Crust Crawler Test bench
Crust Crawler Test bench
by FriedV
Tue Nov 13, 2012 9:19 pm
Hi,
here is my first throw at a little test bench for the crustcrawler hexapod.
Code is in my file space, Crawler1.zip.
Comments, questions & suggestions are always welcome.
Friedrich
here is my first throw at a little test bench for the crustcrawler hexapod.
Code is in my file space, Crawler1.zip.
Comments, questions & suggestions are always welcome.
Friedrich
by FriedV
Tue Nov 13, 2012 9:42 pm
Some more info:
The code is VB2012, running on a Win7 MacBook Air with USB2Dynamixel . Later the code it is planned to be run on a Pokini PC (small and well built, but rather expensive).
The Pokini has WiFi, so this will be used for first remote control. Later this will be done via Zigbee, probably.
Power supply are two Turnigy 3S 4Ah Lipos, one for the servos the other for the Pokini and sensors. I'm working on a device to cut of the Lipos when voltage goes low, a simple warning device is not secure enough, I think.
Friedrich
The code is VB2012, running on a Win7 MacBook Air with USB2Dynamixel . Later the code it is planned to be run on a Pokini PC (small and well built, but rather expensive).
The Pokini has WiFi, so this will be used for first remote control. Later this will be done via Zigbee, probably.
Power supply are two Turnigy 3S 4Ah Lipos, one for the servos the other for the Pokini and sensors. I'm working on a device to cut of the Lipos when voltage goes low, a simple warning device is not secure enough, I think.
Friedrich
by FriedV
Thu Nov 15, 2012 4:03 pm
Some more info:
I tweaked the schematic above to get some more reliable operation:
s2 Lipos : R4=10k, R8=4k7, Tr1 fixed(R9) R=1k3 turn-off-voltage ~6.15V
s3 Lipos: R4=1k5, R8=4k7, R9=3kturn-off-voltage ~9.2V
I measured the internal resistance at TL7705 sense input to be ~18k,
switching level about 4.5V.
So you can do you own calculations.
BTW I used VeeCAD to make a quick & dirty stripboard, I can really recommend this little util for fast prototyping. Results see pics 3&4.
And mind the rather hight currents, therefore I added some extra thick wires to the board!
Here are some pics
Friedrich
I tweaked the schematic above to get some more reliable operation:
s2 Lipos : R4=10k, R8=4k7, Tr1 fixed(R9) R=1k3 turn-off-voltage ~6.15V
s3 Lipos: R4=1k5, R8=4k7, R9=3kturn-off-voltage ~9.2V
I measured the internal resistance at TL7705 sense input to be ~18k,
switching level about 4.5V.
So you can do you own calculations.
BTW I used VeeCAD to make a quick & dirty stripboard, I can really recommend this little util for fast prototyping. Results see pics 3&4.
And mind the rather hight currents, therefore I added some extra thick wires to the board!
Here are some pics
Friedrich