Need DIY Transmitter & Receiver Plans

HumanoidoHumanoido Posts: 5,770
edited October 2011 in Propeller 1 Vote Up0Vote Down
with the following requirements:
  1. Simple DIY connects to Propeller chip
  2. Very light weight
  3. Tiny physical size
  4. A circuit with almost no parts
  5. Uses common easy to find parts
  6. Range about 10 or 12 feet
  7. Simple software
The purpose is to connect the transmitter to a Propeller chip and send it up, by rocket, into Micro Space (about 10 feet high). During this time, the Propeller will read a Parallax accelerometer and feed the telemetry info to transmitter. The transmitter will send as much continuous data as possible in real time during a two second flight. The receiver is connected to another Propeller chip and holds the data, then stores the data after flight for later playback.
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Comments

  • 16 Comments sorted by Date Added Votes
  • Mike GMike G Posts: 2,702
    edited October 2011 Vote Up0Vote Down
    Why not just store the data in RAM on the Prop chip that goes up in the rocket.
    Any fool can make something complicated. It takes a genius to make it simple. Woody Guthrie
  • HumanoidoHumanoido Posts: 5,770
    edited October 2011 Vote Up0Vote Down
    Mike G wrote: »
    Why not just store the data in RAM on the Prop chip that goes up in the rocket.
    There is a version being developed that does just that, however for this experiment the rocket is treated as non-recoverable.
  • ChrisGaddChrisGadd Posts: 214
    edited October 2011 Vote Up0Vote Down
    What kind of bandwidth are you looking for? The prop itself is capable of producing a 120MHz signal, shouldn't need much of an amplifier to transmit 12 feet, a 1/4 wavelength antenna is about 2 feet at 120MHz, use simple on/off keying ... I think it could be done.
  • Mike GreenMike Green Posts: 21,987
    edited October 2011 Vote Up0Vote Down
    Over that sort of range, I'd use IR. On the Prop end, you'd just need two LEDs (to get a broad "beam") along with their series resistors to limit total current to about 30mA. A cog counter could be used to make the 38KHz carrier which you could switch on and off. You could use a Simple_Serial object (slightly modified) to send the data. Rather than controlling OUTA, it would control DIRA to switch the I/O pin from output to input. On the launchpad end, you'd have a standard modulated IR detector hooked up to another Prop. You'd need to keep the Baud slow (maybe 1200 or 2400 Baud) and use a lot of error checking and redundancy in the data.
  • Ray0665Ray0665 Posts: 222
    edited October 2011 Vote Up0Vote Down
    Check out my Sure Electronics GP-GC010v1 / CY2196R 433Mhz driver/demo in the OBEX the transceivers are available for about $10 each
    A poor workman always blames his tools - Ray
  • HumanoidoHumanoido Posts: 5,770
    edited October 2011 Vote Up0Vote Down
    ChrisGadd wrote: »
    What kind of bandwidth are you looking for? The prop itself is capable of producing a 120MHz signal, shouldn't need much of an amplifier to transmit 12 feet, a 1/4 wavelength antenna is about 2 feet at 120MHz, use simple on/off keying ... I think it could be done.
    Another good idea. I tried searching for the link but the search engine didn't bring it up. Any idea where the propeller to transmit forum link is located?
  • HumanoidoHumanoido Posts: 5,770
    edited October 2011 Vote Up0Vote Down
    Mike Green wrote: »
    Over that sort of range, I'd use IR. On the Prop end, you'd just need two LEDs (to get a broad "beam") along with their series resistors to limit total current to about 30mA. A cog counter could be used to make the 38KHz carrier which you could switch on and off. You could use a Simple_Serial object (slightly modified) to send the data. Rather than controlling OUTA, it would control DIRA to switch the I/O pin from output to input. On the launchpad end, you'd have a standard modulated IR detector hooked up to another Prop. You'd need to keep the Baud slow (maybe 1200 or 2400 Baud) and use a lot of error checking and redundancy in the data.
    This is a very good idea. It sounds like a Penguin robot program I made some time ago that does exactly this function. Too bad I can't directly convert BS2px PBASIC code into Spin. However, as I recall, the range of the on-board IR transmitter receiver was around 6 or 7-feet.
  • HumanoidoHumanoido Posts: 5,770
    edited October 2011 Vote Up0Vote Down
    Ray0665 wrote: »
    Check out my Sure Electronics GP-GC010v1 / CY2196R 433Mhz driver/demo in the OBEX the transceivers are available for about $10 each
    Good idea. I wonder if the transceiver and two boards would end up totaling too much weight for the rocket. The rocket payload weight expectedly cannot exceed approximately one Propeller chip, a tiny cell battery and a few tiny components.

