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Old Aug 09, 2007, 11:38 PM
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Quote:
Originally Posted by ccdengr
Would it be possible to rerun your channel survey with the CCPM switch set?
BTW, what I'd hope/expect is that moving the left stick up would increase channel 1 (throttle) up to mid-stick, and then increase channels 1, 2, 3, and 6 thereafter, and that moving the right stick left-right and up-down would change channels 2, 3, and 6 in some combination (120 degree CCPM mixing).
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Old Aug 10, 2007, 04:35 AM
VE7FM
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Wouldn't it be easier to plug servos into the receiver instead of looking at serial data?
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Old Aug 10, 2007, 08:55 AM
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Quote:
Originally Posted by TheSteve
Wouldn't it be easier to plug servos into the receiver instead of looking at serial data?
Sure, if I had a receiver like an AR6100, but all I have at the moment is a CX2 4-in-1, where I don't think I can get at the throttle channel in PPM form. Didn't want to buy one without proof-of-concept. It just sounded like you had a simple setup to look at the serial data, but I could imagine your previous characterization took more work than you'd want to duplicate. Thanks anyway, I really appreciate your efforts!
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Old Aug 10, 2007, 11:26 PM
VE7FM
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Was looking at the serial output for some other testing tonight so I tried the various dip switches. From what I can see there is no mixing implemented in software.
In the default setup channel 6 tracks the left stick with less travel. In any other setting channel 6 doesn't follow the left stick at all, no other channels do either.
DIP 9 is channel 5 reverse
DIP 10 is channel 6 reverse
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Old Aug 29, 2007, 12:03 AM
VE7FM
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I finally got around to building the hardware needed to convert the PPM data to the serial stream for the DSM2 module. Here are a few pictures of the new TX module. The hardware is outputting serial data from the PPM stream using code written for an Xbee at the moment. As you can see the pcb is a one off using perfboard and through-hole components. The CPU is an Atmel Tiny2313 clocked at 4Mhz. There is the standard programming header (10 pin) as well as a set of 8 sockets which are accessible through the original crystal hole. These were added for compatibility with my original Xbee Pro tx module. Using the 8 pins I can reprogram the Atmel as well as program and flash an Xbee without opening the case. The pcb was designed such that an Xbee Pro or the Spektrum DSM2 module from the LP5DSM will fit just fine. The power supply is currently only good enough for the low power DSM2 module but will be upgraded after Digikey delivers parts tomorrow. There is also a transistor driver to pull the RF sense pin low which will enable the LED on the front of the 9CAP. If used with the Spektrum DSM2 module this will be connected where the LP5DSM LED is normally connected, if connected to an Xbee Pro I would drive this with an output from the Atmel. Both plastic cases and the 5 pin socket connector were robbed from existing Futaba tx modules. My original Xbee Pro module has the antenna connector on the back(along with a bind button and two LEDS) as its used with a pistol grip surface radio. The new module has a small plastic project box attached to it which allows the antenna to mount on the top. Even though its close to the module release clip there are no problems getting the module out and a 2.4Ghz half wave dipole fits perfectly with a good angle. The final DSM2 compatible serial software should be done in a few days so I can give it a proper test and fully install the DSM2 pcb.
I'll take more pictures and post an update when thats done!
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Old Aug 29, 2007, 08:41 AM
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Did you find a way to stop the "no rf" beep for the 9C? I'd like to connect my Plantraco Monolith LED the same way, but it flashes during use, and I don't want the constant beep.

That's a pretty clever use of the hole for the crystal, I don't think I would have thought of that.
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Old Aug 29, 2007, 11:44 AM
VE7FM
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I wasn't too worried about the no RF alert as the LED from the LP5DSM only flashes for a few seconds at power on while its in binding mode. It will cause the no RF alert to go off for a few seconds but then it will stop. You're better off not powering on the receiver while the transmitter is in binding mode so I figure the alert will tell me when I'm good to power on the receiver.
Using the crystal hole has an even larger advantage on my Futaba 3PJsuper pistol grip radio as it was designed to allow the end user to swap the crystal without removing the module. This has enabled me to monitor serial/debug data while the radio is running by plugging a cable in.
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Old Aug 30, 2007, 04:20 PM
Formerly P4 Hover
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Quote:
Originally Posted by village_idiot
I've been going over ebay for those, and people keep selling them for very close to what Servo City sells the Hitec modules for, so I think I may just go ahead and buy a new Hitec for my Plantraco stuff. Wish I hadn't passed up the Servo City $10 sale a few months back , I wasn't thinking about prototype materials at that time

What do you search for? All my keywords resulted in nothing.

