Society of Robots - Robot Forum

Electronics => Electronics => Topic started by: bsamuels on February 03, 2010, 11:09:07 PM

Title: How to use this servo transmitter for motors?
Post by: bsamuels on February 03, 2010, 11:09:07 PM
I've got a robot that is going to use two motors that will be user controlled wirelessly. The controller is a joystick with 2 pots, and the transmitter I want to use is  one of these http://www.servocity.com/html/neon_fm_systems.html (http://www.servocity.com/html/neon_fm_systems.html) however it outputs two channels of square waves, and only one channel of analog wave(i think that's what it's called) which can be used to power one motor. I was wondering if there is any way I could bypass whatever circuit it is that converts the analog pot reading to a square wave, or if not what other transmitter can I use?
Title: Re: How to use this servo transmitter for motors?
Post by: Razor Concepts on February 03, 2010, 11:38:31 PM
You can use an ESC - electronic speed control. Automatically takes the pulse and uses it to control motors.
Title: Re: How to use this servo transmitter for motors?
Post by: Soeren on February 04, 2010, 08:02:19 PM
Hi,

[...] I want to use is  one of these http://www.servocity.com/html/neon_fm_systems.html (http://www.servocity.com/html/neon_fm_systems.html) however it outputs two channels of square waves, and only one channel of analog wave(i think that's what it's called) which can be used to power one motor. I was wondering if there is any way I could bypass whatever circuit it is that converts the analog pot reading to a square wave, or if not what other transmitter can I use?
There's nothing to bypass. Don't buy this transmitter, it's not worth your money.
It has got only one proportional channel, the stick is probably just using one proportional channel (2 at most, but I doubt that) but it is by switches that couples different value resistors into the circuit to transmit like one proportional channel held at one out of four positions.
Same junk as cheap R/C toycars.

No intermediate speeds on such a beast (except if you use the proportional channel) and the steering is bang-bang, full left, full right or straight ahead.
One wonders why they sell such rubbish, when the production cost is about the same whether they make it fully proportional or not.
Title: Re: How to use this servo transmitter for motors?
Post by: bsamuels on February 04, 2010, 10:15:42 PM
Hi,

[...] I want to use is  one of these http://www.servocity.com/html/neon_fm_systems.html (http://www.servocity.com/html/neon_fm_systems.html) however it outputs two channels of square waves, and only one channel of analog wave(i think that's what it's called) which can be used to power one motor. I was wondering if there is any way I could bypass whatever circuit it is that converts the analog pot reading to a square wave, or if not what other transmitter can I use?
There's nothing to bypass. Don't buy this transmitter, it's not worth your money.
It has got only one proportional channel, the stick is probably just using one proportional channel (2 at most, but I doubt that) but it is by switches that couples different value resistors into the circuit to transmit like one proportional channel held at one out of four positions.
Same junk as cheap R/C toycars.

No intermediate speeds on such a beast (except if you use the proportional channel) and the steering is bang-bang, full left, full right or straight ahead.
One wonders why they sell such rubbish, when the production cost is about the same whether they make it fully proportional or not.


I got this one from a dumpster, so I already sorta have it. I know it broadcasts the stick on two channels because I tested it with a 3 channel receiver. If I can't program ESC's to interpret the servo wave as a proportional wave, what is my best course of action?


Quote
You can use an ESC - electronic speed control. Automatically takes the pulse and uses it to control motors.
Do you have any good sources for programmable ESC's? After a quick google I have found out that there is not much background info on them or sources to buy them from.
Title: Re: How to use this servo transmitter for motors?
Post by: Razor Concepts on February 04, 2010, 10:43:36 PM
They aren't really "programmable" in the robotics sense, since the majority are just for RC cars. Dimension Engineering has some nice Sabertooth speed controllers more geared towards robotics, might want to check those out.