C ceaser Active Member Licensed User Feb 24, 2009 #1 I wonder if somebody can help me. :sign0085: I want to build a little car which has a GPS and a processor with my software build into it. On the processor I will be able to store the horizontal alignment of the path that the car must follow. The software will get the coordinates from the GPS and convert this to a Stake Value and offset from the alignment line. In this way I will always know the distance that the car has travelled and how far away the car is from the alignment line. Can I send electric impulses to the RS232 port from my software to control the servo motors, which in turn will turn the wheels of my car so that it stays on track? Thanks Michael
I wonder if somebody can help me. :sign0085: I want to build a little car which has a GPS and a processor with my software build into it. On the processor I will be able to store the horizontal alignment of the path that the car must follow. The software will get the coordinates from the GPS and convert this to a Stake Value and offset from the alignment line. In this way I will always know the distance that the car has travelled and how far away the car is from the alignment line. Can I send electric impulses to the RS232 port from my software to control the servo motors, which in turn will turn the wheels of my car so that it stays on track? Thanks Michael
agraham Expert Licensed User Longtime User Feb 24, 2009 #2 ceaser said: Can I send electric impulses to the RS232 port from my software to control the servo motors, which in turn will turn the wheels of my car so that it stays on track?: Click to expand... In principle, yes you could drive two servos using the DTR and RTS pins. However if you are considering using the cheap standard RC type servos driven by a Basic4ppc program on a PDA then you will not be able to achieve the accuracy of pulse width required for these servos (1 to 2 mS wide with a resolution of about 5 to 10 uS) to control it properly nor the required frequency either (20 to 30 mS repetition rate) needed to keep the servo alive. You would probably need to interface to a dedicated microcontroller that would control the servos for you. I think that you will need the help of an experienced RC model hobbyist to stand a chance of getting anything working.
ceaser said: Can I send electric impulses to the RS232 port from my software to control the servo motors, which in turn will turn the wheels of my car so that it stays on track?: Click to expand... In principle, yes you could drive two servos using the DTR and RTS pins. However if you are considering using the cheap standard RC type servos driven by a Basic4ppc program on a PDA then you will not be able to achieve the accuracy of pulse width required for these servos (1 to 2 mS wide with a resolution of about 5 to 10 uS) to control it properly nor the required frequency either (20 to 30 mS repetition rate) needed to keep the servo alive. You would probably need to interface to a dedicated microcontroller that would control the servos for you. I think that you will need the help of an experienced RC model hobbyist to stand a chance of getting anything working.
Cableguy Expert Licensed User Longtime User Feb 24, 2009 #3 agraham said: In principle, yes you could drive two servos using the DTR and RTS pins. I think that you will need the help of an experienced RC model hobbyist to stand a chance of getting anything working. Click to expand... Google a bit for RS232 dc motor control and you will find lots of usefull info... dc motor are cheaper, and do not need any fancy electronics...Just a opto-isolator circuit to keep the RS232 from fying in the PDA side... try the ePanorama.net site...lots of info there, like this one..also the ELEKTOR magasine website has a lot of info on this subject... Power will be your main concern as motors are NOT power eficient... But in a nutshell....YES YOU CAN!!! Last edited: Feb 24, 2009
agraham said: In principle, yes you could drive two servos using the DTR and RTS pins. I think that you will need the help of an experienced RC model hobbyist to stand a chance of getting anything working. Click to expand... Google a bit for RS232 dc motor control and you will find lots of usefull info... dc motor are cheaper, and do not need any fancy electronics...Just a opto-isolator circuit to keep the RS232 from fying in the PDA side... try the ePanorama.net site...lots of info there, like this one..also the ELEKTOR magasine website has a lot of info on this subject... Power will be your main concern as motors are NOT power eficient... But in a nutshell....YES YOU CAN!!!
taximania Well-Known Member Licensed User Longtime User Feb 24, 2009 #4 @Ceaser www.taximania.net and have a look round the projects I've also got servo code for the PIC Ir to Pic -> PPC Bluetooth to Pic -> PPC Serial to Pic -> PPC GPS ?, oh yes, use port splitter and a lot of coding on the b4ppc side. Been there, done that, and got the t-shirt (English phrase :sign0161 Last edited: Feb 24, 2009
@Ceaser www.taximania.net and have a look round the projects I've also got servo code for the PIC Ir to Pic -> PPC Bluetooth to Pic -> PPC Serial to Pic -> PPC GPS ?, oh yes, use port splitter and a lot of coding on the b4ppc side. Been there, done that, and got the t-shirt (English phrase :sign0161
