|I Need To Come Up With Better Examples|
What's that you say? The release of the iPad 3 is imminent? Drat. Indeed it is. I need a problem to stretch this dubious metaphor even further. And that problem is the fact that Davis software products like Weatherlink and the firmware updater don't work with the DIY interface and logger. The software would scan through all the ports on my laptop and pause at the COM port assigned to the USB to Serial Adapter, but wouldn't initiate communications to it.
I thought that Davis was likely doing some kind of factory initialization on the flash chip that I was not privy to, and I wasn't going to bother disassembling the firmware image to figure out what I needed to do. Cumulus works great and is free for personal use, and the Weatherlink software has been beaten to death with the ugly stick. It burns my eyes.
|Windows 95 Called - They Want Their GUI Back|
It turns out this problem was bugging him too. He took a different approach. What if it had nothing to do with some factory initialization? What if it was a handshaking issue? So he started playing around and actually got it to work!!! Here is what you need to do, and this applies to both a straight serial or a USB to Serial interface to the console.
- Connect CTS to RTS
- Connect DSR to DTR to DCD
- Make sure to use the 1Mb dataflash chip. The console will not recognise the datalogger with larger capacity flash chips, even though it will log to it
|A Pretty Standard RS-232 Hardware Handshaking Dance|
But maybe you aren't up for this? belfryboy has got you covered once again, as he has a new version of the DIY datalogger in the works and will build you one if you'd like. He'll also be making the design files available once again for anybody to build their own. I'll put up a link to them on this blog once they are available.
I have to take my hat off to belfryboy because this solution wouldn't have occurred to me. Ever. The console does not have any lines for hardware handshaking, just TxData and RxData. Why didn't Davis just ignore hardware handshaking in their software instead of hardwiring it on to the logger board? It makes no sense, but that is the way it is.
By the way, please spare me any wailing about how this encourages piracy of the Davis software. There are many legitimate reasons for enabling this functionality in a DIY interface. Here are a few. There are others.
- Your Davis branded logger got zapped and no longer works (happened to belfryboy himself)
- You've got a Davis branded USB logger that is dropping out all of the time
- You've got multiple consoles and want a DIY version for the second one
- You've got the Davis branded logger but want to build a DIY wireless version of the interface
- You want to use the Davis updater software to update the firmware in your console
So there you have it. A DIY datalogger that has 100% of the capabilities of the Davis version, and more than two weeks before the antipated announcement of the iPad 3. That's how we roll here at Mad Scientist Labs.