Does anyone use the LynxMotion ALD5 robotic arm with unit 3.3.4a Handshaking? When we put 2 of these together per the instructions in PLTW, Our sending robot is sending a signal from pin 15. The signal is sent into the breadboard that contains the 4N25 chip. The board is wired per the wiring diagram provided. When the input signal wire is plugged into the receiving robot’s input A, the robot arm droops as if it has lost power. The receiving robot does nothing when the output is sent and won’t move if manually triggered when the input is plugged in. We have tried different control boards, chips, wires, etc. and none have given us a remedy to the problem. Nothing we do so far has made a difference. The receiving robots still does not indicate it is receiving the signal. Looking for help please.
wiring diagram for lynx handshake.docx (452 KB)
Hi,
Aside from the right-side having a floating digital input (imagine your optocoupler’s output transistor as the switch) when not in use (different issue), you seem to have a short in your circuit if connecting the receiver SSC-32 to the circuit and it causes it to stop functioning.
The main evidence for this is the robot arm acting as if it has lost power. Most RC servomotors (including those in the AL5D) go limp if they do not receive a RC control signal. The SSC-32 stops sending this signal in only a few cases, such as when it is not powered or when you specifically tell it not to send it. If you are simply connecting a wire to an input on the board and it causes this, you are most likely causing a short or other electrical issue on the SSC-32, causing it to no longer send the proper signal.
The best would be to add pictures of your actual setup. While the wiring diagram shows what is expected, it does not show what you are actually using and how it was connected. Make sure to show all components clearly in your pictures (SSC-32s, power cables, jumpers, all wires, the breadboard and its components, etc.).
We await your reply to further help you.
Sincerely,
Thank you for responding. I am attaching 4 pictures to show the issue we are having. We are not sure where we could be shorting out. We have tried replacing the SSC32 boards on both units, the batteries, wiring, optocoupler, etc. We tried it with other arms we have, nothing seems to be working.
Hi,
At a first glance, it seems your sender and receiver are the same image! You may want to edit your post and fix that.
Also, a few other points to look at:
- Do both arms work properly when used individually?
- When used individually, does the input A on the “receiver arm” work as expected, to? What about the other 3 inputs?
- We noticed you have VL=VS jumpers on. Please try with those removed on both SSC-32
- Which software are you currently using? Is it the newest FlowArm PLTW (version 4.0.0.0)? If so, it may have a compatibility issue with the SSC-32. Please try using the attached version instead. This is a special version just for the SSC-32 only (not the SSC-32U, which should just use the regular download from RB-Dsp-11). Simply download this executable and place it in your FlowArm PLTW folder.
Let us know how that goes.
Sincerely,
FlowArm PLTW 4 - SSC-32 version (4.3).exe (2.83 MB)
Thank you for the reply. I corrected the picture for the receiver. Yes both arms worked well independently as we have several projects such as recording a sequence that lead up to the handshake.I will have to check on the other items in your response tomorrow during class, i will remove the jumpers on the sender board as we removed it on the receiver one and I have also downloaded the software you attached. Hopefully we can find a resolution. Thank you for helping!!!
Hi,
Thank you for the extra info and update image.
It does seem like you are creating a short on the receiver end. See the following annotated image of your setup:
You will notice in it two zones, a red one and a purple one. The red one (where you currently have your “input A” signal connected) is actually a series of VCC & GND connections, typically used to power external sensors or provide a common ground to prevent noise in sensor/input signals.
The purple zone is where you actually want to connect the input signal coming out of your optocoupler chip on the breadboard.
Currently, you have the output of the optocoupler connected to the VCC of the board and it’s other side of the transistor to the GND of the board. Therefore, the board is shorted at that point, risking potential damage to the board, optocoupler and of course cutting off power everywhere else (electronics of the SSC-32, servomotors, etc.).
Simply move over your input A signal to the purple zone and it should now work properly.
Sincerely,
Thank You so much!!! We will try it today. You are the best!!!
I am having the same problem with my lynx to lynx handshaking. I am using the old serial boards. I tried clicking on the FlowArm PLTW 4 - SSC-32 version (4.3).exe that scharette listed above and it tells me page is not available. Any suggestions? Thank you for your help.
Hey,
Since that post we’ve changed over to a new community website (this current one!) and the link was lost in the transfer. I’ve updated the link above.
The link still seems to function if you “middle click” it (using Chrome here) or right-click it and select “open link in new tab” (or similar option in your browser).
Here is the link again for reference.
I hope this helps!
Sincerely,
WOOO HOOO!!! Thank you