Repost: Engel Handy Uniton transmitter

[tiptipflyer]

Reposted from April 2017, this is from Frank, "Tiptipflyer":

The Engel Handy Uniton transmitter replica is ready to go now. It is small in size but big in performance (I hope). The case is real tiny, measuring 90x40x22mm. It features :
- S/C emulation either compound (on channel 1) or sequential (on channel 5),
- kick up elevator on channel 2,
- quick blip throttle with motor status LED on channel 3,
- escapement control on channel 4,
- inactivity alert,
- low battery alert set to 3.5V,
It is powered by a single 300mAh lipo cell using a Pololu step up converter (that thing is real small) to get the required 5V. Charging plug included for easy charging (1cell only).
HF is a 2.4GHz Flysky module without the bind button (not required anymore) and voltage regulator with a stripped antenna. Binding is with the control button connected to the bind input via a diode (thank you Jean Marie for the tip), it works great.
The chip is an ATtiny 85 where the onboard LED can be used to show the motor status.
The small size of the stripped Flysky module, the Pololu step up converter and the ATtiny85 module make it possible to get everything in such a small case for a real palm size transmitter.

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Cheers
Frank

[tiptipflyer]

Thanks to the help and inspiration of Martin and other mates, I finished my first drawing with OpenSCAD, it is an exact replica of the Engel Handy transmitter. It was easier than expected. I started with one of Martins drawings and changed the parameters to get the Handy case.

I will get that printed within the next weeks and will see, if it fits together and how it looks like.
Keep you informed.
Cheers
Frank

[tiptipflyer]

I made a more accurate replica of the tiny Engel Handy transmitter.
It is on 35MHz using a Futaba style module and an Attiny85 as the brain.
It features compound and sequential S/C function , accustic low voltage alert and inactivity buzzer.
Normal mode is compound with quick blip throttle, if you pree the button on start-up it is in sequential mode, but no motor control anymore, just for IC engines or gliders.
The enclosure is 3D-printed. I made the drawing using OpenSCAD.

Frank

[tiptipflyer]

Here comes the same, more accurate replica on 2.4Ghz. It uses an Orange Futaba style module without the orange case and an Attin85 for the programm. It is a two button transmitter, one button for steering rudder and kick-up elevator, and the second button for sequential motor control.
It has low voltage alert, inactivity buzzer and charging plug. Battery is a 9V style Li-Io.
The antenna is a cheap spare antenna from Banggood.
Normal mode is compound with kick-up elevator, if you press the button on start-up it is in sequential mode, but rudder only. Motor control is still available on the second button.
Flight-test is already done using the Schoolboy, no problems, good range, works great.

Cheers
Frank