I2c Availability?

[jdh2550]

Hi,

Is there an I2C bus implemented on the board anywhere? (i.e. for attaching some peripherals?). I know that one of the UARTs on the external connector can be re-purposed to drive I2C (according to an MWeston post). But if I do that I risk conflicts with other folks projects - if there were an I2C bus already available then that would be GREAT!

If not, oh well, never mind.

 

[Squidge]

Yes there is, and last I heard, there's a user accessible connector providing it (Note however that if your device malfunctions, it can stop the Pandora from working as it uses the i2c bus internally).

Without taking the case apart, you can change one of the UARTs on the ext connector to a software i2c. This is the preferred method, as it's seperate from the internal one.

 

[MWeston]

The nub controllers on the old PCB used SPI and so I2C3 was available on the expansion connector, but the new controllers use I2C so I had to take over those pins.

You could solder wires to the pullup resistors if you wanted to make your own adventures but that is an internal mod. I didn't want anything that could affect the system brought out externally as stability of the Pandora itself was my first priority. The AV connector even has its own power supply that can be turned on and off and set to many different voltage levels for versatility. As Squidge says, you could also do a software I2C on the reconfigurable UART/GPIO pins on the AV connector. It also looks like four of those pins can be configured as PWM signals that could maybe find a use driving H-Bridge circuits and adding wheels to Pandora for robotic projects. Hmmn, fun

 

[dentrado]

It also looks like four of those pins can be configured as PWM signals that could maybe find a use driving H-Bridge circuits and adding wheels to Pandora for robotic projects. Hmmn, fun

awesome!

(got me thinking of this)

 

[atomicthumbs]

The nub controllers on the old PCB used SPI and so I2C3 was available on the expansion connector, but the new controllers use I2C so I had to take over those pins.

You could solder wires to the pullup resistors if you wanted to make your own adventures but that is an internal mod. I didn't want anything that could affect the system brought out externally as stability of the Pandora itself was my first priority. The AV connector even has its own power supply that can be turned on and off and set to many different voltage levels for versatility. As Squidge says, you could also do a software I2C on the reconfigurable UART/GPIO pins on the AV connector. It also looks like four of those pins can be configured as PWM signals that could maybe find a use driving H-Bridge circuits and adding wheels to Pandora for robotic projects. Hmmn, fun

What kind of voltage levels? Could it do 12 volts?

Hmmmm......

 

[Squidge]

What kind of voltage levels? Could it do 12 volts?

Highly unlikely. More like between 3.3V and 5V I would say.

 

[notaz]

1.5 - 3.0V

 

[atomicthumbs]

1.5 - 3.0V

thanks

What kind of current capacity does it have?

 

[MWeston]

thanks

What kind of current capacity does it have?

up to 200mA