Questions regarding robot voltage circuit
Questions regarding robot voltage circuit
by serithseraki
Thu Nov 29, 2012 8:18 pm
I have been looking into creating methods for my nova to display emotional responses based on certain factors. One being the most crucial is battery longevity and his level of fitness based on his current voltage. Currently my nova is still using the default NIMH batteries and MRC3024 control board and I am aware that a simple circuit can be made to read the voltage as described in the back of the manual. Although, I have read in areas of the forum that this does not really work as stated here.
http://www.davidbuckley.net/DB/RoboNova/RoboNova_files/RobotVoltageCircuit.htm
Furthermore, I have seen this modified version here.
http://davidbuckley.net/RS/RoboNova/RoboNovaLV.htm
Although this also does not seem to work very well. So can someone who has done this give me details as to how well it works for you or if any of you have an alternative method that you can instruct me on that would be much appreciated. I want my nova to show varying levels of panic as he approaches power loss but is this even doable?
http://www.davidbuckley.net/DB/RoboNova/RoboNova_files/RobotVoltageCircuit.htm
Furthermore, I have seen this modified version here.
http://davidbuckley.net/RS/RoboNova/RoboNovaLV.htm
Although this also does not seem to work very well. So can someone who has done this give me details as to how well it works for you or if any of you have an alternative method that you can instruct me on that would be much appreciated. I want my nova to show varying levels of panic as he approaches power loss but is this even doable?
by i-Bot
Fri Nov 30, 2012 11:59 am
The battery voltage monitoring does work within the limits described by David. You will see that the resolution in voltage measurement is quite small and the range limited. I would suggest that you use a value around 6 Volts for a good battery when the robot is in the standard pose.
Battery voltage is not a very good measure of battery capacity remaining and is very load dependant. If the battery is at 6 volts in standard pose, it will likely drop below that threshold when making moves. You might be better to count the number of drops below 6 volts during movements.
You might try a large capacitor at the junction of the resistors and the analog input to ground ( best to also have a diode in parallel with other resistor to protect processor on power down). This might integrate the varying voltage.
Battery voltage is not a very good measure of battery capacity remaining and is very load dependant. If the battery is at 6 volts in standard pose, it will likely drop below that threshold when making moves. You might be better to count the number of drops below 6 volts during movements.
You might try a large capacitor at the junction of the resistors and the analog input to ground ( best to also have a diode in parallel with other resistor to protect processor on power down). This might integrate the varying voltage.
by marcel84
Tue Dec 18, 2012 5:44 pm
Battery voltage can never be used as an indicator of battery health. However, you can use a time-voltage slope to determine the battery usage and mAH value along with that to calculate battery health. You can’t find that with a capacitor inductor setup, opto-isolators are required for that. I’m afraid it’s a little more complicated than simply knowing the output voltage of the battery...
circuit board assembly
circuit board assembly
Last edited by marcel84 on Thu Jan 09, 2014 12:22 am, edited 3 times in total.
