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Timings for startup and programming — Parallax Forums

Timings for startup and programming

darrenodarreno Posts: 16
edited 2012-02-18 23:09 in Propeller 1
I'm new to using the propeller and have been trying to program using a cheap CP2102 based USB-TTL board I have. I've read through a few threads here an see that there are issues with using the DTR line directly from the CP2102 for reset.
I've tried with a direct connection from the DTR output to reset and also using the cap and npn circuit. I didn't see a transistor specified so I used a bc546b from my junk box.

I was wondering if there is a spec around for programming that has timings? I was thinking of using a ARM board I have to do the programming job.

Comments

  • CircuitsoftCircuitsoft Posts: 1,166
    edited 2012-02-18 16:29
    Welcome to the forums, and the propeller.

    Your BC546 should be fine. It's not a critical component. Programming is very interesting because the protocol is designed such that baud rate doesn't matter.

    Anyway, Try using RTS instead. There's a dropdown menu in the settings for the Propeller Tool that allows that.
  • darrenodarreno Posts: 16
    edited 2012-02-18 17:04
    I have tried the RTS as well with the same result. I've verifyied that DTR on the output is 3.3v when not active and 0 active. Also the terminal program echos fine when a loopback is setup.


    Is a crystal required during the bootload? I've read that the internal oscillator is used while the bootloader is running. I've tried with a 4MHz resonator on XI and also with nothing attached.
  • darrenodarreno Posts: 16
    edited 2012-02-18 23:09
    I managed to connect to the chip. I used just a capacitor without the npn transistor and it worked first time. :)
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