From marksu at appistry.com Wed Jun 7 13:43:48 2006 From: marksu at appistry.com (Mark Sundt) Date: Wed Jun 21 14:08:33 2006 Subject: [WheelCommander] 3.3v Devices driving a Wheelcommander? Message-ID: <9012D2A498968848AFFB1AE58C3B7BB597E8D0@GONDOR.wave.local> Hi, I'm trying to drive a Nubotics Wheelcommander (serially) from a Parallax Propeller Demo board without much luck. I've calibrated the Wheelcommander using the Arconame USB/Serial device, and the Wheelcommander works fine from a BasicStamp demo board I have. So what I have tried so far is to - * Set the Wheelcommander communication speed to 9600 baud * Tested the Wheelcommander settings from a BasicStamp at 9600 baud. Works great.... * Create a SPIN (Propeller program) to drive a 9600 baud serial connection to a LCD panel (Tx only) * Successfully 'wrote' ASCII 'K' with a linefeed (also tried CR) to the LDC panel * Connected the Tx pin from the Wheelcommander to the pin I used with the LCD panel.. * Nothing... I'm thinking this has something to do with the 3.3v from the Propeller being able to drive the serial port of the Wheelcommander? Any help would be greatly appreciated! Thanks! Mark Background info - http://www.parallax.com/propeller/index.asp (Propeller Product Overview) http://forums.parallax.com/forums/default.aspx?f=25&m=113631 (Forum discussion on driving serial devices from a 3.3v devices, and specifically 'unverted signals'.. .) After using Jon Williams' debug object for awhile, I found that I needed something simpler yet: just a self-contained object that twiddled an output pin directly -- no inputs -- and provided an inverted signal that would drive my PC's RxD pin without additional circuitry. Here's the result: My PC works fine with the Propeller's 0 and 3.3V signal levels (in lieu of -10 and +10), but this may not work for everyone. From peters at nubotics.com Wed Jun 21 14:18:53 2006 From: peters at nubotics.com (Pete Skeggs) Date: Wed Jun 21 14:18:51 2006 Subject: [WheelCommander] 3.3v Devices driving a Wheelcommander? In-Reply-To: <9012D2A498968848AFFB1AE58C3B7BB597E8D0@GONDOR.wave.local> References: <9012D2A498968848AFFB1AE58C3B7BB597E8D0@GONDOR.wave.local> Message-ID: <4499B7BD.8060001@nubotics.com> Mark, I'm terribly sorry for not replying to your message. It got buried in a bunch of spam. Have you solved your problem yet? I'm wondering if you have tried connecting the LCD panel to your BasicStamp and verifying that you can communicate with that correctly? This would ensure that the polarity of the serial bit stream that the LCD expects is compatible with the BasicStamp, and is also thus compatible with the WheelCommander. By implication, this should verify that the Propeller's serial bit stream is compatible with both the LCD and the WheelCommander. My concern is that you have not tested all combinations (at least as of 6/7), so it is not clear if the Propeller's bit stream is of the correct polarity compared to what the WheelCommander wants. The WheelCommander needs uninverted, CMOS or TTL logic level signals, not +10/-10 RS232 signals (which are also inverted by definition). Let me know if this helps or if you have any other questions. Sincerely, Pete Skeggs Noetic Design, Inc. Mark Sundt wrote: >Hi, I'm trying to drive a Nubotics Wheelcommander (serially) from a >Parallax Propeller Demo board without much luck. >I've calibrated the Wheelcommander using the Arconame USB/Serial device, >and the Wheelcommander works fine from a BasicStamp demo board I have. >So what I have tried so far is to - > >* Set the Wheelcommander communication speed to 9600 baud >* Tested the Wheelcommander settings from a BasicStamp at 9600 >baud. Works great.... >* Create a SPIN (Propeller program) to drive a 9600 baud serial >connection to a LCD panel (Tx only) >* Successfully 'wrote' ASCII 'K' with a linefeed (also tried CR) >to the LDC panel >* Connected the Tx pin from the Wheelcommander to the pin I used >with the LCD panel.. >* Nothing... > > >I'm thinking this has something to do with the 3.3v from the Propeller >being able to drive the serial port of the Wheelcommander? > >Any help would be greatly appreciated! >Thanks! >Mark > >Background info - > >http://www.parallax.com/propeller/index.asp (Propeller Product Overview) > >http://forums.parallax.com/forums/default.aspx?f=25&m=113631 (Forum >discussion on driving serial devices from a 3.3v devices, and >specifically 'unverted signals'.. .) > >After using Jon Williams' debug object for awhile, I found that I needed >something simpler yet: just a self-contained object that twiddled an >output pin directly -- no inputs -- and provided an inverted signal that >would drive my PC's RxD pin without additional circuitry. Here's the >result: > >My PC works fine with the Propeller's 0 and 3.3V signal levels (in lieu >of -10 and +10), but this may not work for everyone. > > From evangelos.georgiou at kcl.ac.uk Wed Jun 21 17:06:34 2006 From: evangelos.georgiou at kcl.ac.uk (Evangelos Georgiou) Date: Wed Jun 21 17:07:00 2006 Subject: [WheelCommander] how does it work? In-Reply-To: <4499B7BD.8060001@nubotics.com> Message-ID: <000601c6958f$b9782ac0$0200a8c0@Tablet> Hi, I just bought the wheel commander and a set of encoders for my Mark III. I tried to run the configuration thing... but I keep getting calibration error 3... how to I fix