C 0x00
write 0x3C 0x01 0xFF
dump 0x50 128

If you want something closer to byte-level control, use the instruction syntax, scripting lab or web bit bang controller, see docs

https://github.com/geo-tp/ESP32-Bit-Pirate/wiki/05-I2C
https://github.com/geo-tp/ESP32-Bit-Pirate/wiki/99-Adapters
https://geo-tp.github.io/ESP32-Bit-Pirate/recipes/

Web tools related:
https://geo-tp.github.io/ESP32-Bit-Pirate/web-tools/python-lab/
https://geo-tp.github.io/ESP32-Bit-Pirate/web-tools/bpio2/ (requires up to date build, not available in 1.6)

For the M5StickCPlus2, it is no longer supported, you can still use the latest available version (on M5Burner)

[lightwoheat]

on the Xaio am I able to run an "up to date build" I have v 1.6 which I got from the web flasher tool (https://geo-tp.github.io/ESP32-Bit-Pirate/webflasher/) Do I need to go somewhere else to get the "up to date build"?

Thank you

[fdufnews]

Do I need to go somewhere else to get the "up to date build"?

If you need a build more recent than the one in the official release, you need to compile it from source.
You must :

• Install Visual Studio Code + pioarduino extension.
• Download the source from Github
• Select the environment corresponding to your target
• Compile and download the new firmware.

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I am not sure you need a newer version just to read/write to an I2C device.
You can use instructions as explained in the wiki
For example, if you enter the following line in the terminal while in I2C mode:

[0x0d 0x0a 0x01][D:10][0xD 0x03][r:6]

You send 0x0A and 0x01 to an I2C device at adress 0x0D
You wait 10ms
You send 0x03 to the same device at adress 0x0D
You read 6 bytes from the device

[VectorPeak]

There are two separate paths here: the terminal/CLI is still ASCII input, even when you type hex values; the firmware parses those tokens and performs the I2C transaction. For a more byte-oriented I2C transaction from the CLI, use the bracket sequence syntax:

mode i2c
config
[0x3C 0x00 r:4] # write register 0x00, then read 4 bytes
[0x3C 0x01 0xFF] # write bytes to address 0x3C

For an actual adapter-style workflow, switch the device into the BPIO2 GPIO/SPI/I2C USB adapter, then reconnect with the BPIO2 web tool instead of the terminal:

mode usb
adapter
# choose: BPIO2 GPIO/SPI/I2C

In BPIO2 I2C, use 7-bit address + “Write bytes” + “Read length”; for register reads, put the register address in “Write bytes” and set the read length. I2C uses IO1=SCL and IO2=SDA in that adapter mode. (geo-tp.github.io)

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