I’m looking at adding 25 servos to a synchronous telemetry interface manipulator. In total there will be 50 connections, 25 modified pots and 25 running servos.
The synchronous interface will be built and used like a telemetry suit.
This projecy has been inspired by Jims (2008) thread.
I’m thinking my best option is to use an SSC to serve has the host controller and then used two ABB2 with pro28’s as the slave’s.
Questions: Has anybody ever used two ABB’s and one SSC together? can it be done? How would i link these together? Connections and Code?
im guessing the two ABB can have the same program or different programs installed. this shouldnt make a difference as both will have their own output to the SSC.
I’ve not used a SSC-32, does it have two serial connections? I know that the ARC-32 does, so you could hook your ABBs up to one of them. Doubt you want to do that though, knowing the cost to it takes get one over to the UK .
Well i believe it only has one but i was hoping someone more experienced would know of a solution for this kind of connection. maybe i can have the connections run
ABB(#1) p15 > to p14 of the ABB(#2) then p15 > SSC tx/rx
maybe the Code from the ABB(#1) can bypass the ABB(#2) and go to the SSC thought the same Serial as ABB (#2)?
As you mentioned, you could probably use the hardware serial port between the two BB2s and then have the SSC-32 connected up to one of them, who forwarders stuff from the BB2 that is not connected to the SSC-32. For some reason the link you gave to Jim’s thread does not work for me…
But stepping back a little. My assumption is that the 25 real servos would connect up to the SSC-32, but I an sure how you plan to hook up the 25 modified ones. I believe you need to use Analog to Digital IO to read these in. On Bap28 you only have 8 analog capable pins (0-3, 16-19), so using two of these will only get you 16 analog pins. You could probably use a couple of mux chips to have more analog inputs to the BAP. But if you go this route, you can probably simply add 4 of these and get up to 32 and only need one processor board…
yes im very aware of this but also my wife is aware of the price.
i think im going to have to reduce the amount of servos im planning on using. at the moment i have modified six HS-311 servos and i have 11 servos (HS-645’) already built into the project, out of the 25 intended. just need to make room on my desk.
i have been testing the performance and all looks good at the mo.
but as mentioned i will have to reduce this down to 16.
in fact the other option i might have is if i can convert any of the pins on an SSC to input?
i know it has the ABCD inputs but would be able to add others?
i have a few spare SSC’s
would it be possible to have an SSC with all the Mod servos on, and have this run through the ABB to another SSC with the real servos on.? just trying to this out the box? or just being a fool. if so please ignore me.
Kurt’s tip about the MUX is probably the best solution. The 16 channel MUX from SparkFun cost only 4,95$. Or even cheaper the popular 4052 8 channel MUX for only 0,95$ (you’ve to make a prototype board though).
First off you can have two micros sending serial data to one SSC-32, however. Research would have to be done to allow the two outputs to be connected together to drive the same input without damage. It could be as easy as one of the micros set an output pin as a flow control. If it’s in one state the first micro enables the output and sends the data. If the pin is in the other state the first output is set as an input and the other micros pin changes from an input to an output to send the data. This way both of them can’t be outputs at the same time. Solder, my favorite programming language.
I am not sure if you could get away with adding an external Pull Up resistor and using the Open Drain version of the serout command. Don’t know if they work or not…
If so could maybe use one of the IO pins on the BAP that has a built-in PU resistor to talk to the SSC-32. (viewtopic.php?f=4&t=4534)
I think you should have a serious look at using X-Bee’s in a network configuration, they have the potential of being used way more than just a single wireless connection.
I’m not going to rewrite the manual but I have 1 ABBII Pro 28 connected with X-Bee to 1 SSC-32 which has it’s X-bee and at the same time an X-bee connected to the computer.
These are set up in a coordinator/router/router configuration and you literally can have hundreds of devices in a PAN network.
I have the T-Hex setup to operate as a normal PS2 controlled bot with Xbee’s between ABBII and SSC32 and at the same time I have an on-board camera that sends video to my PC running Robotrealm software which in turn sends serial data back to the SSC32 to manipulate ( for now just the pan and tilt camera ) the XBee’s do all the signal routing and coordination.
I look back at this bot ( because I haven’t been active with the bots lately ) and say " How the hell did I do this " but It works perfect every time I turn it on and I think that this setup may be worth looking at on your part.
I will try and put some neat drawings( like you guys do) together and that may help but it will take me some time.
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