LM239 response upon change of input from -1.5V to 1.5V (prova.spice)
ngspice
source prova.spice
run
plot v(p1)
Here it is the result:
- Some Spice stuff reference
- Some transistors configurations
- Supercool examples
- Engine control
- Mappa pin Rpi
- Online circuit simulator
- Useful libraries for Eagle
- Astable multivibrator link
Based on this documentation, here it is the scheme proposal.
Based on the first tests, it results that:
- The steering motor absorbs a lot of energy: by turning left or right the motor speed slows down
- RPI does not have any PWM to control the power towards the steering engine
a solution could be to implement a separate oscillator that provides the necessary input to the EN3-4 for the L293DNE. Since we do not need to control the degree of steering, we can set the frequency to a specific value. This Spice example shows an implementation of an astable multivibrator that does not require any integrated circuit. The output voltage is the following:
