fix tinkerboard i2c0 to i2c4, improve comments in pin map, improve RE…

…ADME

platforms/tinkerboard/README.md

@@ -6,7 +6,7 @@ For more info about the Tinker Board, go to [https://www.asus.com/uk/Single-Boar
 
 ## How to Install
 
-We recommend updating to the latest Debian TinkerOS when using the Tinker Board.
+We recommend updating to the [latest Debian TinkerOS](https://github.com/TinkerBoard/debian_kernel/releases) when using the Tinker Board.
 
 You would normally install Go and Gobot on your workstation. Once installed, cross compile your program on your workstation, transfer the final executable to your Tinker Board, and run the program on the Tinker Board as documented here.
 
@@ -18,10 +18,10 @@ go get -d -u gobot.io/x/gobot/...
 
 To enable use of the Tinker Board GPIO pins, you need to perform the following steps as a one-time configuration. Once your Tinker Board has been configured, you do not need to do so again.
 
-Note that these configuration steps must be performed on the Tinker Board itself. The easiest is to login to the Tinker Board via SSH:
+Note that these configuration steps must be performed on the Tinker Board itself. The easiest is to login to the Tinker Board via SSH (option "-4" is used to force IPv4, which is needed for some versions of TinkerOS):
 
 ```
-ssh [email protected]
+ssh -4 [email protected]
 ```
 
 #### Create a group "gpio"

platforms/tinkerboard/adaptor.go

@@ -22,7 +22,7 @@ type Adaptor struct {
  pinmap map[string]sysfsPin
  digitalPins map[int]*sysfs.DigitalPin
  pwmPins map[int]*sysfs.PWMPin
- i2cBuses [2]i2c.I2cDevice
+ i2cBuses [5]i2c.I2cDevice
  mutex *sync.Mutex
 }
 
@@ -195,12 +195,13 @@ func (c *Adaptor) PWMPin(pin string) (sysfsPin sysfs.PWMPinner, err error) {
 }
 
 // GetConnection returns a connection to a device on a specified bus.
-// Valid bus number is [0..1] which corresponds to /dev/i2c-0 through /dev/i2c-1.
+// Valid bus number is [0..4] which corresponds to /dev/i2c-0 through /dev/i2c-4.
+// We don't support "/dev/i2c-6 DesignWare HDMI".
 func (c *Adaptor) GetConnection(address int, bus int) (connection i2c.Connection, err error) {
  c.mutex.Lock()
  defer c.mutex.Unlock()
 
- if (bus < 0) || (bus > 1) {
+ if (bus < 0) || (bus > 4) {
  return nil, fmt.Errorf("Bus number %d out of range", bus)
  }
  if c.i2cBuses[bus] == nil {

platforms/tinkerboard/pin_map.go

@@ -2,115 +2,115 @@ package tinkerboard
 
 var fixedPins = map[string]sysfsPin{
  "7": {
- pin: 17, // GPIO0_C1
+ pin: 17, // GPIO0_C1_CLKOUT
  pwmPin: -1,
  },
  "10": {
- pin: 160, // GPIO5_B0
+ pin: 160, // GPIO5_B0_UART1RX
  pwmPin: -1,
  },
  "8": {
- pin: 161, // GPIO5_B1
+ pin: 161, // GPIO5_B1_UART1TX
  pwmPin: -1,
  },
  "16": {
- pin: 162, // GPIO5_B2
+ pin: 162, // GPIO5_B2_UART1CTSN
  pwmPin: -1,
  },
  "18": {
- pin: 163, // GPIO5_B3
+ pin: 163, // GPIO5_B3_UART1RTSN
  pwmPin: -1,
  },
  "11": {
- pin: 164, // GPIO5_B4
+ pin: 164, // GPIO5_B4_SPI0CLK_UART4CTSN
  pwmPin: -1,
  },
  "29": {
- pin: 165, // GPIO5_B5
+ pin: 165, // GPIO5_B5_SPI0CSN_UART4RTSN
  pwmPin: -1,
  },
  "13": {
- pin: 166, // GPIO5_B6
+ pin: 166, // GPIO5_B6_SPI0_TXD_UART4TX
  pwmPin: -1,
  },
  "15": {
- pin: 167, // GPIO5_B7
+ pin: 167, // GPIO5_B7_SPI0_RXD_UART4RX
  pwmPin: -1,
  },
  "31": {
- pin: 168, // GPIO5_C0
+ pin: 168, // GPIO5_C0_SPI0CSN1
  pwmPin: -1,
  },
  "22": {
  pin: 171, // GPIO5_C3
  pwmPin: -1,
  },
  "12": {
- pin: 184, // GPIO5_A0
+ pin: 184, // GPIO6_A0_PCM/I2S_CLK
  pwmPin: -1,
  },
  "35": {
- pin: 185, // GPIO5_A1
+ pin: 185, // GPIO6_A1_PCM/I2S_FS
  pwmPin: -1,
  },
  "38": {
- pin: 187, // GPIO5_A3
+ pin: 187, // GPIO6_A3_PCM/I2S_SDI
  pwmPin: -1,
  },
  "40": {
- pin: 188, // GPIO5_A4
+ pin: 188, // GPIO6_A4_PCM/I2S_SDO
  pwmPin: -1,
  },
  "36": {
- pin: 223, // GPIO5_A7
+ pin: 223, // GPIO7_A7_UART3RX
  pwmPin: -1,
  },
  "37": {
- pin: 224, // GPIO5_B0
+ pin: 224, // GPIO7_B0_UART3TX
  pwmPin: -1,
  },
  "27": {
- pin: 233, // GPIO5_C1
+ pin: 233, // GPIO7_C1_I2C4_SDA
  pwmPin: -1,
  },
  "28": {
- pin: 234, // GPIO5_C2
+ pin: 234, // GPIO7_C2_I2C_SCL
  pwmPin: -1,
  },
  "33": {
- pin: 238, // GPIO5_C6
+ pin: 238, // GPIO7_C6_UART2RX_PWM2
  pwmPin: 0,
  },
  "32": {
- pin: 239, // GPIO5_C7
+ pin: 239, // GPIO7_C7_UART2TX_PWM3
  pwmPin: 1,
  },
  "26": {
- pin: 251, // GPIO5_A3
+ pin: 251, // GPIO8_A3_SPI2CSN1
  pwmPin: -1,
  },
  "3": {
- pin: 252, // GPIO5_A4
+ pin: 252, // GPIO8_A4_I2C1_SDA
  pwmPin: -1,
  },
  "5": {
- pin: 253, // GPIO5_A3
+ pin: 253, // GPIO8_A5_I2C1_SCL
  pwmPin: -1,
  },
  "23": {
- pin: 254, // GPIO5_A6
+ pin: 254, // GPIO8_A6_SPI2CLK
  pwmPin: -1,
  },
  "24": {
- pin: 255, // GPIO5_A7
+ pin: 255, // GPIO8_A7_SPI2CSN0
  pwmPin: -1,
  },
  "21": {
- pin: 256, // GPIO5_B0
+ pin: 256, // GPIO8_B0_SPI2RXD
  pwmPin: -1,
  },
  "19": {
- pin: 257, // GPIO5_B1
+ pin: 257, // GPIO8_B1_SPI2TXD
  pwmPin: -1,
  },
 }