Lynxmotion Tech Support

I'm in the process of ordering the Spektrum DX6i radios for our website. I'm relatively new to these radios, so I'm open to comments on what accessories I should carry.

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Jim Frye, the Robot Guy
http://www.lynxmotion.com
I've always tried to do my best...

Which model receiver comes with it?

I'm working on getting them with the Bot Receiver.

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Jim Frye, the Robot Guy
http://www.lynxmotion.com
I've always tried to do my best...

definetly one of these:



I didn't see any information on the robot reciever. I like the LCD display on the front, but I wonder if you can change the airplane graphic with something else? if not its no big deal. The transmitter looks awesome.

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Mike

The robotics nut.

This is the Bot Receiver.



Spektrum’s BR6000 receiver is designed for robot and special application usage where it’s desirable to have the failsafe drive all channels to a preprogrammed position during loss of signal vs. hold the last command.

BR6000 DSM DuaLink 6-Channel Bot Receiver

Key Features
o Unique programming specifically for bot applications
o Failsafe allows you to preprogram positions to shut down systems in case of signal loss
o Patented DuaLink incorporates two receivers in one
o Ultralight 7 grams
o Compact design 39 x 39 x 9mm
Overview
Spektrum is happy to announce a specially-programmed receiver specifically for robots and battle bots. This is ideal for applications where it’s necessary to shut down systems (ie. weaponry, drive motors, etc,) during loss of signal to prevent an unsafe condition.

If you currently own a DX6 radio and are using it in a robot application, you’ll want the new BR6000 receiver.

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Jim Frye, the Robot Guy
http://www.lynxmotion.com
I've always tried to do my best...

Hi Jim,

Now you decide to sell Spektrum products!

I just bought a DX6i and BR6000 receiver from Robot Market Place.

You might want to check Robot Market Place's pricing as it was very competitive and they allow you to specify what receiver you want with the DX6i.

My transmitter/receiver only came with a battery charger for the NMHi transmitter batteries (4.8v) and I had to buy a Spektrum receiver battery/switch harness separately.

The DX6i is a nice tranmitter and will work with the Endurance R/C PCTx through the trainer port.

I plan to use the DX6i with one of my bigger rovers.

Regards,
TCIII

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If you are going to send a Robot to save the world, you better make sure it likes it the way it is!

Hi,

This is great news!
I also considered the Spectrum transmitter for a while... But I'm very curious how your gonna add/modify it for supporting more switches/functions
Did you get some inside information from Spectrum how to solve that?

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[b]Kåre Halvorsen, Zenta[/b]
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Zenta's blog
http://zentasrobots.com/
Zenta's YouTube channel
http://www.youtube.com/ZentaOlbaid
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Hi Jim,

Adding the DX6i to the product line is a good thing! It sounds like you’ve got some good connections with spectrum so maybe you’ve got a answer for the following questions.

Since Zenta posted a spectacular video of his remote I’ve been looking for a receiver with a single output like RS232. This would spare a lot of I/O pins. I found a receiver at futaba which has a separate RS232 output. I didn’t found out how you could use it but if there is a receiver with just one RS232 output instead of 6 or more PWM signals it would be a great solution for robotics!

I also thought about adding more functions (read buttons) to the remote and I was wondering. As far as I know (and that isn’t a lot if it comes to RC) there are a few switches connected directly to one channel. I think that the switch alters the PWM signal of that channel but is it also possible to let the switch toggle the signal between 0 and 1? If I think of the practical way it should because maybe you want to be able to turn on/off some lights of your remote plain/boat/heli…

If it does, it is also possible to add your own PWM signal on that channel which means that with some simple electronics it is possible to send a lot of data

Could this be possible or have I got it all wrong?

Xan

Hi Xan,

The receiver you refer to is a 3ch only
But it would be a great solution to save time. I've been thinking of using an extra BAP or Basic Stamp or maybe just a simple PIC to take care of the pwm inputs. So far just thinking...


Often you can assign one switch to one channel. If you assigned a 2 state switch to one channel, the pwm output would be ex 1050 and 1850 for each state/position of the switch. What I didn't find out on my dad's Spectrum DX7 (he didn't allow me to experiment too much.. ) was if the switches on the transmitter was connected to a internal A/D converter or just a logic input (1/0).

Jim; do you know something about that?


What I think might be possible is to use a 8 bit D/A converter connected to the RC transmitters ADC. Would be fun to try it one time!

