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[WP-34S] Cable and flashing options for Mac users
01-19-2015, 06:50 PM
Post: #22
RE: [WP-34S] Cable and flashing options for Mac users
Thanks for the replies, much appreciated. I am traveling for a few days and will report what I find later.

(01-18-2015 09:56 PM)Marcus von Cube Wrote:  It therefore sends some trigger bytes at what it assumes to be 115kbit/s. It then gets back an answer (or not) and retries with a slightly modified oscillator setting. Maybe the Prolific chips just discard the sync data if the baud rate is off too far. So the Atmel boot loader never knows how to adjust the frequency because it never sees any response from the PC or Mac.

Interesting. What a mess! I was curious what baud rate was used, especially in a device lacking a reference oscillator. In one of my attempts I tried sending the binary file using Markus Schmid's ZOC at 9600 baud. It repeatedly stalls at about 31% after which his program froze, leaving the open port in an unknown state. It's an otherwise excellent program, but things like this leave me skeptical.

I'll try again at 115 kbps but if MySamba (and wp34sflash) are required to provide intelligent responses to queries from the WP34s then I obviously can't simply use a terminal emulator to flash the unit.

Which leads me to:

(01-18-2015 10:42 PM)jebem Wrote:  you could test your PC to USB-serial-cable link, by connecting the TxD and RxD wires with one 1K resistor to from a loopback.
On your tty test program, you should receive every single character that you type on the keyboard.

Yes, I did that, and the initial results using ZOC led me to believe the loopback was not working. I was going to measure the serial signal with an oscilloscope but I had little time for further testing. I'll do that, and try other TTY - emulator software when I return. It would be nice to confirm actual data transmission, or at least the attempt to send data.

(01-19-2015 05:50 AM)pascal_meheut Wrote:  ... I wrote the wp34sflash program and it should work the same being rewritten from the MySamba source code and sending the exact same bytes.
Flashing is incredibly sensitive to the driver and other parameters and I have never been able to make our "portable" flash program work as well as MySamba (and never and the time nor the inclination to do so).

Thank you for writing that program! Do you know of any USB to serial devices that would work for my application? The cable I bought might be unsuitable, perhaps even inoperative, but it only cost $2 to find out.
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RE: [WP-34S] Cable and flashing options for Mac users - John Galt - 01-19-2015 06:50 PM

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