Wednesday, May 11, 2016

New Mapping Setup and Lowrance Elite 7 Ti Review

After the first of the year I had a $1000 in my "Boat Improvement Fund" and knowing the HDS Gen 3 units were out and Lowrance was getting ready to end new production on the Gen 2 Touch I decided to see if I could find a setup for under a grand. While searching for deals on the Internet I stumbled across the just released Elite 7 Ti which was not only cheaper than the Gen 2 Touch it uses a single transducer for CHIRP, downscan and sidescan. Having a 16ft by 48" modified jon boat it was problematic get 2 transducers on the right side in 'clean' water and spaced at least 12" apart which is part of the reason I hadn't invested in a side scan unit.

For all practical purposes an Elite 7 Ti is a HDS Gen 2 Touch 7 without the ethernet outputs but does have the built in Go Free WiFi allowing it to be viewed on an Android or Apple smartphone and viewed and controlled with an Android or Apple Tablet (Unfortunately nothing for Windows Tablets but I have a workaround for that later) It uses the same SoC (System on a Chip) as the Gen 2, a NXP i.MX6DL which has a dual core ARM Cortex A9 microprocessor and fairly powerful GPU core with dual display outputs (one for the LCD touchscreen and one for the WiFi output streaming to phone or tablet) and hardware video decoding, a 20 bit parallel camera interface, USB interfaces, UARTS (NMEA 0183), 2 CAN bus transceivers (NMEA 2000) and a gigabit LAN core (Although there are no ethernet outputs the WiFi still needs and uses this core) I wasn't able to determine the speed but it's either 800 MHz or 1 Ghz. Basically the same basic setup as the HDS Gen 2 Touch. It also has a WiFi/Bluetooth combo radio but currently the Bluetooth hasn't been enabled and there is no interface/screen for it until they update the firmware (They were saying early 2016 but I notice that disappeared a couple of weeks ago) It also has RS422/485 level NMEA 0183 Input/output and a NMEA 2000 protocol port. Frankly as an EE who worked for an industrial process control manufacturer in the late 90's  I find the pricing on NMEA 2000 networking gear to be ridiculously expensive for a modified CAN bus that was developed over 30 years ago. 30 bucks just for a 2ft cord with 5 freaking wires in it that probably didn't cost even 2 bucks to manufacture in large quantities (> 100,000)  Can I afford it? Yes .... Will I pay that much, no freaking way. At best I'll buy a couple of the cords for the finders if I can find them cheap enough and build my own backbone

All in all it's a pretty responsive unit (granted I've only tested it it "on the bench" and haven't had it out on the water yet) and I've been able to make some decent maps for it since it allows control of 2-3 layers. For instance I can easily convert existing photo maps by 'tiling' them in Garmin KML/KMZ format and running them through Insight Map Creator which I can use as a shaded relief background which I can do live sidescans over or I can use it in the foreground and adjust the transparency for the isolines and depth labels to show through a vector depth map. Now I'll be able to log more than just depth and position but also hardness, downscan and sidescan data. Then I can play back and see exactly what I saw (or missed) while I was out on the water and then mark waypoints in the comfort of my own home on my main PC (Or play logs back in the finder itself)

However there are a couple of minor drawbacks that I had to make work arounds for. First is a problem every combo Finder/Plotter has. You have an error due to the transducer and the GPS antenna being so far apart, in my case about 8 feet. So if I am going from east to west and object on the finder is going to be marked 8 feet west where the GPS antenna is located. Now if I turn around and go from west to east the same object is going to log 8 feet to the east which is a total error of 16 feet. Now that may be OK for general use but for making maps it's just unacceptable. My depth mapping software can compensate for the error in software but it's a real nightmare to get and keep calibrated. So the solution I came up with back in 2010 was first using a USB GPS puck and an extender cable to place it over the transducer on the back deck which proved to work well as far as calibration and accuracy but the USB could be flaky and would often glitch when I started the motor. so in 2012 I went over to amplified antenna that are in some of the photos I posted last summer. So I basically reworked the multiplexer/logger/GPS unit I made last year and am sending just the GPS to the NMEA 0183 inputs on the Elite 7 Ti which automatically picked it up and switches back to the internal GPS if I turn it off. (Nice job on that piece of programming by Lowrance) I'll detail that unit in the next post (It also outputs NMEA position data to the USB port and a Bluetooth radio)

Then the other minor drawback although likely not a big deal for the vast majority of people is they didn't bridge the NMEA 0183 data to the ethernet and then stream it out a UDP port like on the HDS Gen 2 Touch even though the WiFI still uses the ethernet LAN core built into the i.MX6DL SoC. Basically all it would take is a few lines of code for Embedded Linux to bridge it to the LAN core but I guess since they dropped the ethernet outputs they wrongly thought it wasn't still an option. I've been messing around with a little WiFi module based on the ESP8266 WiFi chip and when I went looking for a way to use it by transmitting the NMEA 0183 output of the Elite Ti I found that someone had already beat me too it so I slightly modified it and it sends NMEA depth and position data to my main Windows Tablet PC which is set up as an Access Point/Hotspot which other devices can connect to (Like my Nexus 7 tablet running Open CPN) I'll also go into more detail on that device (I have under $10 in it) in my next post in a day or two. I'll also detail an undocumented web browser interface I found when trying to port scan the Elite Ti looking for the NMEA over WiFi. that allows some files to be transferred to any device that has a web browser and WiFi

1 comment:

Aleksandrs Bebrišs said...

Amazing!!! When You will be ready with You project I will buy one unit :) if You will be ready to sell it. I will use it with my bait boat ( for carp fishing ) This boat will be also like autonomous mapping robot. Hull will made from PVC pipes what guys from France use often can see in this video Tanks sharing this project. I am Your follower.