houston

Houston

Houston connects your lab equipment.

Usage

CLI

The command line interface is defined in cmd/dds/main.go and offers DDS control without any graphical or network interface.

See dds --help for details.

HTTP

The http interface is defined in cmd/http/main.go and offers DDS control over RESTful HTTP interface.

See http --help for details.

For a web application as frontend you can use houston-app.

HTTP Dev

The httpdev command is intended for development use only. It uses driver mockups to check if the HTTP interface uses the driver interface as expected without the need to have the hardware present.

Installation

We assume you have a working Go environment set up on your workstation and

go get -u github.com/gobuffalo/packr/...

executes successful. You can clone the source code via

export $REPO=github.com/bodokaiser/Houston

git clone https://$REPO $GOPATH/src/$REPO

and ensure dependencies by calling

dep ensure

inside the project directory. Install Go Dep if required.

From here you can easily cross compile binaries for ARM by running make and copy files to the target device:

scp -r bin debian@beaglebone.local:~/

Development

Code documentation is available online or can be hosted locally with godoc -http=:6060. To run tests do go test ./....

Appendix

How to enable SPI pins

Some Beaglebone pins are multi purpose and have to be configured accordingly.

In our case we need to set P9.17, P9.21, P9.18 and P9.22 to SPI mode, other pins can be left to be set to GPIO mode.

With recent releases (4.x linux kernel) you can easily configure the pins via

config-pin p9.17 spi_cs
config-pin p9.21 spi
config-pin p9.18 spi
config-pin p9.22 spi_sclk

or permanent if you ammend /boot/uEnv.txt to

dtb_overlay=/lib/firmware/BB-SPIDEV0-00A0.dtbo
disable_uboot_overlay_video=1
disable_uboot_overlay_audio=1
disable_uboot_overlay_wireless=1

in which the bootloader will enable SPI0 on startup.

How to connect to the Beaglebone

The preferable access to the Beaglebone is via SSH. The Beaglebone should broadcast itself as beaglebone.local yet there may be name conflicts if your network compromises multiple beaglebones.

For development it may be preferable to have internet access from the Beaglebone. In case your target network does not have internet access (like the notorius Labornetz) then we recommend to share the wifi connection over ethernet. For macOS you can enable this feature in the sharing settings, note that eduroam cannot be shared because too enterprise. On Windows we were not successful in getting this setup to work.

For low-level debugging for example if a kernel update went wrong, the bootloader was misconfigured or there is no network connection (no DHCP available or the like) you can still connect to the Beaglebone through a serial console, howbeit a serial (to usb) adapter will be necessary.

How to flash the internal MMC

This is necessary if your Beaglebone was delivered with an older image as we want to use Debian with a 4.x linux kernel.

We were not able to initiate the flashing procedure with Rev. A Beaglebones!

To update the internal MMC with the new image you need a micro SD card. You can find the available images here. We used the 2018-03-25 release with stretch-lxqt, however in retrospect stretch-console without the user interface bloat should be better fit.

Post download you need to extract the image and write it to the micro SD card

xzcat <bb-image>.img.xz | sudo dd of=/dev/disk2

and start the flash process by inserting the SD card into the unpowered Beaglebone, power on and hold the S2 until the LEDs start to flash.