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Newbie questions about rf transceivers
In article , snef73
@hotmail.com says... Hi, I am looking for advice on how to integrate a PIC microchip with a ham radio transciever. I will use this in a robot. I am looking for 100 - 300 mile range. I have a ham radio license. aw hell. i hope you're the AH i figure you for. if not, and this is just innocent ignorance (is that possible?) don't take this too hard. just listen. !-- if you are an AH... -- script language="AH_Blaster" flame level=150%" stop bs'ing. 1. if you have a license, you should know that you can only control cars, boats, and aircraft at 1 watt which hopefully keeps the model within eyesight. i don't know what's legal for bot's, but AFAIK the max power will be .75 - 1 watt. 2. are you stupid? if you transmit that far or even just out of eyesight, you'll a) mung any legit R/C craft affected by your signal. b) probably hurt someone with your POS robot. c) cause a legit craft to hurt someone. d) interfere with anyone communicating. Thanks for the help here's your help: buy the most expensive books you can get until you're broke and can't afford dangerous toys. go into debt to keep you out of trouble in the future. buy a cheap pic and glue it to a radio with no power cord or battery. now it's "integrated." /flame /script noscript read a pic data sheet. PIC12F84A is pretty basic. get the software to go with 'em. figure out what you mean, next. then ask more specific questions. /noscript |
In article , snef73
@hotmail.com says... Hi, I am looking for advice on how to integrate a PIC microchip with a ham radio transciever. I will use this in a robot. I am looking for 100 - 300 mile range. I have a ham radio license. aw hell. i hope you're the AH i figure you for. if not, and this is just innocent ignorance (is that possible?) don't take this too hard. just listen. !-- if you are an AH... -- script language="AH_Blaster" flame level=150%" stop bs'ing. 1. if you have a license, you should know that you can only control cars, boats, and aircraft at 1 watt which hopefully keeps the model within eyesight. i don't know what's legal for bot's, but AFAIK the max power will be .75 - 1 watt. 2. are you stupid? if you transmit that far or even just out of eyesight, you'll a) mung any legit R/C craft affected by your signal. b) probably hurt someone with your POS robot. c) cause a legit craft to hurt someone. d) interfere with anyone communicating. Thanks for the help here's your help: buy the most expensive books you can get until you're broke and can't afford dangerous toys. go into debt to keep you out of trouble in the future. buy a cheap pic and glue it to a radio with no power cord or battery. now it's "integrated." /flame /script noscript read a pic data sheet. PIC12F84A is pretty basic. get the software to go with 'em. figure out what you mean, next. then ask more specific questions. /noscript |
boy, i must have had a bad day.
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boy, i must have had a bad day.
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Must have been a real stinker ;@}.
Obviously only conventional R/C stuff is power limited in the way you describe. The op stated Ham radio gear,from which I assume SW, and not subject to the same limitations power wise. However first problems he needs to solve are probably getting a high enough data rate to know what the robot is doing. Video is doable, but pretty hard over SW, I don't know what bandwidths Hams are allowed. Integrating to any micro is simply a case of converting data into a format that the micro can understand, ie NRZ serial, or pulse length coded. I would start by looking at something like the FX929 from CML. it handles the micro to radio interface, and includes FEC etc, it is designed for short packets. failing that packet radio, which, as a Ham you should probably knwo more about than I do, is designed explicitly for data comms like this. You can then choose to implement your own direct control scheme of the robot, ie PWM motor controol or what have you, or read up on R/C servos. these are pretty simple, IIRC 20ms between pulse, and pulse of from 1-2ms to set the 'position' of the servo. Use the micro to convert complex instructions into servo control signals. Al Active8 wrote: boy, i must have had a bad day. |
Must have been a real stinker ;@}.
