USB 7-Segment Numeric Display

Manufactured by Delcom Engineering

Device Information

USB VENDOR_ID 0x0fc5 USB PRODUCT_ID 0x1227 Both the 6 character and 8 character displays have PRODUCT_ID, and according to Delcom Engineering no queryable information can be obtained from the device to tell them apart.

Device Modes

By default, the driver assumes the display is only 6 characters The mode for 6 characters is:

MSB 0x06; LSB 0x3f

For the 8 character display:

MSB 0x08; LSB 0xff

The device can accept “text” either in raw, hex, or ascii textmode. raw controls each segment manually, hex expects a value between 0-15 per character, ascii expects a value between ‘0’-‘9’ and ‘A’-‘F’. The default is ascii.

Device Operation

  1. Turn on the device: echo 1 > /sys/bus/usb/…/powered
  2. Set the device’s mode: echo $mode_msb > /sys/bus/usb/…/mode_msb echo $mode_lsb > /sys/bus/usb/…/mode_lsb
  3. Set the textmode: echo $textmode > /sys/bus/usb/…/textmode
  4. set the text (for example): echo “123ABC” > /sys/bus/usb/…/text (ascii) echo “A1B2” > /sys/bus/usb/…/text (ascii) echo -ne “x01x02x03” > /sys/bus/usb/…/text (hex)
  5. Set the decimal places. The device has either 6 or 8 decimal points. to set the nth decimal place calculate 10 ** n and echo it in to /sys/bus/usb/…/decimals To set multiple decimals points sum up each power. For example, to set the 0th and 3rd decimal place echo 1001 > /sys/bus/usb/…/decimals