0001 =============================
0002 USB 7-Segment Numeric Display
0003 =============================
0004
0005 Manufactured by Delcom Engineering
0006
0007 Device Information
0008 ------------------
0009 USB VENDOR_ID 0x0fc5
0010 USB PRODUCT_ID 0x1227
0011 Both the 6 character and 8 character displays have PRODUCT_ID,
0012 and according to Delcom Engineering no queryable information
0013 can be obtained from the device to tell them apart.
0014
0015 Device Modes
0016 ------------
0017 By default, the driver assumes the display is only 6 characters
0018 The mode for 6 characters is:
0019
0020 MSB 0x06; LSB 0x3f
0021
0022 For the 8 character display:
0023
0024 MSB 0x08; LSB 0xff
0025
0026 The device can accept "text" either in raw, hex, or ascii textmode.
0027 raw controls each segment manually,
0028 hex expects a value between 0-15 per character,
0029 ascii expects a value between '0'-'9' and 'A'-'F'.
0030 The default is ascii.
0031
0032 Device Operation
0033 ----------------
0034 1. Turn on the device:
0035 echo 1 > /sys/bus/usb/.../powered
0036 2. Set the device's mode:
0037 echo $mode_msb > /sys/bus/usb/.../mode_msb
0038 echo $mode_lsb > /sys/bus/usb/.../mode_lsb
0039 3. Set the textmode:
0040 echo $textmode > /sys/bus/usb/.../textmode
0041 4. set the text (for example):
0042 echo "123ABC" > /sys/bus/usb/.../text (ascii)
0043 echo "A1B2" > /sys/bus/usb/.../text (ascii)
0044 echo -ne "\x01\x02\x03" > /sys/bus/usb/.../text (hex)
0045 5. Set the decimal places.
0046 The device has either 6 or 8 decimal points.
0047 to set the nth decimal place calculate 10 ** n
0048 and echo it in to /sys/bus/usb/.../decimals
0049 To set multiple decimals points sum up each power.
0050 For example, to set the 0th and 3rd decimal place
0051 echo 1001 > /sys/bus/usb/.../decimals