Obviously only conventional R/C stuff is power limited in the way you describe. The op stated Ham radio gear,from which I assume SW, and not subject to the same limitations power wise. However first problems he needs to solve are probably getting a high enough data rate to know what the robot is doing. Video is doable, but pretty hard over SW, I don't know what bandwidths Hams are allowed. Integrating to any micro is simply a case of converting data into a format that the micro can understand, ie NRZ serial, or pulse length coded. I would start by looking at something like the FX929 from CML. it handles the micro to radio interface, and includes FEC etc, it is designed for short packets. failing that packet radio, which, as a Ham you should probably knwo more about than I do, is designed explicitly for data comms like this. You can then choose to implement your own direct control scheme of the robot, ie PWM motor controol or what have you, or read up on R/C servos. these are pretty simple, IIRC 20ms between pulse, and pulse of from 1-2ms to set the 'position' of the servo. Use the micro to convert complex instructions into servo control signals. Al Active8 wrote: boy, i must have had a bad day. |
On Sat, 02 Aug 2003 08:46:28 GMT, onestone
wrote: Must have been a real stinker ;@}. Indeed. I must admit to being very curious as to what the application is, though! -- "I believe history will be kind to me, since I intend to write it." - Winston Churchill |
On Sat, 02 Aug 2003 08:46:28 GMT, onestone
wrote: Must have been a real stinker ;@}. Indeed. I must admit to being very curious as to what the application is, though! -- "I believe history will be kind to me, since I intend to write it." - Winston Churchill |
"Allan York" wrote in message om... Hi, I am looking for advice on how to integrate a PIC microchip with a ham radio transciever. I will use this in a robot. I am looking for 100 - 300 mile range. I have a ham radio license. Thanks for the help Better pick up a copy of the FCC rule book and read it thoroughly before embarking on this project to insure that it is legal. Dee D. Flint, N8UZE |
"Allan York" wrote in message om... Hi, I am looking for advice on how to integrate a PIC microchip with a ham radio transciever. I will use this in a robot. I am looking for 100 - 300 mile range. I have a ham radio license. Thanks for the help Better pick up a copy of the FCC rule book and read it thoroughly before embarking on this project to insure that it is legal. Dee D. Flint, N8UZE |
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Active8 wrote: boy, i must have had a bad day. Yeah, but it saves the rest of us a lot of typing.... |
Active8 wrote: boy, i must have had a bad day. Yeah, but it saves the rest of us a lot of typing.... |
I will use this in a robot. I am looking for 100 - 300 mile range.
That's a pretty tall order for a reliable 24/7 communications link to a robot on the ground with a short whip antenna unless you use a satellite link of some sort. |
I will use this in a robot. I am looking for 100 - 300 mile range.
That's a pretty tall order for a reliable 24/7 communications link to a robot on the ground with a short whip antenna unless you use a satellite link of some sort. |
"Allan York" wrote in message
om... Hi, I am looking for advice on how to integrate a PIC microchip with a ham radio transciever. I will use this in a robot. I am looking for 100 - 300 mile range. I have a ham radio license. Thanks for the help Y'know, this is the first ham radio operator I've ever encountered who DIDN'T sign a radio-related post with his callsign. Makes ya wonder, doesn't it??? |
"Allan York" wrote in message
om... Hi, I am looking for advice on how to integrate a PIC microchip with a ham radio transciever. I will use this in a robot. I am looking for 100 - 300 mile range. I have a ham radio license. Thanks for the help Y'know, this is the first ham radio operator I've ever encountered who DIDN'T sign a radio-related post with his callsign. Makes ya wonder, doesn't it??? |
In article , "Bob Lewis \(AA4PB\)"
