Servo Timer II
Posted: Thu Jun 30, 2011 1:53 am
Hi everyone,
We've been working on the next iteration of our servo timer over the last few months, and after much procrastination it's finaly finished.
Some features include:
* 6 - 9V operation. (see Power note below)
* Single RC servo output - Can drive most common RC servo motors up to ~1A for short periods.
* Configurable servo START and END positions - Allows you to customize how far and which direction your servo motor will move.
* 0-12 second delay selectable in 1 second increments - Simple rotary switch interface.
* Built in 2G acceleration switch for launch detect - No need for any external components. Just plug in a servo and battery and you are ready to go.
* External make or break wire trigger - You can directly connect other mechanical switches with normally closed or normally open contacts, custom trigger mechanisms, pressure switches etc. to trigger the timer.
* External 3V - 12V hi/low trigger - You can connect most existing rocket flight computers, altimeters, magnetic apogee detectors with pyro or digital outputs directly to the timer without additional interface hardware.
* External timer output - You can drive other external circuits when the timer activates.
* High-brightness 'ARMED' status LED visible in broad daylight from over 50 feet away. - You can see that the timer is armed from a safe distance before launch.
* Timers can be cascaded - You can easily connect any number of the timers together for more complex functionality. One timer can control a drogue parachute, while a second can deploy the main parachute. Or use one for a staging mechanism that triggers a second to deploy a parachute after staging.
* Timer self ARMs after 5 seconds after power on, Or can be configured for manual ARM.
* ICSP connector for firmware updates
* Weight: 6 grams
* Dimensions: 25mm x 43mm (1 x 1.7 inches) - The small footprint allows it to comfortably fit inside T8 FTC rockets.
Power: Although the timer will run from lower voltages, you need to be careful as a regular servo's torque and speed will be reduced and may cause problems with the reliably of the deployment mechanism. If you are after weight and space savings you can make a 2S pack from two of these 70mAh 20C LiPo batteries:
http://www.hobbyking.com/hobbyking/stor ... oduct=7566
Each of these batteries weighs a mere 2 grams and can deliver a whopping 1.4A. We use these with our timers. When weight isn't an issue then just clip in a regular 9V battery, or a battery pack made from single 1.5V cells.
We've done close to 20 flights with these timers now ranging from small slow rockets to big fast ones. We've also been using them with the uMAD from Whooshtronics for apogee detection. It serves as a good back up deployment mechanism while you test out your own system.
With the release of this version, we are also making the .HEX file and PCB layout files available on request for the previous version ( V1.6 FC - ) If you prefer to build the timers yourself.
Cheers
- George
We've been working on the next iteration of our servo timer over the last few months, and after much procrastination it's finaly finished.
Some features include:
* 6 - 9V operation. (see Power note below)
* Single RC servo output - Can drive most common RC servo motors up to ~1A for short periods.
* Configurable servo START and END positions - Allows you to customize how far and which direction your servo motor will move.
* 0-12 second delay selectable in 1 second increments - Simple rotary switch interface.
* Built in 2G acceleration switch for launch detect - No need for any external components. Just plug in a servo and battery and you are ready to go.
* External make or break wire trigger - You can directly connect other mechanical switches with normally closed or normally open contacts, custom trigger mechanisms, pressure switches etc. to trigger the timer.
* External 3V - 12V hi/low trigger - You can connect most existing rocket flight computers, altimeters, magnetic apogee detectors with pyro or digital outputs directly to the timer without additional interface hardware.
* External timer output - You can drive other external circuits when the timer activates.
* High-brightness 'ARMED' status LED visible in broad daylight from over 50 feet away. - You can see that the timer is armed from a safe distance before launch.
* Timers can be cascaded - You can easily connect any number of the timers together for more complex functionality. One timer can control a drogue parachute, while a second can deploy the main parachute. Or use one for a staging mechanism that triggers a second to deploy a parachute after staging.
* Timer self ARMs after 5 seconds after power on, Or can be configured for manual ARM.
* ICSP connector for firmware updates
* Weight: 6 grams
* Dimensions: 25mm x 43mm (1 x 1.7 inches) - The small footprint allows it to comfortably fit inside T8 FTC rockets.
Power: Although the timer will run from lower voltages, you need to be careful as a regular servo's torque and speed will be reduced and may cause problems with the reliably of the deployment mechanism. If you are after weight and space savings you can make a 2S pack from two of these 70mAh 20C LiPo batteries:
http://www.hobbyking.com/hobbyking/stor ... oduct=7566
Each of these batteries weighs a mere 2 grams and can deliver a whopping 1.4A. We use these with our timers. When weight isn't an issue then just clip in a regular 9V battery, or a battery pack made from single 1.5V cells.
We've done close to 20 flights with these timers now ranging from small slow rockets to big fast ones. We've also been using them with the uMAD from Whooshtronics for apogee detection. It serves as a good back up deployment mechanism while you test out your own system.
With the release of this version, we are also making the .HEX file and PCB layout files available on request for the previous version ( V1.6 FC - ) If you prefer to build the timers yourself.
Cheers
- George