In my implementation, I have TWO AC4790-1000Ms deployed.
The first one is on the Aerocomm eval board that's hooked up to my laptop via USB. Where I have my C# app that Tx/Rx data to this AC4790. I call this the "Command Center"
The second one is hooked up to the Arduino Mega and the code running in Mega handles the Tx/Rx to this AC4790. I call this the "Rover Comm Module"
The traffic btwn the 2 works like a charm.
The issue I am facing is the range btwn the 2. The manufacturer's data sheet explains that under line of sight, w/ a 3dbi antenna, one could get 20mile range. While I am not shooting for 20mile range, I am however shooting for at least a mile. But, all I am getting is 4 feet. If I go any further than 5 feet, the command center is able to Tx and the Rovr Comm Module receives and is taking the action. However The data transmitted by the Rover Comm Mod is not received by the Command Center module.
On the Mega side of things, wrt power supply to the AC4790, I have connected pin 10 to the Mega's 3.3v. From talking w/ the Aerocomm's tech support guy, he explained that pin 10 can take 3.3 to 5v. But, if pin 10 is connected to 5v, the pin 11 must be 3.3 V. In my case, pin 10 is connected to 3.3v therefore pin 11 can be left disconnected.
can someone in this forum w/ AC4790 experience shed some thoughts on how much range you are seeing and how you have accomplished longer range Tx/Rx. I dont want to add a long antenna because, my Rover is really an Etrax C truck and i have limited realestate vertically and horizontally.
I have not use the AC4790 myself, but base on the User manual on page7, you need to supply Pin 10 with 3.3V 1.5A of current. The Mega 3.3V can only supply max 50mA. That will affect your range, since Tx 100% need about 1.3A from supply.
another question on what antenna are you using with AC4790?
thank you for taking a look at this. I completely missed checking the power needs for Tx. I think i should branch off to a separate 3.3v regulated that can supply 1.5A power source. Can you recommend a 3.3v regulator that can fit these needs. I know LM317 adjustable voltage regulator can be set up to take care of this. But, if there's a better option that people have used here, that would be good to take a look at.
bump : wanted to see if any one had any recommendations on below please. thank you
Can you recommend a 3.3v regulator that can fit these needs. I know LM317 adjustable voltage regulator can be set up to take care of this. But, if there's a better option that people have used here, that would be good to take a look at.
LM317 5v or 3.3v out kit. You can go pick up a junk wall wart that puts out a couple amps at a thrift store for 99cents or so. Should be able to feed 9-20vdc in and get either 5 or 3.3 out
It maxes out at 1.5A so you could replace the LM317 with the other mentioned device. Both should have a heat sink but that can be made with tin snips and a soup can.
i think this should keep me going w/ the range. I had also pinged the Aerocomm technicians asking abt the range question I had. Here's the verbatim I sent...
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Hi Chris, et al;
I am trying to supply the AC4790 1000 T/Rx module w/ a regulated 3.3v 7amp Max. I have a couple of ?s
The main reason why I am providing a dedicated regulated supply of 3.3v 7amp max is because I would like to get the max range as possible from this module. I have the AC4790 SDK kit's antenna. The module is installed on my “land roving autonomous robot”. For me to get a max T/Rx from this module to the Homebase station (Homebase station has the dev kit connected to my laptop's USB), is this a good enough set up. I am looking at at a min getting a 5 mile radius w/o a clear line of sight (neighborhood houses, trees, etc).
Wrt grounding?
a. I am planning on connecting the 3.3v Vin to the T/Rx module, while the ground to be connected to my microcontroller's ground. What is the recommended path to ensure this does not blow up on me,
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if any of you have any recommendations, please let me know and is much appreciated.
