Hi, I managed to properly connect to the temperature sensor, through the brick snap in port. I see the device on I2C bus 1 with address 0x48 and I can read its register without problems. I would like to connect another I2C device (IMU MPU9265), do I have to export GPIOs in order to connect it to one of the 4 I2C buses? Or I just need to wire the Vcc pin to the 5V or 3V3 pin on Neo, the GND pin to one of the GND pin on Neo, and SCL/SDA to pins SCL/SDA of the internal row on Neo? I did just that and I can't see the device appear on any of the four buses with i2cdetect. Connecting it to those pins I should see it on I2C2, i.e. with i2cdetect -y 1, right?
I have to try about the GPIO but check what voltage your sensor package supports - does it have a voltage regulator from goggle I see that it is a 3V3 sensor - so don't just connect it to 5V .. you have to use the i2c 2 bus on the j5 header if you want to access it from linux (possible this can be changed) http://www.udoo.org/docs-neo/Hardware_&_Accessories/I2C.html http://www.udoo.org/docs-neo/img/gionji/DOCS_i2c_pads.PNG on i2c 4 you can have also other sensors and access them from linux, but they have to have a different address as the already connected Neo 9-axis motion sensors. i2c 4 is on the external pins not internal.
Therefore only pins 34/35 and 36/37 are accessible from Linux? Is this written somewhere in documentation? And do I have to export GPIOs to make the device appear on the I2C bus? Or should it appear as soon as I plug in all the wires? Actually I have no other device attached to I2C 4 bus since it's a Neo Basic. Instead I have the brick temperature sensor which is connected to I2C 2 bus. Whatever bus I connect the new sensor to, anyway, it should not be a problem since it's address should be different according to the datasheet
You can use the Device Tree Editor to make the pinmuxing. Anyway, all the external row of pins is accessible from Linux.
Thank you Andrea. Anyway, I'm a complete noob with I2C, what I would like to know is: as soon as I wire an I2C device to power, ground, SDA and SCL pins I should immediately see it with the command i2cdetect on the correct bus number, is it correct? Inviato dal mio iPhone utilizzando Tapatalk
