I currently have that board sitting on top of a PhantomX Hexapod to test it out. So far everything is working. If I make a second version there are somethings I will change, like move to a 5mm power connecter instead of the 3.5mm. Also for Dale, added on an I2C connector that is the same as Botboarduino. Would possibly update which of the pins I can choose to pass different voltages to. Maybe allow more of the Analog side to allow VS. Other parts which do, remove. In particular the A10,11,14 are analog and output only and can only handle 3.3v.
Still need to more testing of it, but I am able to control the AX servos, play sounds, use the XBee, and detect the battery voltage, which were some of the main things I was wanting for this purpose…
Started to play with it to see how well it can handle Hobby servos. Looks like a couple of valid ways. They have updated the Servo Library to work with the Teensy 3. With default maximum of 12 servos. Can potentially bump number up, but that could cause the servo cycle to get longer, which if too long servos will complain…
If you have 12 servos at center 1.5ms, then the 12 servos would take 18ms to output, which is under 20ms, so you get the 50 refreshes a second. But if they were all at the defined MAX of 2.4ms, we would take about 28.8ms, so we could only refresh about 34.7 times per second.
Another approach is to use the PWM pins. I have experimented some and it also looks valid. They have added a few extra commands to help make this easy:
analogWriteResolution(res);
analogWriteFrequency(pwmPin, FREQ);
May experiment more later with this.
Many thanks, Kurt! Are these boards difficult to build? If you decide to go to the next revision, I might like to talk to you about getting a board from you. I am really liking the Teensy3.1 so far, with TeensyDuino, and am looking into what it would take to get the W.A.L.T.E.R. 2.0 stuff to run on it.
You know how much we usually need more analog inputs than we have… I’m always in favor of having more.
This is great progress!
Could you try bumping the number up in multiples of 4, and see where it breaks?
RC Servos:
There are a few threads up on the Teensy forum about servos including: forum.pjrc.com/threads/23967-Rec … sy+3+servo
You can increase the number, but some servos may start to lose power when they are not refreshed often enough. But then again if you are using hitec digital servos, than it probably does not matter as they will hold the current position until they get the next update. For myself, not sure if I need more. My guess is that for most future projects, I will probably move away from the RC servo, to something like the Robotis Servos: AX-12 (3 pin serial).
My question to myself, is that currently I have it set up for the Half duplex AX-12’s (and similar) servos. But should I do like I believe Xevel did with the USB2AX board(robotshop.com/en/herkulex-dr … ifications), possibly others. But again I don’t have any of these, so…
As for hard to assemble, depends on if you like to solder or not. On this board, I made all of the smaller components, larger than on previous boards. SMD 0805 -> SMD 1206, but that is still rather small. I have two soldering units. The better one (Weller WSL) , I keep with a fine tip and use it to solder all of the small components. The 2nd (HakKo FX888), I have a larger tip on that I solder on the other things like the connectors. Could potentially go to mostly through hole components, but I got used to assembling these types of boards, as long as I don’t have to do something like the processor chip, that has lots of small close together IO pins.
I’m always in favor of having more.