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[b]Kåre Halvorsen, Zenta[/b]
-----------------------------------------
Zenta's blog
http://zentasrobots.com/
Zenta's YouTube channel
http://www.youtube.com/ZentaOlbaid
-----------------------------------------

Ok, the radio is digital so I suspect there will be an easy way to inject a custom pulse into the stream that goes from the main board to the transmitter. I haven't received any schematics yet. The actual transmitter module has a three pin connector. power, ground, and signal. I'm not completely sure what the "signal" is yet. But I remain confident that a dedicated pic should easily be able to replace the 5th or 6th channel data with a 16 level analog output that matches which key is pressed on the proposed keypad. Utilizing both channels could result in up to 256 different key combinations.

I found this with a google search.





I have the DX6 opened in front of me. They have incorporated 3 switches into each of the two additional channels. I'm going to have to dig deeper to trace things out to see if the two additional channels are indeed analog on the main board.

This radio appears to be highly modifiable!

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Jim Frye, the Robot Guy
http://www.lynxmotion.com
I've always tried to do my best...

Eureka !!! This is going to be SO easy!

The signals from the main board to the transmitter are 5vdc pulse lengths !

The pulse train is made up of pulse lengths in between 0.39mS positive going pulses. The low pulse length is proportional to the servos position. It varies from 361uS to 743uS per channel. Using a fluke 123 scopemeter. Can't figure how to measure the off time, but it looks like 13mS. Hrm, it looks like the data exchange is sub uS resolution. or there is only 382 steps for position control...




Edit: I had to update the pulse length values.

_________________
Jim Frye, the Robot Guy
http://www.lynxmotion.com
I've always tried to do my best...

Nice work Jim,
Keep us updated! This thread really starts to get very interesting..

_________________
[b]Kåre Halvorsen, Zenta[/b]
-----------------------------------------
Zenta's blog
http://zentasrobots.com/
Zenta's YouTube channel
http://www.youtube.com/ZentaOlbaid
-----------------------------------------

Hi,

LOL



Yeah! If it is possible to add your own signal on channel 5 and/or 6 it is getting very interesting! A 5V pulse signal should be easy to adapt with a additional pic or something. If you could arrange a schematic of the remote it should be possible to build your own custom robotic remote!!

I’m looking forward so see more information on this!

Xan

I've given this a lot of thought overnight. This is going to be a very popular controller.

The next step as far as I'm concerned is to write an Atom Pro program to do exactly what I want to do with a custom pic or atmel chip. It's fast enough. My plan is to have a 4 x 4 matrix on channel 5 and a 2 x 4 matrix on channel 6. The 16 keys on channel 5 are the main keys for turning on and off outputs and or changing the behavior of the bot. The 8 keys on channel 6 would be "shift" keys to provide 64 unique key presses. Technically if 16 keys were used on both channels 256 unique key presses could be realized, but I think it's would be overkill.

At the same time we need to start finding the appropriate components for the keypad. I think real key switches would be better than the membrane ones, but I'm open to suggestions. Going to need to find a cheap enclosure for the keypad too.

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Jim Frye, the Robot Guy
http://www.lynxmotion.com
I've always tried to do my best...

Hi all, I've had a bit of experience with this kind of stuff.
The pulse train you have shown above is very common for RC transmitters, and can often be read from the buddy/training port of the Tx. My understanding of the off time you have referred to is that it is not crucial, but must be long enough not to be mistaken for a channel's signal (keeps the sequence right, and is therefore compatible for a range of channel amounts).

I would expect the switches to be digital inputs to the main board. A way to check this is to see if there are any resistors on the switch, or on the board near the switch, as these are required to give the analogue voltage. I find it unlikely though as digital inputs are cheaper and easier to work with.

These radios are quite customizable in relation to what switch does what, and what stick axis etc. I have a dx7 and there are many options. Eg:
switches can be set to any specified channel, stick axis can control multiple channels, exponential etc.

I have always thought a handy module would be to program a pic or something to receive the channels of an RC Rx and output a single signal (such as RS232, or a similar signal to the internal one of the Tx with a pulse for each channel). I have yet to program this, but it wouldn't be hard to achieve.

I'm glad you opted for the DX6i, as there is more flexibility with DSM2.
I would recommend supplying the AR6200(two separated receivers) for those who want a bit better range with less chance of glitches.

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Steve