The 16th Southern California Linux Expo (SCaLE 16X) is underway. I attended SCaLE 15X last year but frankly I was too new to Linux to get very much out of it. With a year’s worth of Linux fiddling under my belt, I hope to learn more this time. At the very least, I know more of the words used in the session descriptions!
I had planned out a tentative schedule and the first session was a walk through of the PocketBeagle device. This turned out to be the start of a three-day course titled Embedded Apprentice Linux Engineer (E-ALE) that was an additional, separate $75 charge on top of the conference fee, which I was unaware of. Most of that additional charge goes towards the included hardware:
- PocketBeagle with headers already soldered to its I/O pins.
- BaconBits assembled and ready to plug into a PocketBeagle
- MicroCenter-branded 16GB microSD card flashed with BeagleBone’s Debian distribution.
- Two micro-USB cables.
- One USB microSD card reader/writer
The parts and labor involved doesn’t quite add up to $75, but it’s close enough for me to decide to register on the spot. (Taking the final available slot.) This way I learn about embedded Linux and I’ll have a little pocket Linux computer to experiment and learn on.
I had thought the two micro-USB cables were redundant but they actually serve different purposes. One part of BaconBits is a serial over USB capability, and plugging in one cable to this port allows low-level serial communication to the PocketBeagle. The other micro USB port is on the PocketBeagle itself, where it presents its normal high-level network and mass storage device interfaces. Some of the exercises were made much easier by having both interfaces available.
PocketBeagle’s high-level web and mass-storage interfaces were straightforward, but I had little prior experience with low-level serial and stumbled a bit. The first (of many potential) solution that worked for me was to use
minicom and configure it (
minicom -s) to talk to the serial port
/dev/ttyUSB0 at 115200 baud, 8/N/1. This was enough to read the output, but in order for my keyboard input to be acknowledged, I also had to turn OFF hardware flow control. Otherwise it would act as read-only without the ability to interact with serial prompt. Can’t follow along with the exercises that way!