Well first of all I'll start with the reason I chose to build this ground station instead of using a laptop
So after many times of carrying the laptop around assembling and disassembling parts and cables xbees usb cables and such I figured my laptop days as ground station will be numbered
Because of this I decided that I needed a ground station that would save me the need to deal with the assembling and disassembling in the field and will be more durable then my laptop
First I had to plan my shopping and inventory list
I had an old laptop with a broken screen that did not survive its frequent trips around and my poor handling skills And an older laptop screen that i planned on using with the other laptop mother board in order to do it I had to buy a lcd adapter that will let me use the vga port on the motherboard with the lvds laptop screen
That's about what I had to start with
The second thing was to look for a case that will be large enough to contain the mother board the screen another small screen that will fit in the remaining space and some lcd meters for giving a better look mostly and some 3 position switches
After many searches I found an old stock of Pelican at an affordable price and size that is suitable for my budget and needs i measured the space that left after installing the main screen and figure out that a 5 inch screen will just fit
then i needed to think of a way to install everything in a way that would give me easy access to the parts just for any case
after trying multiple materials Plexiglas plywood and others which are not very easy to work with without machinery which i didnt have access to i found just what i needed a pvc foam it is not the perfect material consider his toughness which is lacking but it is very easy to work with and so i chose it and start to cut holes and install the switches and lcds
for the finishing touch of the station i used a vinyl sticker in a 3d carbon woven pattern which gave the panel a nicer look
some technical details:
for powering the station i chose to use a sla battery instead of lipo for some reasons
first it is easier to deal with in terms of charging it and is much safer then lipo
second it is cheaper and heavier so I can save money and use it for balancing the case
i also wanted to be able to hook the station to ac power when its available
so i searched for some ac/dc converter that will meet my power demends and it turned out that i missed it in my calculation by a bit but for the moment it is working and i see no reason to change it but when it brake i'll certenly buy a bigger one capable of outputing more current
I then wanted to charge the battery while using the ac/dc convertor and giving the station more reliability i found a charger which is also a ups that is just what i wished for
also used step up regulator from 12v to 19v for powering the motherboard
and a step down regulator from 12v to 5v for powering the usb hub
both regulators are adjustable with lcd meters for convenience reasons and capable of outputting more current than consumed
bom for the station is:
laptop mother board and screen - free
pelican 1520 - ebay
LCD Controller Board DIY Kit - for connecting lvds screen to the motherboard - ebay
VGA 2AV driver board 5inch HSD050IDW1 800×480 screen - ebay
12v to 19v step up convertor with lcd for powering the motherboard - ebay
temperature meter with two sensors (inside and out of the case) - ebay
power meter with 2X lcd voltmeter and amp meter - ebay
12v to 5v step down convertor with lcd for powering usb hub - ebay
picoUPS-120 12v dc micro ups system - ebay
4X 3 position 6 pins switches - bought at a local electricity store - ebay
4X Delta Fan for Compaq 12vdc .15A 40mm EFB0412HHA - ebay
3d carbon woven pvc vinyl sticker - deal extreme
ac/dc convertor 100-240v input 12v output 3.2A or higher :) - ebay
pvc foam sheet - ebay
access point modem asus wl-330ge - ebay
usb hub 7-ports - ebay *
thermal skin for wires - ebay
I didn't really traced every buy that I made for the station but roughly everything sums for less then 400$ in total
- ebay is not the cheapest by any mean
* if you want to build your own usb hub you can do it using fe1.1s chip or similar very easily
**and so on with the other regulators it is just to my believe cheaper and faster to order it assembled :)
features of the station:
up to 2.5 hours of use on a single 12v 7Ah sla battery
secondary screen switchable between av and vga (via pc hdmi port and vga converter)
wireless connection to antenna tracker (xbee repeater, Bluetooth, 5.8Ghz)
access point modem - for multiple connection to the station (andropilot for ex)
can be easily modified and upgraded
sorry for my poor writing and description capabilities/skills
the uav station is not complete yet still need to do some more things so I will update the post as It go
Comments
@Hunter Parris couldn't explain it better thank you
Oh yeah, SLAs are WAY cheaper!
