Stan and beowulff, great posts, thanks.
I did find a USB 1.1 hub in the basement, which has a plug in 7.5 V power supply. I added it to the setup and now it works.
That is, my setup contains
- Desktop PC with 1.1 USB ports
- One end of the USB to Cat5 adapter kit
- 50’ Geek Squad premade Cat6 cable (I assume 6 means somewhat better bandwidth, dropin compatible with 5e)
- Other end of the USB to Cat5 adapter kit
- USB cable, one end flat to fit USB ports on a PC, the other end square with 2 flatted corners, like it would fit the USB port on a printer
- USB 1.1 hub with #5 plugged into its source port and its wall wart on an extension cord plugged into 120 VAC
- GPS receiver’s dedicated USB cord plugged into one of the general purpose ports on the hub
- GPS receiver puck (the connection between the puck and its cord doesn’t look familiar to me, maybe it’s the mini 5 wire USB you mentioned? I’m logging data now and don’t want to break it to look)
I think the fact that this works is consistent with the idea that there was too much voltage drop in the line to power the puck, but doesn’t prove that idea. For example, I guess there could be a timing problem, and the hub is in some way more robust than the puck in this regard, so it doesn’t have the same timing problem. Anybody want to weigh in on this? The right way to answer it is to cut open a USB cable and measure the voltage there as beowulff suggests.
I guess this is obvious, but AFAIK the use of the Cat5e/6 cable is proprietary inside the adapter kit and we can’t actually assume anything about what is going on in that cable. I mean, it wouldn’t be Ethernet traffic.
I think I will want to create a more permanent installation with a longer-than-50 cable I will make up. So, I think I do need to check the voltage, before I go fishing cables that won’t work.
Stan Doubt, I think this puck is communicating proprietary data to the program that talks to it. It’s GPS data, but it’s not NMEA. The GPS data includes pseudoranges and carrier phase data and Doppler shift data, as well as Almanac data, all of which aren’t part of NMEA informatio (well, the 183 version that I know about, anyway). The products are an EarthMate receiver and GPS PostPro 2.0 software from DeLorme. They say they are transferring and logging “RAW” data into a “.raw” file format which isn’t useable by other company’s products. I just interpret this to mean it’s their proprietary format, undocumented to the end user and reserving the right to mess with future version changes.
I don’t know enough about USB to even know if it has baud, handshaking, parity, and other features analogous to RS232. Certainly, not anything they describe in the product docs.
RINEX files are text files that have been formatted in certain ways. The receiver probably isn’t sending anything that goes directly into the RINEX file without being processed in some way first. The software, while it is logging, also displays the “raw” data, and it is displayed as an unbroken stream of numerals and A-F letter characters, no spaces, wrapping to fit the window. I presume these are hex digits but they don’t say. There are many sequential zeros in big chunks of the data, especially when I first turn it on.