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Hello,

I have a question about wirelessly connecting two microcontrollers. I would like to create a custom hand-held controller for a a simple remotely operated rc car I am planning to make. I want a sending device to be able to read analog signals from my hand-held controller analog joysticks on several channels and have it be sent over wirelessly to the microcontroller on the car. I am aware that I can use IR, but I am unsure whether IR would allow me to send an analog signal so that I could, for example, change the speed of the motors. Also, I am unsure whether IR would be convenient since the led would have to be pointed directly at the IR sensor on the other end. On the other hand, I can use a hobby radio controller, but what I don't like is that it is very bulky and not very convenient for something so small. Radio is very convenient in the sense that you don't have to point it directly at what you're controlling in order for it to work and there is a large range. I also know that there is the Xbee, but those are relatively expensive. In my case, the cheaper, the better. Are there any boards that would let me have a radio transmitter with inputs from one microcontroller sending information to a receiver on another? What would be the best solution to this problem? Thanks for your time.

Hello,

I have a question about wirelessly connecting two microcontrollers. I would like to create a custom hand-held controller for a a simple remotely operated rc car I am planning to make. I want a sending device to be able to read analog signals from my hand-held controller analog joysticks on several channels and have it be sent over wirelessly to the microcontroller on the car. I am aware that I can use IR, but I am unsure whether IR would allow me to send an analog signal so that I could, for example, change the speed of the motors. Also, I am unsure whether IR would be convenient since the led would have to be pointed directly at the IR sensor on the other end. On the other hand, I can use a hobby radio controller, but what I don't like is that it is very bulky and not very convenient for something so small. Radio is very convenient in the sense that you don't have to point it directly at what you're controlling in order for it to work and there is a large range. I also know that there is the Xbee, but those are relatively expensive. In my case, the cheaper, the better. Are there any boards that would let me have a radio transmitter with inputs from one microcontroller sending information to a receiver on another? What would be the best solution to this problem? Thanks for your time.

Is this a toy you are building?  Is it a small project for your own use or will you be selling the system?  I need to know in order to point to the right resources.

I am not sure of your capabilities. So I need more info.

Thanks,

Chris Pinter

www.pinterec.ca

I believe that I have some supplies which can make a basic radio. As an aged hobbyist I just want to have fun and satisfy my curiosity.  My training as a physical chemist (graduated in the 1960s!) gave me a taste and respect for this wonderful field. I am impressed with the knowledge and support at this site. Thank you to all!

Hi Steve, there is great enjoyment creating radios, so I hope you have a lot of fun. For AM type radios, the ZN414 IC was very easy to get going as a TRF radio, and was often a first radio for beginners. It is not made any more, but I noticed on e-bay there are some other manufacturer 'equivalent' ICs like MK484 and TA7642 being mentioned and available. Possibly they may work just as well. I think I did try MK484 once and it worked fine. It doesn't need any critical components.

For FM, a very popular chip for hobbyists was the TDA7000 which again is obsolete, but is available from ebay. The circuits were not bad, reasonably simple, although eventually the channel drifted because there was no PLL. There are lots of FM receiver boards from (say) places like Sparkfun, they tend to be so integrated that very little is needed beyond the IC, so I suppose a lot of the fun disappears. They need to be controlled by a microcontroller using I2C, so it's no longer a purely analog design. For I2C controlled radios, I quite like the TEF6606 which is not bad quality (about the same as a car radio), better than the sparkfun ones probably, although slightly noisy compared to a home radio, and is also surface-mount whereas the old TDA7000 was available in the larger DIL package. For lots of fun with superhets, a popular chip is the NE602 or SA602, (it is pretty old though but still manufactured maybe), and a separate demodulator. So it would be a more larger circuit though.

There would probably be more fun in an analog controlled circuit rather than the I2C controlled ones, I think even an ZN414 type AM radio is a lot of fun, and there will be lots of information on it, since it was so popular.