Trying to find USB interface
I'm working on a project and have moved all my components to my own PCB board including the BS2. I want to be able to directly program the BS2 while it is on my own board and not have to move it over to the Discovery Board to program it. Another reason I want to have a USB interface on my own board is so I can read all the outputs on my desktop while the chip is running. I was looking at USB2SER Development Tool Item code 28024, but it says in the description that I cant use this to program the BS2 since
"Programming a BASIC Stamp from a USB Port
The USB2SER is not able to program BASIC Stamps. BASIC Stamp modules require an inverted signal. If
you need to program a BASIC Stamp, use the Parallax USB to Serial (RS-232) Adapter (#28030)."
What I'm getting from this is that I need to get the RS-232 adapter instead and wire it up as shown below.
Image Attachment :
"Programming a BASIC Stamp from a USB Port
The USB2SER is not able to program BASIC Stamps. BASIC Stamp modules require an inverted signal. If
you need to program a BASIC Stamp, use the Parallax USB to Serial (RS-232) Adapter (#28030)."
What I'm getting from this is that I need to get the RS-232 adapter instead and wire it up as shown below.
Comments
-Thanks
www.parallax.com/Portals/0/Downloads/docs/prod/boards/BOE_USB_D_Schematic.pdf
This IS in fact the way the USB interface on the Discovery board works, except the USB to 4-pin interface is replaced by an FTDI USB chip and wire on the board. I suppose you could pay the extra bucks to have the FTDI USB interface chips on your own board -- but really, 4-pins and a reuseable adapter is WAY cheaper (and easier to get right) than a USB interface installed on every one of your target boards.
Thank you Ill give it a try
Then all you need IS a $20 or less USB to RS-232 adapter module -- it's gonna cost WAY more than that to re-invent the wheel.
And the USB2SER adapter STILL isn't going to work -- the BS2 requires RS-232 signalling levels, +- 3 volts. The USB2SER is TTL only, as I understand it.
That is correct, the USB2SER is used for communication only not for reprogramming. The USB to Serial adapter (#28030)·is the far easier way of converting serial to USB; however if you want build the USB circuit, than Mike's suggestion to use the BOE schematic is going to be the best example to follow.
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Respectfully,
Joshua Donelson
www.parallax.com