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serial cable reliability

Posted: Wed Sep 21, 2005 4:52 am
by ncstateboy81
I'm trying to transfer programs to a PCB over a USB/serial cable. Smaller programs around 3k transfer fine in two or three attempts (I usually just end up jostling the cable a little). But I'm trying to download a 15k one and it doesn't want to go. (Although I have in the past downloaded a larger one.)
I'm using Eric Engler's EmbeddedGNU compiler and the Technological Arts evaluation board for the hcs12c32 processor. Here are some links to the actual board and processor if it helps. ... cts_id/276<p> ... cts_id/234<p>I want to blame the cable, but I think I need to implement some transfer protocol. Although, I don't know how do that through EmbeddedGNU. Thanks for any advice.

Re: serial cable reliability

Posted: Wed Sep 21, 2005 8:40 am
by philba
there are many many possible reasons for comm errors. With a correctly implemented system, you should get no errors. What you don't say anything about is the cable. Before looking at the cable, you might check to see if flow control is needed. The IDE should have a flow control setting. <p>is it home made? if so, take a close look at it. if you touch it, do you get errors? check your grounding (a likely source of problems).<p>where are you running the cable? does it come close to noise sources (like power lines or others)?<p>What USB to serial adaptor are you using? Those are sometimes flaky.<p>what baud rate? try slowing down the transfer rate. <p>If flow control is supported, there are several options. one, RTS/CTS, requires a serial cable with those wires. I don't know if RTS/CTS works with USB to Serial connections - check the specs on your adaptor.<p>I use a boot loader with my PICs and get maybe one or 2 failed DLs out of 100. This is witha board I built so it should be of not better reliability than a "pro" board (famous last words).<p>[ September 21, 2005: Message edited by: philba ]</p>