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I have recently purchase a RoboClaw 25x2 controller but I am having problem using packet command with speed parameters. Note the enoder OK bit is clear (FAIL). I believe the encoders are connected properly and I have observed square wave inputs on both M1/M2 A and B inputs.

Below is the output of test program showing the problem:

80 15 52 6F 62 6F 43 6C 61 77 20 32 35 78 32 20 76 32 2E 30 2E 31 0A 00
Firmware: RoboClaw 25x2 v2.0.1

Debug                       Command par/value		Comment
80 18 00 78 10              Main Battery 120
80 19 00 3E D7              Logic Battery 62            Checksum bit 8 set
80 12 00 00 00 00 00 12     Read Speed M1 0,00		Encoder OK bit = 0 (Fail)
80 13 00 00 00 00 00 13     Read Speed M2 0,00		Encoder OK bit = 0 (Fail)
80 23 00 00 04 4C F3        DriveSpeed_M1(1100)		Motor 1 does not spin
80 24 00 00 04 4C F4        DriveSpeed_M2(1100)         Motor 2 does not spin
80 12 00 00 00 00 00 12     Read Speed M1 0,00		Encoder OK bit = 0 (Fail)
80 13 00 00 00 00 00 13     Read Speed M2 0,00
80 08 20 A8                 DriveForward_M1(32)         Motors both spin forward
80 12 00 00 09 D5 00 70     Read Speed M1 2517,00	Encoder OK bit = 0 (Fail)
80 13 00 00 09 18 00 34     Read Speed M2 2328,00	Encoder OK bit = 0 (Fail)
80 12 00 00 09 D4 00 6F     Read Speed M1 2516,00
80 13 00 00 09 19 00 35     Read Speed M2 2329,00
80 12 00 00 09 D3 00 6E     Read Speed M1 2515,00
80 13 00 00 09 19 00 35     Read Speed M2 2329,00
80 12 00 00 09 D3 00 6E     Read Speed M1 2515,00
80 13 00 00 09 1A 00 36     Read Speed M2 2330,00
80 23 00 00 04 B0 57        DriveSpeed_M1(1200)         Motor 1 stops
80 24 00 00 04 B0 58        DriveSpeed_M2(1200)         Motor 2 stops
80 12 00 00 00 00 00 12     Read Speed M1 0,00		Encoder OK bit = 0 (Fail)
80 13 00 00 00 00 00 13     Read Speed M2 0,00
80 08 20 A8                 DriveForward_M1(32)         Both motors spin
80 12 00 00 09 FB 00 16     Read Speed M1 2555,00
80 13 00 00 09 3F 00 5B     Read Speed M2 2367,00
80 12 00 00 09 FC 00 17     Read Speed M1 2556,00
80 13 00 00 09 40 00 5C     Read Speed M2 2368,00
80 12 00 00 09 FB 00 16     Read Speed M1 2555,00
80 13 00 00 09 40 00 5C     Read Speed M2 2368,00
80 12 00 00 09 FC 00 17     Read Speed M1 2556,00
80 13 00 00 09 40 00 5C     Read Speed M2 2368,00
80 23 00 00 05 14 BC        DriveSpeed_M1(1300)         Motor 1 stops
80 24 00 00 05 14 BD        DriveSpeed_M2(1300)         Motor 2 stops
80 12 00 00 00 00 00 12     Read Speed M1 0,00
80 13 00 00 00 00 00 13     Read Speed M2 0,00
...
...

I got a message yesterday that the checksum returned on some(all?) readback commands may not be clearing bit 8 before sending it back to the master controller. You should and the returned checksum with 0x7F before comparing it to your calculated checksum. I suspect we never got a call on this becasue most people ignore the returned checksum on read commands.

The first thing to do is to readback the version information for your roboclaw. That will give me a better idea what I'm looking at. The intent of the encoder OK bit was to confirm the CPLD on the older RoboClaws(green pcb) was functioning correctly. The Rev C roboclaws(red pcb) do not have a CPLD(the new CPU has built-in hardware decoding of quadrature pulses) so this bit was deprecated. I later adjusted the firmware on Rev C baords to set this bit so people wouldn't get confused by it but some of the first rev c boards will always show this bit as 0.

If you need any more help give me a call at our 800 number or you can email me(nathan@basicmicro.com).

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