    This is a demo of the Sure Electronics GP-GC010v1 433Mhz Transceiver (CY2196R) It is a block Send/Receive with checksum, all in Spin. Two Transceivers and two propeller boards are required to use these modules. Board A creates, sends, receives and displays a packet. Board B retransmits any packet it receives with a small modification for demo purposes.
  • Ray0665Ray0665 Posts: 222
    edited October 2011 Vote Up0Vote Down
    The demo needed two setups (obviously) because I implemented a master send, slave echo, master receive, kind of approach.
    The rocket/ground setup only needs a send on one side and receive on the other (and the transceiver module is quite small).

    The heart of my demo, is/are the two Block send /receive routines augmented with a few utility routines.

    As setup here it is kinda slow at only 19.2 K baud. The data on these modules is very sparse but it does mention a faster baud rate setting but I do not know how to set that. Everything I learned about these modules was found by experimentation.
    A poor workman always blames his tools - Ray
  • Ray0665Ray0665 Posts: 222
    edited October 2011 Vote Up0Vote Down
    Here is the data sheet on the module such as it is
    http://www.sure-electronics.net/rf,audio/GP-GC010.pdf

    ***** Use the wiring diagram and pin outs from my demo module not from the data sheet ****

    To clarify my comment about being slow --
    I think at 19200 baud you can get 37 packets per second out of this setup
    19200 baud / (8 bits per byte * 64 bytes) ~ 37 packets per second

    Hope this helps


    Post edit
    I have attached the stripped packet send/receive modules if you want them

    Post edit 2
    Updated packet send/receive to remove unused led module and add keep alive variable
    A poor workman always blames his tools - Ray
  • Duane DegnDuane Degn Posts: 9,084
    edited October 2011 Vote Up0Vote Down
    Humanoido,

    These will provide two way communication (up to 2Mbps). They cost less than $7 each.

    I wrote a driver for the Propeller.

    Duane
  • Mike GreenMike Green Posts: 21,987
    edited October 2011 Vote Up0Vote Down
    About using IR ... The Prop can handle higher I/O pin current loads than the Stamps. The Stamp pins are rated around 25mA. The Propeller pins can handle up to about 40mA. Given that a standard TV remote control can work over distances on the order of 10-12 feet, you ought to be able to get a small amount of data over that distance as well.
  • HumanoidoHumanoido Posts: 5,770
    edited October 2011 Vote Up0Vote Down
    Thanks everyone! Lots of excellent options here!
  • Cluso99Cluso99 Posts: 10,826
    edited October 2011 Vote Up0Vote Down
    Humanoido: Dr_Acula uses radio modules for comms between his cpm modules and they are very reliable. Perhaps you could PM him as he may not read this thread.
    My Prop boards: CpuBlade, TriBlade, RamBlade, www.clusos.com
    Prop Tools (Index)
    Emulators (Index) ZiCog (Z80)
    Prop OS (also see Sphinx, PropDos, PropCmd)
  • dr hydradr hydra Posts: 185
    edited October 2011 Vote Up0Vote Down
    Using IR...can you use the full duplex object to send information between two propeller..I am thinking of a distance of about 5 to 6 feet and only one way communcaiton (client/server)... Would I need to modify the spin/PASM objects...Baud 38400...right
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