Raspberry Pi, Arduino, Sensors and the data they produce

Sensor Project – Moving Forward – Part 2

After the prior success of the PiDome installation (with a couple glitches) I was all ramped up to see the first sensor get installed, and was hopeful it would be simple.

I first went to the Raspberry Pi [RPi]  to hook in the Arduino Pro Mini to the USB port and boom,  The RPi immediately rebooted, taking down the PiDome with it. Bummer!

Apparently the voltage drop is such that the RPi sees it as a problem!  With research, it is indicated that it is best to use a powered USB hub if you are going to hotswap. So if you don’t want this to happen, plug and unplug the USB devices when powered down, or use a powered USB hub, or use the new B+ and Pi2 which manage this current fluctuation better. I also see where a larger amperage of power supply might also alleviate this, so that is another experiment to follow.

This does also point out that I need to investigate the way I start up the PiDome as well. When I found that i was starting before the eth0: has an IP, thus confusing the webserver component, I took it out of the init sequence, and now I think I need to resolve that such that it can be automated, if the RPi restarts and I am not there, everything will be offline. A quick search shows the newer option in the OS to allow the boot to “wait” for the network stratup to complete before finishing, so tnow I can go back and put the PiDome back into the init.d script!

Back to the task at hand, the gateway was attached, but not yet recognized, as seen by the command: lsusb, I see the ftdi friend, but not the Arduino Pro Mini and 12cdetect -y 1 shows no devices, so I have a new problem to research.

The overall approach I am taking is this:


PiDome toBe diagram

The lsusb check shows this:


Now the 1c2detect shows nothing:

i2cdetect result

I will have to dig deeper to figure out why this is not being recognized, before any additional progress can be made.

My next step is to check the logs, and I find that indeed the system is finding the ftdi chip attached to my Arduino Pro Mini:

FTDI Uart Recognized

Now I will investigate how this uart is “spoken” to by PiDome.






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