I really miss the timer function that I’m use to having on my Futaba 9cap. Having moved over to a DX7, I find the timer function pretty much useless. I don’t like the fact that I have to press the start button to start the timer and again to stop it. I much rather have the throttle turn it on and off. I don’t know why Spectrum didn’t incorporate this into the software. Having to time my flights is important, especially since I’ve move over to A123 cells. They only give you one shot at landing once the cells dump.

I ended up making a board and programming a pic to do the button presses for me. There are only 4 connections needed. Two are power and +5volts. The other two is a wire to the timer button, and one to the center tap of the throttle pot.

If there is interest I can run a batch of these, a complete board would be $20. Here are photos of the mod. If it's not a year old then this will probably void your warranty.

Kin

http://www.embeddedtronics.com/

Where are the photos?

Photos now posted.

Originally Posted by madhun1

Where are the photos?

Kin - Count me in for two at $20 each. I'll just need to find the 5 volt tap on my 9303. Mine will be a year old soon.
Please let me know where and how to pay.
I'll print this thread and show the guys at the club field.
You can expect a few orders from the other ex-Futaba here in Eastern Carolina.

Hi Kevin,

I finalized the software last night, you can send payment to my paypal address. kinf@embeddedtronics.com

I made a small intial batch, the board is what is posted. Once these sell off. I will start a new batch. The new boards will be smaller, but functionally the same. The software is setup for the DX7. I'm not sure if it can work with the 9303. The switch would need to be the type that gets grounded when pushed and the system should be a 5volt setup. I measured the throttle voltage at the center tap of the pot when it's all the way down on the DX7 and found it to be 1.1volts. If your's is at a different voltage, I would have to change the software for you, something that would be easy for me to do.

Kin
http://www.embeddedtronics.com/

Originally Posted by Kevin Murray

Kin - Count me in for two at $20 each. I'll just need to find the 5 volt tap on my 9303. Mine will be a year old soon.
Please let me know where and how to pay.
I'll print this thread and show the guys at the club field.
You can expect a few orders from the other ex-Futaba here in Eastern Carolina.

So exactly how will it work? Is the throttle stick activation point adjustable? I think a lot of people would be interested in a 9303 version for sure. Would need to know where to easily find the power and ground points.

I'll only PayPal for one, try one first.
The switch and potentiometer should be the same standart for Jr/Spektrum but the 9303 being more feature packed I need to see it that boadr will physicaly fit into the transmitter case ... so I'll only get one.

PayPal sent.
km

When the throttle moves from it's lowest position, it sets the timer to start. I kept it simple for now. I have no need for any point adjustment. In order to do that I would have to put an external switch. It would be pressed when throttle is in the set position. Is there a need for this?

Ground is usually easy to find since it is the negative terminal of your battery.
On the Spectrum, they have the throttle connected to power and ground, so I used those 2 connection. The switch was easy to find, it should be at 5 volts and goes to zero once pressed. The center connection of the throttle would be the forth connection to make. Only 4 connections are needed.

Kin

Originally Posted by GBR2

So exactly how will it work? Is the throttle stick activation point adjustable? I think a lot of people would be interested in a 9303 version for sure. Would need to know where to easily find the power and ground points.

Recieved, thanks. If you can, could you measure the voltage from the throttle at it's lowest point. I want to make sure they are similar. The Spectrum's throttle at it's lowest point is 1.0volts. I use this setting as the reference. If it's above this voltage I turn on the timer. If yours is different then I would have to change the reference in software. You measure this by having the negative of the meter connected to battery ground and the positive end of the meter connected to the center position of the pot. When you move the throttle it should vary.

Kin

Originally Posted by Kevin Murray

I'll only PayPal for one, try one first.
The switch and potentiometer should be the same standart for Jr/Spektrum but the 9303 being more feature packed I need to see it that boadr will physicaly fit into the transmitter case ... so I'll only get one.

PayPal sent.
km

Originally Posted by kfong

When the throttle moves from it's lowest position, it sets the timer to start. I kept it simple for now. I have no need for any point adjustment. In order to do that I would have to put an external switch. It would be pressed when throttle is in the set position. Is there a need for this?

...

Kin

No, In my opinion an adjustable set point in not nessicary,
as long as the timer can not start from the high end extreme of throttle trim.
The adjustable set-point on the Futaba in my opinion unnessicarly complicates things. But even with it Futaba timer beats JR ... Kin's board will help equalize things.

Originally Posted by kfong

Recieved, thanks. If you can, could you measure the voltage from the throttle at it's lowest point. I want to make sure they are similar. The Spectrum's throttle at it's lowest point is 1.0volts. I use this setting as the reference. If it's above this voltage I turn on the timer. If yours is different then I would have to change the reference in software. You measure this by having the negative of the meter connected to battery ground and the positive end of the meter connected to the center position of the pot. When you move the throttle it should vary.

Kin

I'll measure it and PM it to you.
Please just mail me what you have.
I can't beleive the JR engineers would make such a bonehead move as having different zero throttle voltages in their radio line.
We'll find out

Update on the spectrum timer mod.

The mod is not perfect since it can be confused with the start-stop sequence while changing functions as I have found out this past weekend.

There isn't a way for me to access the transmitters software, because of this my mod only knows the position of the throttle stick and presses the start - stop timer button when the throttle is above or below a certain setting. If you play with the timer button to access settings such as switching planes, then the known state can be lost.

When it gets confused then it works just the opposite, throttle up stops the timer and throttle down continues it, this is only when you mess with settings and don't start from fresh start. I've been happy with it as long as I remember to reset the timer from the start by hitting the clear button or use the transmitter after a fresh power up.

For example: One thing you don't want to do is hit the start button, then use the throttle function. This will start the timer mode in the wrong state, since moving the throttle up will now stop the timer and down will start it. I hope this make sense, since my timer mod and the DX timer functions operate independently from one another, and once you have this mod it will interfer with the DX timer, unless you add an external switch to turn the mod off.

Kin
http://www.embeddedtronics.com/