Servo 1.0 protocol - Revision history

Rew: /* Write ports */

2021-11-16T13:51:17Z

Write ports

2021-11-16T13:50:45Z

Write ports

2021-11-16T13:49:47Z

Write ports

2020-11-22T13:54:04Z

Write ports

2020-11-22T13:53:18Z

Write ports

2020-11-22T13:53:07Z

Write ports

2020-11-22T13:52:15Z

Write ports

2020-11-22T13:43:34Z

Read identification

2015-11-30T14:22:30Z

write ports

2015-11-30T14:22:12Z

write ports

@@ Line 20: / Line 20: @@
 | 0x12 || 8 bit register. Each bit controls the enable of an output. If disabled (0) the output drops to zero. Some servos stop wiggling, become back-drivable and consume less power in this state.
 |-
-| 0x20-0x26 || 8 bit register. Set servo 0-6 position. The pulse width changes from about 1ms for 0 to about 2ms for 0xff. To "overdrive" your servos you need to use 0x28-0x2e or adjust the offset and scaling using 0x58/0x59.
+| 0x20-0x26 || 8 bit register. Set servo 0-6 position. The pulse width changes from about 1.00ms for 0 to about 2.00ms for 0xff. To "overdrive" your servos you need to use 0x28-0x2e or adjust the offset and scaling using 0x58/0x59.
 |-
 | 0x28-0x2e || (*) 16 bit register. Set servo 0-6 timing in microseconds. Don't set values larger than 2500. (if you do, funny things will happen if the total of all servos exceeds 20 miliseconds. Don't set the value too low. I expect you'll get pulses that are 20 miliseconds too long if you do.

@@ Line 20: / Line 20: @@
 | 0x12 || 8 bit register. Each bit controls the enable of an output. If disabled (0) the output drops to zero. Some servos stop wiggling, become back-drivable and consume less power in this state.
 |-
-| 0x20-0x26 || 8 bit register. Set servo 0-6 position. The pulse width changes from about 1ms for 0 to about 2ms for 0xff. To "overdrive" your servos you need to use 0x28-0x2e.
+| 0x20-0x26 || 8 bit register. Set servo 0-6 position. The pulse width changes from about 1ms for 0 to about 2ms for 0xff. To "overdrive" your servos you need to use 0x28-0x2e or adjust the offset and scaling using 0x58/0x59.
 |-
 | 0x28-0x2e || (*) 16 bit register. Set servo 0-6 timing in microseconds. Don't set values larger than 2500. (if you do, funny things will happen if the total of all servos exceeds 20 miliseconds. Don't set the value too low. I expect you'll get pulses that are 20 miliseconds too long if you do.

@@ Line 15: / Line 15: @@
 {| border=1
 ! port !! function
+|-
+| 0x10-0x11 || 8 bit register. Reserved for debug. Do not write to these registers.
+|-
+| 0x12 || 8 bit register. Each bit controls the enable of an output. If disabled (0) the output drops to zero. Some servos stop wiggling, become back-drivable and consume less power in this state.
 |-
 | 0x20-0x26 || 8 bit register. Set servo 0-6 position. The pulse width changes from about 1ms for 0 to about 2ms for 0xff. To "overdrive" your servos you need to use 0x28-0x2e.

@@ Line 18: / Line 18: @@
 | 0x20-0x26 || 8 bit register. Set servo 0-6 position. The pulse width changes from about 1ms for 0 to about 2ms for 0xff. To "overdrive" your servos you need to use 0x28-0x2e.
 |-
-| 0x28-0x2e || (*) 16 bit register. Set servo 0-6 position in microseconds. Don't set values larger than 2500. (if you do, funny things will happen if the total of all servos exceeds 20 miliseconds. Don't set the value too low. I expect you'll get pulses that are 20 miliseconds too long if you do.
+| 0x28-0x2e || (*) 16 bit register. Set servo 0-6 timing in microseconds. Don't set values larger than 2500. (if you do, funny things will happen if the total of all servos exceeds 20 miliseconds. Don't set the value too low. I expect you'll get pulses that are 20 miliseconds too long if you do.
 |-
 | 0x30-0x36 || (*) 8 bit register. Set the default value for this servo. This value is used when the board is powered up. This value is stored in non volatile memory.

@@ Line 40: / Line 40: @@
 |}
 (*) From version 1.1 and up.
 (#) From version 2.1 and up. (0x50 from 2.0)

@@ Line 24: / Line 24: @@
 | 0x38-0x3e || (*) 8 bit register. Set the timeout value in tenths of a second. (5 = 0.5 seconds, 35=3.5 seconds). If no update of this servo is received within the timeout time, the servo will revert to the default value.
 |-
-| 0x50 || set servo values as an array. Write 1-7 servo position bytes (always starting at servo 0) in one transaction.
+| 0x50 || (#) set servo values as an array. Write 1-7 servo position bytes (always starting at servo 0) in one transaction.
 |-
-| 0x51 || set servo values as an array. Write 1-7 servo timing values (16 bits/servo) in one transaction.
+| 0x51 || (#) set servo values as an array. Write 1-7 servo timing values (16 bits/servo) in one transaction.
 |-
-| 0x58 || 8bit servo positions are converted to 16 bit timing values using tv = base + pos*mul; default base = 988 giving the normal 1000-2000 microsecond timing value range. This register is 16 bits and modifies the base.
+| 0x58 || (#) 8bit servo positions are converted to 16 bit timing values using tv = base + pos*mul; default base = 988 giving the normal 1000-2000 microsecond timing value range. This register is 16 bits and modifies the base.
 |-
-| 0x59 || this changes the multiplication factor. See 0x58.
+| 0x59 || (#) this changes the multiplication factor. See 0x58.
 |-
@@ Line 40: / Line 40: @@
 |}
 (*) From version 1.1 and up.
+(#) From version 2.1 and up. (0x50 from 2.0)
 = Read ports =

@@ Line 55: / Line 55: @@
 ! data sent !! data recieved || explanation
 |-
-| 0x87 || xx || select destination with address 0x82 for READ.
+| 0x87 || xx || select destination with address 0x86 for READ.
 |-
 | 0x01 || xx || identify

@@ Line 8: / Line 8: @@
 The default address of the servo board is 0x86.
-= write ports =
+= Write ports =
 The ports on the servo board just set a single byte-value. So writing more than one byte to such a port is redundant.

@@ Line 24: / Line 24: @@
 | 0x38-0x3e || (*) 8 bit register. Set the timeout value in tenths of a second. (5 = 0.5 seconds, 35=3.5 seconds). If no update of this servo is received within the timeout time, the servo will revert to the default value.
 |-
-| 0xf0 || change address.
+| 0xf0 || Change address. Requires a write to 0xf1 and 0xf2 first.
+|-
+| 0xf1 || Write 0x55 here to start unlocking the change address register.
+|-
+| 0xf2 || Write 0xaa here to unlock the change address register.
 |}
 (*) From version 1.1 and up.