Shop OBEX P1 Docs P2 Docs Learn Events
FT232 Propeller Reset Communication Issue — Parallax Forums

FT232 Propeller Reset Communication Issue

slcottslcott Posts: 27
edited 2010-04-21 02:44 in Propeller 1
I am having trouble establishing any communication with my propeller chip through my FT232RL chip. I think all the connections are correct on the FTDI usb to serial converter but the connections between converter and propeller are the problem. I have set BOEn to Vss so that RESn has a weak 5K pullup to Vdd as specified in the documentation. I have tried to follow the guidelines of the demo board schematic in order to toggle the RESn line correctly but have run into trouble. After spicing my schematic (based off the demo board schematic) it looks like RESn won't be properly toggled. I replaced the 15K with a 100K as my spice model indicated.

If someone could point me in the right direction here as to what I need to do, I'd appreciate the help.
demo_board.png
315 x 472 - 18K
my_schematic.png
883 x 680 - 45K
spice.png
1400 x 1022 - 73K

Comments

  • slcottslcott Posts: 27
    edited 2010-04-20 14:23
    So as it turns out, integrating the prop plug into a board is a bit of work. I think the problems I was dealing with may have been related to the needed an external power supply and not simply power from the usb bus.
  • mynet43mynet43 Posts: 644
    edited 2010-04-21 02:44
    I have a board using the FT232RL that works fine using power from the USB bus. It even works on a USB hub, which has less power. I take the 5V from the USB and run it into a 3.3V regulator to power the Prop etc.

    The usual problem with resetting, when using the USB chip is that the LED's on the FT232 chip cause it to have a little power when it's not connected. This causes problems with the prop reset circuit. If you're getting power from the USB, you shouldn't have this problem.

    Let me know if you need more info, or a copy of my schematic.

    Jim
Sign In or Register to comment.