Using the Sunny Beam under Linux: Not OK - yet?

update 13/6/2009: check out my new sunnybeamtool command line application.

As mentioned in my previous post, I have a "Sunny Beam" appliance that monitors the electricity production of my solar panels. The Beam maintains a wireless connection with the inverter to capture the power data. The clean LCD display offers a nice graph and the module recharges its batteries with solar cells. In addition, the Sunny Beam has a USB connection to send the data to a PC. Unfortunately, the Sunny Beam uses no standard 'USB mass storage' interface, but requires a Windows-only USB-driver. SMA.de responded to my mail stating that "The Sunny Beam can only work on windows operating systems. Windows 2000, XP (32 and 64) and Vista (32)". It is sad to see that succesful companies ignore the fact that other operating systems like MacOS and Linux are becoming increasingly popular. I'm not a Mac-fanboy, but MacOS has around 9% market share according to this site.

Once the USB driver is setup under Windows, you must use the complex Sunny Data Control application to gather the data. It is not a simple program to use, especially for small scaled solar systems. You really need to dive into the manual to get started. SMA informed me that a new, simpler application will be released in the beginning of 2009. According to the sma-america.com site, this new program will probably be called 'Sunny Beam WebConnect'.

I tried to install the Sunny Data Control under the latest version of Wine HQ. By default Ubuntu provides an outdated version of Wine, but upgrading is well documented on the Wine site. The application installs seamingly and starts fine; I even managed to register the USB driver with the following command:

wine rundll32 setupapi.dll,InstallHinfSection DefaultInstall 128 Desktop/sbeamdriver/SBeamUSB.inf

Unfortunatly, I found out that USB kernel drivers are not supported in Wine. Dead end street...

Next, I found out that SMA provides a C library, YASDI -- 'Yet Another SMA Device Interface' -- for generic low-level access to their inverter interfaces. The Yasdi-API has everything to convince me: it's LGPL, linux is supported out-of-the box, Java JNI wrappers exist and it has a nice layered architecture where the technical drivers are decoupled from higher layers like the protocol-handling. Unfortunatly, Yasdi has no USB driver. I contacted the author of Yasdi, to check if the Sunny Beam fits in the standard Yasdi-API framework concept, so it would be easy to add the USB driver to it. Bad luck, Heiko informed me that the protocol used in SunnyBeam is a little bit different from other -- I suppose older -- devices. In order to add the SunnyBeam module to Yasdi, the protocol-layers will have to be adapted. I suppose the YASDI support and development is frozen at SMA.

The suggestion I got from Heiko is to use VMware or VirtualBox to run a Windows-system. Since my system is dual-boot (Windows is the last -- painful -- option) this doesn't add much value to the setup. Other suggestions are welkom.

The device presents itself to Ubuntu as follows:

$ lsusb -v
Bus 001 Device 002: ID 1587:002d SMA Technologie AG
Device Descriptor:
bLength                18
bDescriptorType         1
bcdUSB               1.10
bDeviceClass            0 (Defined at Interface level)
bDeviceSubClass         0
bDeviceProtocol         0
bMaxPacketSize0         8
idVendor           0x1587 SMA Technologie AG
idProduct          0x002d
bcdDevice            2.00
iManufacturer           1 SMA Technologie AG
iProduct                2 Sunny Beam
iSerial                 3 00024383
bNumConfigurations      1
Configuration Descriptor:
bLength                 9
bDescriptorType         2
wTotalLength           32
bNumInterfaces          1
bConfigurationValue     1
iConfiguration          0
bmAttributes         0xa0
(Bus Powered)
Remote Wakeup
MaxPower              200mA
Interface Descriptor:
bLength                 9
bDescriptorType         4
bInterfaceNumber        0
bAlternateSetting       0
bNumEndpoints           2
bInterfaceClass       255 Vendor Specific Class
bInterfaceSubClass    255 Vendor Specific Subclass
bInterfaceProtocol    255 Vendor Specific Protocol
iInterface              2 Sunny Beam
Endpoint Descriptor:
bLength                 7
bDescriptorType         5
bEndpointAddress     0x81  EP 1 IN
bmAttributes            2
  Transfer Type            Bulk
  Synch Type               None
  Usage Type               Data
wMaxPacketSize     0x0040  1x 64 bytes
bInterval               0
Endpoint Descriptor:
bLength                 7
bDescriptorType         5
bEndpointAddress     0x02  EP 2 OUT
bmAttributes            2
  Transfer Type            Bulk
  Synch Type               None
  Usage Type               Data
wMaxPacketSize     0x0040  1x 64 bytes
bInterval               0
Device Status:     0x0000
(Bus Powered)
$ dmesg | tail
[ 3100.544038] usb 1-1: new full speed USB device using uhci_hcd and address 2
[ 3100.781392] usb 1-1: configuration #1 chosen from 1 choice