this... I'm using GWS S03N 2BB and the servo is continuous rotation... is there a manual to use the software? Does anyone know where I should start to set up my servos with wheel commander? Thanks in advance. Angelo From plskeggs at noeticdesign.com Wed Jun 21 20:34:11 2006 From: plskeggs at noeticdesign.com (Pete Skeggs) Date: Wed Jun 21 20:34:25 2006 Subject: [WheelCommander] how does it work? In-Reply-To: <000601c6958f$b9782ac0$0200a8c0@Tablet> References: <000601c6958f$b9782ac0$0200a8c0@Tablet> Message-ID: <449A0FB3.8090704@noeticdesign.com> Angelo, > Hi, I just bought the wheel commander and a set of encoders for my Mark III. I > tried to run the configuration thing... but I keep getting calibration error > 3... how to I fix this... I'm using GWS S03N 2BB and the servo is continuous > rotation... is there a manual to use the software? There is not yet a software manual, only the user manual for the WheelCommander: http://www.nubotics.com/products/wc132/WC-132-product_manual.pdf See pages 22-28, the table of Calibration Error Codes on page 11, and the FAQ here: http://www.nubotics.com/support/wcfaq.html. Error 3 means "failed to find servo zero motion position." This occurs when the WC-132 tries to determine what pulsewidth value, when sent to the servo, results in it not spinning (or spinning very slowly), but it fails to find a good value within a timeout period. This can occur if a servo has a damaged circuit board inside of it. This kind of damage occurs when the servo is powered by a supply of a (much) higher voltage than the 6.0 volts the servo is designed for. Other times, the servo is just bad. Since you own a MarkIII, have you tried the servos with the MarkIII controller without the WC-132? You might try running one of the servo calibration routines on the MinisumoMarkIII yahoogroup to make sure that the servos can indeed be made to not spin. This can also occur if the batteries are either low or weak. Check each cell with a volt meter and make sure they all read roughly the same voltage, and that the total supply is above 5 volts or so. If the servo supply is much below that, or if the current is limited due to a bad cell or even a poor electrical connection on the servo supply pins of the PCB, the servos will not behave correctly. Let me know if this helps, or if not, what your results are. Sincerely, Pete Skeggs Nubotics Tech Support From evangelos.georgiou at kcl.ac.uk Thu Jun 22 00:47:39 2006 From: evangelos.georgiou at kcl.ac.uk (Evangelos Georgiou) Date: Thu Jun 22 00:48:25 2006 Subject: [WheelCommander] how does it work? In-Reply-To: <449A0FB3.8090704@noeticdesign.com> Message-ID: <000301c695d0$2306eb30$e6324989@adminsystems.adm.kcl.ac.uk> Dear Pete, Thank you so much for your detailed e-mail. I came to the same conclusions. I've tried the servos on the ooPic board that comes with Mark III and they work fine. It's really strange... I was wondering if you could recommend a servo that works well with wheel commander? Thanks so much for your help, Angelo -----Original Message----- From: wheelcommander-bounces@list.nubotics.com [mailto:wheelcommander-bounces@list.nubotics.com] On Behalf Of Pete Skeggs Sent: 22 June 2006 04:34 To: WC-132 WheelCommander Controller Support List Subject: Re: [WheelCommander] how does it work? Angelo, > Hi, I just bought the wheel commander and a set of encoders for my Mark III. I > tried to run the configuration thing... but I keep getting calibration error > 3... how to I fix this... I'm using GWS S03N 2BB and the servo is continuous > rotation... is there a manual to use the software? There is not yet a software manual, only the user manual for the WheelCommander: http://www.nubotics.com/products/wc132/WC-132-product_manual.pdf See pages 22-28, the table of Calibration Error Codes on page 11, and the FAQ here: http://www.nubotics.com/support/wcfaq.html. Error 3 means "failed to find servo zero motion position." This occurs when the WC-132 tries to determine what pulsewidth value, when sent to the servo, results in it not spinning (or spinning very slowly), but it fails to find a good value within a timeout period. This can occur if a servo has a damaged circuit board inside of it. This kind of damage occurs when the servo is powered by a supply of a (much) higher voltage than the 6.0 volts the servo is designed for. Other times, the servo is just bad. Since you own a MarkIII, have you tried the servos with the MarkIII controller without the WC-132? You might try running one of the servo calibration routines on the MinisumoMarkIII yahoogroup to make sure that the servos can indeed be made to not spin. This can also occur if the batteries are either low or weak. Check each cell with a volt meter and make sure they all read roughly the same voltage, and that the total supply is above 5 volts or so. If the servo supply is much below that, or if the current is limited due to a bad cell or even a poor electrical connection on the servo supply pins of the PCB, the servos will not behave correctly. Let me know if this helps, or if not, what your results are. Sincerely, Pete Skeggs Nubotics Tech Support _______________________________________________ WheelCommander mailing list WheelCommander@list.nubotics.com http://list.nubotics.com/mailman/listinfo/wheelcommander Nubotics Website: http://www.nubotics.com