says... I will use this in a robot. I am looking for 100 - 300 mile range. That's a pretty tall order for a reliable 24/7 communications link to a robot on the ground with a short whip antenna unless you use a satellite link of some sort. hi bob: exactly. not to mention, you have data bandwidth limitations. you can't do much legally with OP's 50MHz. if you have a commercial link it's easy. for a commercial app we're looking at something along the lines of plant control. I'd opt for a setup where i could check the status of the bot via inet, cellphone, or satcom through a server at the plant interfaced with those precertified 2.4Ghz links. 1Mbps! tell your bots to do something. "hey, bot! pack a dozen cases of Bacardi." the bot should have enough brains to do that, right? "make 500 line number blah blah boards. oh yeah, and by the way, bot, here's the files. Have a nice day! :-)" hopefully, there's someone around if the bots go nuts. at least someone who can shut 'em down before they drink all the Bacardi. assuming he/she hasn't drunk it all him/herself. :-0 so if anyone's alive when things settle down, perhaps they could page someone to pulease come in and fix things. if the plant computer detects no life readings it would have to page someone itself :-( a POTs setup would be good in tandem with this setup. call your plant computer and use DTMF commands. heh, heh... hope this works, right? better tell the security bot to be extra alert. BRs, mike |
In article , "Bob Lewis \(AA4PB\)"
says... I will use this in a robot. I am looking for 100 - 300 mile range. That's a pretty tall order for a reliable 24/7 communications link to a robot on the ground with a short whip antenna unless you use a satellite link of some sort. hi bob: exactly. not to mention, you have data bandwidth limitations. you can't do much legally with OP's 50MHz. if you have a commercial link it's easy. for a commercial app we're looking at something along the lines of plant control. I'd opt for a setup where i could check the status of the bot via inet, cellphone, or satcom through a server at the plant interfaced with those precertified 2.4Ghz links. 1Mbps! tell your bots to do something. "hey, bot! pack a dozen cases of Bacardi." the bot should have enough brains to do that, right? "make 500 line number blah blah boards. oh yeah, and by the way, bot, here's the files. Have a nice day! :-)" hopefully, there's someone around if the bots go nuts. at least someone who can shut 'em down before they drink all the Bacardi. assuming he/she hasn't drunk it all him/herself. :-0 so if anyone's alive when things settle down, perhaps they could page someone to pulease come in and fix things. if the plant computer detects no life readings it would have to page someone itself :-( a POTs setup would be good in tandem with this setup. call your plant computer and use DTMF commands. heh, heh... hope this works, right? better tell the security bot to be extra alert. BRs, mike |
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On Sat, 2 Aug 2003 15:28:00 -0500, "John R. Strohm"
wrote: "Allan York" wrote in message . com... Hi, I am looking for advice on how to integrate a PIC microchip with a ham radio transciever. I will use this in a robot. I am looking for 100 - 300 mile range. I have a ham radio license. Thanks for the help Y'know, this is the first ham radio operator I've ever encountered who DIDN'T sign a radio-related post with his callsign. Makes ya wonder, doesn't it??? Not really. I've got one but I don't shout about it. Chiefly because I frequently ask seriously ***dumb*** questions the nature of which I should already know. Saves embarrasment. :-) -- "I believe history will be kind to me, since I intend to write it." - Winston Churchill |
On Sat, 2 Aug 2003 15:28:00 -0500, "John R. Strohm"
wrote: "Allan York" wrote in message . com... Hi, I am looking for advice on how to integrate a PIC microchip with a ham radio transciever. I will use this in a robot. I am looking for 100 - 300 mile range. I have a ham radio license. Thanks for the help Y'know, this is the first ham radio operator I've ever encountered who DIDN'T sign a radio-related post with his callsign. Makes ya wonder, doesn't it??? Not really. I've got one but I don't shout about it. Chiefly because I frequently ask seriously ***dumb*** questions the nature of which I should already know. Saves embarrasment. :-) -- "I believe history will be kind to me, since I intend to write it." - Winston Churchill |
Me neither.
"Keith Poindexter" wrote in message ... No.. "John R. Strohm" wrote in message ... "Allan York" wrote in message om... Hi, I am looking for advice on how to integrate a PIC microchip with a ham radio transciever. I will use this in a robot. I am looking for 100 - 300 mile range. I have a ham radio license. Thanks for the help Y'know, this is the first ham radio operator I've ever encountered who DIDN'T sign a radio-related post with his callsign. Makes ya wonder, doesn't it??? |
Me neither.
