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Update RPi driver to support full byte read/write

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This commit is contained in:
Terence Boldt 2021-01-15 22:40:29 -05:00
parent b0c59460ec
commit 9add4551d7
1 changed files with 79 additions and 50 deletions
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129
RaspberryPi/Driver.go
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@ -19,6 +19,10 @@ var out_write gpio.PinIO
var out_read gpio.PinIO
var out_commandWrite gpio.PinIO
var out_commandRead gpio.PinIO
var out_bit7 gpio.PinIO
var out_bit6 gpio.PinIO
var out_bit5 gpio.PinIO
var out_bit4 gpio.PinIO
var out_bit3 gpio.PinIO
var out_bit2 gpio.PinIO
var out_bit1 gpio.PinIO
@ -27,6 +31,10 @@ var in_write gpio.PinIO
var in_read gpio.PinIO
var in_commandWrite gpio.PinIO
var in_commandRead gpio.PinIO
var in_bit7 gpio.PinIO
var in_bit6 gpio.PinIO
var in_bit5 gpio.PinIO
var in_bit4 gpio.PinIO
var in_bit3 gpio.PinIO
var in_bit2 gpio.PinIO
var in_bit1 gpio.PinIO
@ -193,16 +201,24 @@ func writeBlock(buffer []byte) error {
func initGpio() {
out_write = gpioreg.ByName("GPIO5")
out_read = gpioreg.ByName("GPIO11")
out_commandWrite = gpioreg.ByName("GPIO9")
out_commandRead = gpioreg.ByName("GPIO10")
out_commandWrite = gpioreg.ByName("GPIO7")
out_commandRead = gpioreg.ByName("GPIO8")
out_bit7 = gpioreg.ByName("GPIO5")
out_bit6 = gpioreg.ByName("GPIO11")
out_bit5 = gpioreg.ByName("GPIO9")
out_bit4 = gpioreg.ByName("GPIO10")
out_bit3 = gpioreg.ByName("GPIO22")
out_bit2 = gpioreg.ByName("GPIO27")
out_bit1 = gpioreg.ByName("GPIO17")
out_bit0 = gpioreg.ByName("GPIO4")
in_write = gpioreg.ByName("GPIO12")
in_read = gpioreg.ByName("GPIO16")
in_commandWrite = gpioreg.ByName("GPIO20")
in_commandRead = gpioreg.ByName("GPIO21")
in_commandWrite = gpioreg.ByName("GPIO23")
in_commandRead = gpioreg.ByName("GPIO18")
in_bit7 = gpioreg.ByName("GPIO12")
in_bit6 = gpioreg.ByName("GPIO16")
in_bit5 = gpioreg.ByName("GPIO20")
in_bit4 = gpioreg.ByName("GPIO21")
in_bit3 = gpioreg.ByName("GPIO26")
in_bit2 = gpioreg.ByName("GPIO19")
in_bit1 = gpioreg.ByName("GPIO13")
@ -247,36 +263,8 @@ func writeString(outString string) error {
return nil
}
func readByte() (byte, error) {
data, err := readNibble()
data = data << byte(4)
if err != nil {
return 0, err
}
highNibble, err := readNibble()
if err != nil {
return 0, err
}
data += highNibble
//fmt.Printf("R%02X ", data)
return data, nil
}
func writeByte(data byte) error {
//fmt.Printf("W%02X ", data)
err := writeNibble(data >> 4)
if err != nil {
return err
}
err = writeNibble(data & 15)
if err != nil {
return err
}
return nil
}
func readNibble() (byte, error) {
// let the Apple II know we are ready to read
if debug {
fmt.Printf("let the Apple II know we are ready to read\n")
@ -290,34 +278,50 @@ func readNibble() (byte, error) {
for in_write.Read() == gpio.High {
if !in_write.WaitForEdge(edgeTimeout) {
if debug {
fmt.Printf("Timed out reading nibble -- write stuck high\n")
fmt.Printf("Timed out reading byte -- write stuck high\n")
}
return 0, errors.New("Timed out reading nibble -- write stuck high\n")
return 0, errors.New("Timed out reading byte -- write stuck high\n")
}
}
// get a nibble of data
if debug {
fmt.Printf("get a nibble of data\n")
fmt.Printf("get a byte of data\n")
}
var nibble byte
nibble = 0
var data byte
data = 0
bit7 := in_bit7.Read()
bit6 := in_bit6.Read()
bit5 := in_bit5.Read()
bit4 := in_bit4.Read()
bit3 := in_bit3.Read()
bit2 := in_bit2.Read()
bit1 := in_bit1.Read()
bit0 := in_bit0.Read()
if bit7 == gpio.High {
data += 128
}
if bit6 == gpio.High {
data += 64
}
if bit5 == gpio.High {
data += 32
}
if bit4 == gpio.High {
data += 16
}
if bit3 == gpio.High {
nibble += 8
data += 8
}
if bit2 == gpio.High {
nibble += 4
data += 4
}
if bit1 == gpio.High {
nibble += 2
data += 2
}
if bit0 == gpio.High {
nibble += 1
data += 1
}
// let the Apple II know we are done reading
@ -329,16 +333,16 @@ func readNibble() (byte, error) {
for in_write.Read() == gpio.Low {
if !in_write.WaitForEdge(edgeTimeout) {
if debug {
fmt.Printf("Timed out reading nibble -- write stuck low\n")
fmt.Printf("Timed out reading byte -- write stuck low\n")
}
return 0, errors.New("Timed out reading nibble -- write stuck low")
return 0, errors.New("Timed out reading byte -- write stuck low")
}
}
return nibble, nil
return data, nil
}
func writeNibble(data byte) error {
func writeByte(data byte) error {
// wait for the Apple II to be ready to read
if debug {
fmt.Printf("wait for the Apple II to be ready to read\n")
@ -346,16 +350,41 @@ func writeNibble(data byte) error {
for in_read.Read() == gpio.High {
if !in_read.WaitForEdge(edgeTimeout) {
if debug {
fmt.Printf("Timed out writing nibble -- read stuck high\n")
fmt.Printf("Timed out writing byte -- read stuck high\n")
}
return errors.New("Timed out writing nibble -- read stuck high")
return errors.New("Timed out writing byte -- read stuck high")
}
}
bit7 := gpio.Low
bit6 := gpio.Low
bit5 := gpio.Low
bit4 := gpio.Low
bit3 := gpio.Low
bit2 := gpio.Low
bit1 := gpio.Low
bit0 := gpio.Low
if ((data & 128) >> 7) == 1 {
bit7 = gpio.High
}
out_bit7.Out(bit7)
if ((data & 64) >> 6) == 1 {
bit6 = gpio.High
}
out_bit6.Out(bit6)
if ((data & 32) >> 5) == 1 {
bit5 = gpio.High
}
out_bit5.Out(bit5)
if ((data & 16) >> 4) == 1 {
bit4 = gpio.High
}
out_bit4.Out(bit4)
if ((data & 8) >> 3) == 1 {
bit3 = gpio.High
}
@ -387,9 +416,9 @@ func writeNibble(data byte) error {
for in_read.Read() == gpio.Low {
if !in_read.WaitForEdge(edgeTimeout) {
if debug {
fmt.Printf("Timed out writing nibble -- read stuck low\n")
fmt.Printf("Timed out writing byte -- read stuck low\n")
}
return errors.New("Timed out writing nibble -- read stuck low")
return errors.New("Timed out writing byte -- read stuck low")
}
}