Added display printing util function

This commit is contained in:
Gregor Riepl 2021-05-05 22:34:25 +02:00
parent 5e3bb96257
commit 81d154ebfa
3 changed files with 59 additions and 1 deletions

52
uncanny/display.go Normal file
View file

@ -0,0 +1,52 @@
package uncanny
import (
"errors"
"fmt"
"golang.org/x/text/encoding/charmap"
)
// encodeString encodes a Unicode string into a given charmap.
// Unsupported characters are replaced by the default replacement symbol.
// Mysteriously, this functionality is missing from x/text/encoding.
// TODO Implement the custom NEC display encoding.
func encodeString(s string) ([]byte) {
ret := make([]byte, len(s))
for i, c := range(s) {
ret[i], _ = charmap.ISO8859_1.EncodeRune(c)
}
return ret
}
func (c *Can) DisplayWrite(line int, a []byte) error {
var addr int
switch line {
case 0:
addr = 0x80
case 1:
addr = 0xc0
default:
return errors.New("Invalid line")
}
// print in 3 chunks, as one frame is limited to 8 bytes
// the display has only 16 characters per line, so we truncate there
if len(a) > 0 {
return c.bus.Publish(DisplayCommand{addr, a[:7]}.Encode())
}
if len(a) > 7 {
return c.bus.Publish(DisplayCommand{addr, a[7:14]}.Encode())
}
if len(a) > 14 {
return c.bus.Publish(DisplayCommand{addr, a[14:16]}.Encode())
}
return nil
}
func (c *Can) DisplayPrint(line int, a string) error {
return c.DisplayWrite(line, encodeString(a))
}
func (c *Can) DisplayPrintf(line int, a string, args ...interface{}) error {
s := fmt.Sprintf(a, args...)
return c.DisplayPrint(line, s)
}

View file

@ -2,4 +2,7 @@ module git.kabelsalat.ch/ccc-basel/matemat
go 1.11 go 1.11
require github.com/brutella/can v0.0.1 require (
github.com/brutella/can v0.0.1
golang.org/x/text v0.3.6
)

View file

@ -2,3 +2,6 @@ github.com/brutella/can v0.0.1 h1:Rz+2Zuje3NT79daon8wPN9+VphH3/kl1DP8Dhf/k1NI=
github.com/brutella/can v0.0.1/go.mod h1:NYDxbQito3w4+4DcjWs/fpQ3xyaFdpXw/KYqtZFU98k= github.com/brutella/can v0.0.1/go.mod h1:NYDxbQito3w4+4DcjWs/fpQ3xyaFdpXw/KYqtZFU98k=
golang.org/x/sys v0.0.0-20181213200352-4d1cda033e06 h1:0oC8rFnE+74kEmuHZ46F6KHsMr5Gx2gUQPuNz28iQZM= golang.org/x/sys v0.0.0-20181213200352-4d1cda033e06 h1:0oC8rFnE+74kEmuHZ46F6KHsMr5Gx2gUQPuNz28iQZM=
golang.org/x/sys v0.0.0-20181213200352-4d1cda033e06/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY= golang.org/x/sys v0.0.0-20181213200352-4d1cda033e06/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
golang.org/x/text v0.3.6 h1:aRYxNxv6iGQlyVaZmk6ZgYEDa+Jg18DxebPSrd6bg1M=
golang.org/x/text v0.3.6/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=
golang.org/x/tools v0.0.0-20180917221912-90fa682c2a6e/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=