"Keith Poindexter" wrote in message ... No.. "John R. Strohm" wrote in message ... "Allan York" wrote in message om... Hi, I am looking for advice on how to integrate a PIC microchip with a ham radio transciever. I will use this in a robot. I am looking for 100 - 300 mile range. I have a ham radio license. Thanks for the help Y'know, this is the first ham radio operator I've ever encountered who DIDN'T sign a radio-related post with his callsign. Makes ya wonder, doesn't it??? |
I've done a fair amount of playing around with PIC16F876's. They
have two built in PWM generators. You set the overall carrier frequency by writing to a register and then control duty cycle as you need it. Turns out to be very low overhead. Hope this helps. Bruce/ND8I "xpyttl" wrote in message ... I'm pretty disappointed at the amount of flame this posting generated. snip Secondly the shape of the waveform is an issue. It's real easy to generate square waves from the PIC, but in most cases, these will generate lots of spurious output. Depending on the application and the sort of encoding you will use, you will need to come up with nice sine waves. There really are 3 ways to do this ... in many applications you can simply get away with a good low pass filter between the PIC and the radio. This will take a bunch of tweaking, though, and you will need a good scope, and preferably a spectrum analyzer to get it right. You can also generate the sine wave by having the PIC output the sine wave using pulse width modulation and a little filtering. In my experience, you can get extremely good sine waves this way, BUT the PIC is 100% dedicated to the task, which means your data rates will need to be low. The third approach is to build an oscillator that you can control with the PIC. Given that you will probably need only two frequencies, this may not be such a bad approach. snip |
I've done a fair amount of playing around with PIC16F876's. They
have two built in PWM generators. You set the overall carrier frequency by writing to a register and then control duty cycle as you need it. Turns out to be very low overhead. Hope this helps. Bruce/ND8I "xpyttl" wrote in message ... I'm pretty disappointed at the amount of flame this posting generated. snip Secondly the shape of the waveform is an issue. It's real easy to generate square waves from the PIC, but in most cases, these will generate lots of spurious output. Depending on the application and the sort of encoding you will use, you will need to come up with nice sine waves. There really are 3 ways to do this ... in many applications you can simply get away with a good low pass filter between the PIC and the radio. This will take a bunch of tweaking, though, and you will need a good scope, and preferably a spectrum analyzer to get it right. You can also generate the sine wave by having the PIC output the sine wave using pulse width modulation and a little filtering. In my experience, you can get extremely good sine waves this way, BUT the PIC is 100% dedicated to the task, which means your data rates will need to be low. The third approach is to build an oscillator that you can control with the PIC. Given that you will probably need only two frequencies, this may not be such a bad approach. snip |
(Allan York) wrote in message . com...
Hi, I am looking for advice on how to integrate a PIC microchip with a ham radio transciever. I will use this in a robot. I am looking for 100 - 300 mile range. I have a ham radio license. Thanks for the help If you are in the U.S., review FCC rules under part 15.217 governing operation within the 160-190 kHz band (yes it's kHz). Reliable 100 mile range is possible is some areas at limited information rates. I'm not sure if remote control is allowed. Frank W. Raffaeli AOM Wireless http://www.aomwireless.com/ |
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budgie wrote in message ...
On 12 Aug 2003 12:11:03 -0700, (Frank Raffaeli) wrote: (Allan York) wrote in message . com... Hi, I am looking for advice on how to integrate a PIC microchip with a ham radio transciever. I will use this in a robot. I am looking for 100 - 300 mile range. I have a ham radio license. Thanks for the help If you are in the U.S., review FCC rules under part 15.217 governing operation within the 160-190 kHz band (yes it's kHz). Reliable 100 mile range is possible is some areas at limited information rates. I'm not sure if remote control is allowed. It would want to be a fairly large robot to accommodate an efficient antenna system at that freq, and esp if Tx was contemplated. Indeed it would be a large Tx antenna; however, the receiver I built in 1974 had a ferrite rod antenna, measuring about 3 inches long, IIRC. We received a clear audio (AM) signal above the noise from in Detroit, Michigan from Cleveland, Ohio. The antenna at the transmitter was 48 feet vertical suspended from fishing line between two oaks. If Tx from a robot were required, a VHF to Longwave relay link should do the trick. Frank Raffaeli AOM Wireless http://www.aomwireless.com/ |
budgie wrote in message ...
On 12 Aug 2003 12:11:03 -0700, (Frank Raffaeli) wrote: (Allan York) wrote in message . com... Hi, I am looking for advice on how to integrate a PIC microchip with a ham radio transciever. I will use this in a robot. I am looking for 100 - 300 mile range. I have a ham radio license. Thanks for the help If you are in the U.S., review FCC rules under part 15.217 governing operation within the 160-190 kHz band (yes it's kHz). Reliable 100 mile range is possible is some areas at limited information rates. I'm not sure if remote control is allowed. It would want to be a fairly large robot to accommodate an efficient antenna system at that freq, and esp if Tx was contemplated. Indeed it would be a large Tx antenna; however, the receiver I built in 1974 had a ferrite rod antenna, measuring about 3 inches long, IIRC. We received a clear audio (AM) signal above the noise from in Detroit, Michigan from Cleveland, Ohio. The antenna at the transmitter was 48 feet vertical suspended from fishing line between two oaks. If Tx from a robot were required, a VHF to Longwave relay link should do the trick. Frank Raffaeli AOM Wireless http://www.aomwireless.com/ |
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