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best adapter to access gpio with a gertduino connected

Former Member

I'm looking for ways  to get connections to the gpio port  and yet still be able to plug in the gertduino any ideas  would be   appreciated

  • As I understand it, the Gertduino uses I2C to talk to the Pi, but I2C is a shared bus that allows a number of devices to all connect to the same wires (the SDA/SCL connections) and each device identifies itself via an 8-bit id.

     

    First find out what id the the Gertduino is using using i2cdetect.  You can then use a different id with, for example, the MCP23017 chip.  Either make up your own board with the MCP23017 and solder some wires onto the back of the Raspberry Pi connector (which you can see in the corner of the Gertduino); you would only need the SDA (pin 3), SCL (pin 5) and a Ground connector. 

     

    Alternatively, there are a number of Raspberry Pi "GPIO Extender" boards you can buy with one or more 23017s in place.  Some of these boards have a Pi connector on one side and two rows of pin headers on the other side so you can stack the Gertduino on top of the GPIO expander board, which may be a physically more elegant solution. The 23017 extends a number of GPIO interfaces, with the advantage that you have some physical buffering to source/sink current, protecting the processor on the Pi from possible damage.

     

     

  • in reply to Former Member

    looks like a "pi wingman" maybe the best choice .

    fyi the gertduino connects to i2c, sdi , rx/tx  and 5v power on the gpio connector ,its just a pity some of the unused gpio ports aren't brought out to a connector .