Its great to see someone else came up with the same idea of using the X1OEMTX board (TX board in LP5DSM) to make their own DSM2 TX.

Steve, how close are you to releasing the software? Do you need beta testers? I want to build a module so I can fly my CX2 with my Optic 6.

-Jon
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Old Aug 30, 2007, 06:17 PM
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I always just search for "futaba module", but it looks like there isn't much available right now.
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Old Sep 04, 2007, 05:22 PM
VE7FM
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Quote:
Originally Posted by Zeta Phoenix
Steve, how close are you to releasing the software? Do you need beta testers? I want to build a module so I can fly my CX2 with my Optic 6.

-Jon
I will hopefully be flying a Heli with it this evening.
I will have to do some testing and fine tuning before any release.
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Old Sep 05, 2007, 12:46 AM
VE7FM
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It works!!!

I hovered my blade CX2 in the kitchen for 2 minutes or so.(yes yes hovering a blade CX2 is nearly trivial but its a *really* small kitchen and the wife was watching to make sure her kitchen was unharmed)

I had to add a second transistor to invert the LED output from the 2.4Ghz module. The "RF Good" indicator on the 9CAP works perfectly now. When you power it on it blinks(bind mode) just like the original LP5DSM did and then goes solid on when it exits bind mode. The 9CAP NO RF alarm goes off twice during this time because its input is blinking which is perfect, the alarm goes off just as bind mode is finished.
We also have two LED outputs on the Atmel itself, one is a power on self test LED so you know the Atmel is running, the second indicates its receiving PPM data. I didn't bother adding external LEDs for these, using the RF good LED in the 9CAP already verifies everything is working.

The Atmel tiny2313 is clocked at 4Mhz which gives 250ns or 4096 step resolution(same as XPS!, 1/4 the clock though, gotta love Atmel) The data is then shifted two bits(or divided by 4) to give 1us resolution(1024 steps) which is what the LP5DSM module requires. We then reorder the channels so they match what the LP5DSM uses(not like its easy to just unplug everything in the Blade CX2 4in1 unit to change the channel order) Finally its all directed out the UART at 125K. We are currently dumping PPM channels 7 and 8 but who knows, they might work. I'd need a 7 or 8 channel Spektrum receiver to try it. The code change would be very simple. We have limits in place so the proper 1024 bit values cannot be exceeded. The only possible way to generate an error right now we can think of would be to plug the module into a radio providing fewer then 6 PPM channels. We could add error checking for that as well if needed.
As the code is it should work in any Futaba module radio, and any other radio with the same channel layout and polarity PPM data.
I will do a more extensive range test and fly a few battery packs outdoors tomorrow.
So far though I am very pleased!

Next project is to build a third module with an xbee pro in it for the 9CAP to use with our 8 channel xbee receiver. My current xbee pro module is hardcoded to work with my 3PJs 3 channel surface radio and the antenna location isn't optimized for the 9CAP.
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Old Sep 05, 2007, 09:20 AM
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Great work! I have been following this thread and the Open Source 2.4Ghz transmitter thread. I'm really looking forward to schematics and code so I can start another project. This or the xbee module would be a perfect match for my planned Microstar radio conversion.
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Old Sep 05, 2007, 11:55 AM
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If you felt like tinkering with the Microstar code, I see no reason why you couldn't send the data directly to the RF section instead of converting it to PPM and then decoding the PPM to serial.
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Old Sep 05, 2007, 12:18 PM
VE7FM
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I haven't looked at the Microstar but assuming it has a free UART you could directly drive the DSM2 module or an xbee.
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Old Sep 05, 2007, 06:28 PM
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It's a PIC 18F chip, and it definitely has a spare UART, could probably just use the IO pin that it now uses for the PPM to send the serial data, I think most of the io pins are mapable to the desired function.
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