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Eb500 with PIC16 — Parallax Forums

Eb500 with PIC16

mayaimayai Posts: 8
edited 2010-02-03 03:36 in Robotics
hello recently i just purchased eb500, to make this simple.. how does i connect it with PIC and what is the pin needed to be use...
Thanks..blush.gif

Comments

  • Mike GreenMike Green Posts: 23,101
    edited 2010-01-19 04:50
    Here is a link to the EB500 documentation: www.parallax.com/dl/docs/prod/comm/eb500.pdf.

    You'll have to figure out how to connect it to a PIC and how to program the PIC to communicate with the EB500. As noted in the documentation (page 87), the signals are all CMOS / TTL inputs and outputs which should be compatible with PIC I/O pins. The RX and TX lines use standard asynchronous serial data and the other signals are mostly optional with the inputs having pullups or pulldowns where necessary. The minimum connections needed are RX, TX, ground, and power.
  • mayaimayai Posts: 8
    edited 2010-01-19 13:12
    so if i just want for the bluetooth dongle to detect my eb500 does it mean i only need to active the source and ground pins?
  • Mike GreenMike Green Posts: 23,101
    edited 2010-01-19 14:40
    Yes
  • mayaimayai Posts: 8
    edited 2010-01-19 17:17
    thanks my good sir... if there's any problem i hope you can help me in the near future...
  • mayaimayai Posts: 8
    edited 2010-01-23 09:20
    its look like i've failed to connect my eb500 with bluetooth dongle.

    where did i wrong..

    CN 1 & CN 2 - grounded

    CN 20 - supplied with 12VDC

    ..........

    is there something wrong with my connection?

    and i,ve noticed that the bluetooth output is inTTL if not mistaken, so do i need MX232? or other interface?
  • Mike GreenMike Green Posts: 23,101
    edited 2010-01-23 22:45
    Your connections look correct. The EB500 signals are all TTL levels (0 to 5V). You don't need to have an interface assuming your PIC operates at 5V or has 5V logic compatible inputs and outputs. Check your power supply voltage. It should be no higher than 12V.

    Make sure the drivers for your Bluetooth "dongle" are installed properly. Follow the instructions in the EB500 documentation for establishing a connection from a PC to an EB500 (like on a BOE - Board of Education).
  • mayaimayai Posts: 8
    edited 2010-01-24 15:20
    okay finally the bluetooth is apearing at my computer.. okay the next step i connect the rx and tx of the eb500 and r and tx of pic16... but it doesnt seems to be working while i quite confident that my program is working well.. what should i do next??
  • Mike GreenMike Green Posts: 23,101
    edited 2010-01-24 16:55
    Usually RX and TX are relative to the device. You probably have to hook RX on the EB500 to TX on the PIC and TX on the EB500 to RX on the PIC. I really can't tell you more regarding the PIC. The examples in Parallax's documentation are for the Stamps. You'll have to use those to guide your programming for the PIC. If you've connected the EB500 properly and your program on the PIC actually does work, then you should have communications between the PC and the PIC. If it doesn't, then there's either something wrong with the connection or something wrong in the PIC programming which we can't help you with.

    It may be helpful to directly connect the PC and the PIC through some kind of RS232 to logic level adapter or USB Serial to logic level adapter and use a PC terminal program to display what's being produced by the PIC (and the PC keyboard to supply data to the PIC). That would help you to make sure that the PIC software behaves as expected.
  • mayaimayai Posts: 8
    edited 2010-01-25 15:26
    before i've buy the eb500 i have tried the circuit with rs232 cable.. it is working just fine... so by reffering to the eb500 pdf p5 & p6 pin is required.. in my test i did not include those connection.. it is has something to do with the problems? if it s needed i need to know what is the voltage rating for those pin.. thanks again..
  • Mike GreenMike Green Posts: 23,101
    edited 2010-01-25 15:36
    Pins 5 and 6 are optional. Pin 6 is an output (RTS) and pin 5 is a CMOS/TTL input with a pulldown resistor to set the default active state.

    Your problem is probably that you damaged the EB500 by connecting it to an RS232 cable. The EB500 inputs are designed for 0V to 5V voltage levels and RS232 uses up to 12V and uses negative voltages as well (to -12V). The negative voltages and the positive voltages above 5V can destroy the input circuitry.
  • mayaimayai Posts: 8
    edited 2010-01-31 18:03
    ok....... i,m really sure that my rs232 did not damage the eb500 because from my last experiment with rs232 cable i did it only with the cable itself... the eb500 does not have anything to do with the experiment.... it only meant to test my coding is right or wrong.... i really come to a dead end... lets take a peek at my hardware connection between eb500 and pic...

    PIN 1- ground (PIC)
    PIN 2- ground (PIC)
    PIN 20 -5V (PIC)
    PIN TX - PIN RX (PIC)
    PIN RX - IN TX (PIC)

    so... why does it still not working... please help me....
  • mayaimayai Posts: 8
    edited 2010-02-03 03:36
    hello... i just solve the problem thanks to the forum... so if there's a problem regarding PIC and eb500 please PM me...
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