A Sealed Lead-Acid battery is a battery where the acid electrolyte has been coagulated (gelled.) Contrary to popular belief, the sealed battery is not entirely sealed. It has small vents that enable gases to release due to the electrolysis process in order to prevent bursting or expansion. Because of the coagulation, an SLA battery can, in fact, be operated upside down with no effect. A nominal voltage for charging an SLA is between 14-16v. Which means that it can be charged from a cigarette lighter, but needs to be monitored for temperature and/or voltage due to potential overcharging. A car battery charger would do just fine if you set it a a lower-voltage, slow charge. A slower charge will ensure a more equal electrolysis throughout the cells, therefore expanding your battery life.
A better option for an SLA is to do what elad essentially did, use a DC UPS system to regulate the charge and output of the battery. The PicoUPS available at mini-box.com is fairly inexpensive and very efficient at switching between battery and DC input while also charging the battery at an optimal rate. No need for separate, expensive chargers.
The regulators elad used were because he had equipment that didn't run on 12v (i.e. Laptop motherboard [19v] and USB hub [5v].) If you had nothing but 12v equipment, you can live without the regulators and power supplies. all 12v gear can run off of a 3s LiPo or a 12v SLA just fine. A Lipo has a higher energy-to-weight and energy to volume ratio than an SLA, but an SLA can supply higher surge currents, such as in a car starter, than a LiPo more safely.
The faster you drain a battery the shorter its lifespan. so an SLA with a slow current draw will essentially last years to come with proper charging and discharging techniques.
Thanks for the info! Looking at the pic the SLA is on it's side. Haven't done much with SLAs mainly liPos - is it ok for SLAs to be used on their side?
Also, can 12V SLAs really be charged straight out of a cigarette lighter? I was planning on getting a proper SLA charger...
In terms of a voltage regultor like elad mentioned - i wouldn't need one if i was running 12v gear of a 3s liPo would i?
My FPV gear will run of a 3s fine.
Cheers
What size/weight limit are you looking at for your GCS?
Lipo pros: smaller, lightweight, large power output
Lipo cons: unstable, expensive, higher maintenance (i.e. charging, handling, care, etc.)
SLA pros: cheaper, stable, fully drainable/rechargable, low maintenance
SLA cons: heavier, larger, usually lower safe power output (high power consumption devices)
A ground station would work very well off an SLA battery. LiPos for GCSs tend to be unsafe because of the possible temperature and handling of a rugged case. Plus you have to remove the battery to charge it. I'm not saying that foam and fans couldn't be added to protect it, and an easy hatch for access...but that more design and money into something you could just throw an SLA in, strap it down, hook it up and charge/discharge to your hearts content. And to top it off you don't have to lug your expensive LiPo charger to the field and monitor while its charging. You can simply plug it in to your car's cigarette lighter to charge it up.
The LCDs usually pull around 8W.
I like it elad! I am starting a ground station myself.
Does anyone know how many milliamps a basic 12v 7 inch lcd screen uses? One of those screens with RCA input. Just working out what type of battery to run a ground station off - SLA or liPo - and how many mAh for the liPo?
Thanks
almost final design
hopefully I could finish it by the end of the month and post a new complete post
things on my to do list :
program the arduino for full power control the station meters and lcd (searching for a vfd or other lcd long and narrow for installing at the top of the bottom panel to show all parameters and arduino options)
program the arduino as hid for the serial joystick to talk with the autopilots programs more easily
thinking on where to stuck the usb hub
finish to mount everything and glue the 3d carbon sticker for a nicer look
so the utile shop near my house has a shortage of the pvc foam I use for building the bottom part of the station
hence I started to work with some of the to do list I now don't have much time to work since I started my school
that to say I've added a picture of the joystick that will control the camera pan and tilt and will be installed in the station
it is a ch product hfx 2 axis with button
the other servo programed to tilt the joystick 90 degrees down or up when push button is pressed
hopefully i'll have some time and will get some pvc foam to work with this weekend so I will post more photos
http://youtu.be/w8gFWcsHZLA
Very neat set up. I'm envious!
Very nice looks great im also thinking of building one but was thinking of using a windows 7 tablet instead of a laptop just to save space and power.
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