FOSSASystems / FOSSASAT-1B

Second Generation 1P Satellite
https://fossasystems.github.io/FOSSASAT-1B
GNU General Public License v3.0
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Deployment sensing #2

Open rmely opened 4 years ago

rmely commented 4 years ago

I am not sure how the deployment circuit works, as the schema is not available, but I believe it is a MOSFET driver to burn the wire. My suggestion would be to add a resistor with low value and good dissipation between the MOSFET input and the battery, creating a potential difference between the battery, where it would be possible to measure the current passing through the driver using an MCU ADC.

First, with this value it would be possible to know when the wire is broken, thus enabling the PA that would have been disabled until then. Mechanical or optical sensors on the panels would also be interesting. Also send this information to the GS.

Second, with this value it would be possible to define the duty cycle of a PWM that would control the MOSFET, creating an overcurrent protection circuit and a constant current on the wire. So replacing the code and functionality of the Deployment_Deploy () function; This code should be driven by an interruption.

As a backup measure, the values ​​for decision making should be saved in the EEPROM and be subject to change via GS.

Thank you for your attention and work on this project. Rodrigo Ely

jgromes commented 4 years ago

@juliantech5 thoughts on this?