Wow, nice find!
That will sure to come in handy. I book marked the page. I hope the page does not change as the sometimes do.
Those batteries aren’t made with aluminum. It’s a plated metal. The zinc solder is for LiPos which are housed in aluminum. I only mention it because I’d hate for you to go buy it and see it’s not going to work for the NiMH batteries or solder tabs.
Sorry that I haven’t been keeping up to date; been real busy.
I finally got something working with the batteries.
By taking pieces of plate metal, duct taping them to the battery connections, duct taping the whole set of batteries into a pack, and then cinching a ton of tie downs around the whole mess very tightly-- I finally got something that can hold it’s charge.
So, I can finally get back to programming positions.
With luck, I’ll have a tethered (because of WiPort issues) biped to bring to the next SJRG meeting.
Dan Albert and I are going to be having an informal Robo1 competition, there.
I can’t wait until his KHR-1 punches the serial cable out of the SSC-32.
I’ll have to remember to secure that…
Hm…
Plated metal?
Is plated metal supposed to be so resistant to welding?
If not, then I’ll give it a try again…
Perhaps I wasn’t getting a good ground connection.
Something you might look into:
micromark.com sells a swab-on copper-plating kit (catalog number 83248) that I have used in the past to plate a layer of copper onto hard-to-solder metals. Admittedly, it isn’t an ideal solution, but it’s allowed me to form a useable electrical connection to some weird stuff before. May not be the best thing for a battery pack, from which you’ll be pulling a decent amount of current, but then again, it might work for you.
Whoa! just reading this gives me an upset stomach. 
I will post some images of how to solder to a battery pack tomorrow…
Nick…
I mean…
Nick,
I think the only right thing to do would be to send Jim a big ole bottle pepto-bismol.
Just kiddin buddy.
Tinman
Here is an image of a solder connection to a battery with the solder tabs removed. I forgot my soldering stuff at home, so I actually used a desoldering tool here at work. I used some sand paper to rough up the surface before adding some solder, then I just used the reflow technique to make the connection. The battery was not even warm when I was done. I didn’t clean the flux either. This is a solid connection as you can see it’s quite shiney in apearance. It would have looked a lot better had I remembered my soldering iron. I used some nice 60 40 solder. I never thought about it before, but solder with lead in it may be difficult to get now a days, but it is better than the no lead stuff IMHO.
Uh…
Well, I did that, and I didn’t get the battery hot…
I’m starting to think that it wasn’t my soldering, but was my cheap battery holders.
The same batteries, outside of my holders, soldered directly to wire are working perfectly.
Thanks for the help.
^.^
By the way…
We never really got to competing, at the SJRG.
Too much fun stuff to look at and talk about.
Besides, neither Dan’s or my bot was where we wanted it to be.
Hopefully, we’ll have something more to bring to the table next month.
Sorry about the total lack of recent updates.
Finals have been killing me.
I’ve gotten the WiPort back to where it was before I sent it for diagnosis, but I haven’t been able to progress any farther.
I can talk to the WiPort both wirelessly and through RS232 to my USB port.
I do this on Serial Port 1 because Serial Port 2 is fried.
No suprise there, though, since you all know how handy I am with electronics.
Anyhow, I can talk to the WiPort all I want, but I can’t get it to relay my characters to the SSC-32.
I’ve tried TTL through the WiPort’s Serial Port 1 and into the corresponding TTL pins of the SSC-32.
No luck there, though.
I’m going to try RS232 through Port 1 and into DB9 RS232 header of the SSC-32, next.
Hopefully, I’ll be able to get some luck with that.
If that doesn’t work, I’m going to take a run down to Dan’s house and have him take a look at it with his logic thinger majigger (yes, that’s the technical term for it 
).
If I’m yelling at Serial Port 1, wirelessly from my computer, the WiPort should still be able to export data through Serial Port 1, anyhow, right?
I’ve finally gotten the pressure sensors mounted to the feet, but I screwed up somewhere in the wiring of both.
Upon closer inspection, one (and I suspect the other, as well) of the wires going up to the biped was severed by getting itself caught in a joint.
So, I’ll have to patch that up before I can start working on getting him to balance himself.
I fixed the bugs that I was having with one of the pressure sensing feet (I haven’t started making the second, yet.
Then I wrote the code for it (thanks, Andy, for the kick in the right direction!):
Imports System
Imports System.IO
Public Class Form1
Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
' Manually set the proper timer settings.
Timer1.Enabled = True
' Do the timer sub every second.
Timer1.Interval = 1000
' Manually set the proper serial port settings.
' Stick whatever port number you are connecting to here.
SerialPort1.PortName = "COM4"
' Set the baud rate equal to the baud rate of the SSC-32.
SerialPort1.BaudRate = 115200
SerialPort1.DataBits = 8
SerialPort1.StopBits = Ports.StopBits.One
SerialPort1.Parity = Ports.Parity.None
End Sub
Private Sub Timer1_Tick(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Timer1.Tick
Dim i As Integer
' In PID control, "plant" is the term
' for the object being controlled.
Dim PlantValue(2) As Byte
' Open the serial port.
SerialPort1.Open()
' Go to the subroutine named "RequestByte".
RequestByte()
' Go to the function named "ReadByte" twice.
For i = 1 To 2
' Store the VA and VB value in an array.
PlantValue(i) = ReadByte()
Next i
' Close the serial port.
SerialPort1.Close()
' Remove the below comments to display
' the read data in a text box.
' TextBox1.Text = ""
' For i = 1 To 2
' TextBox1.Text &= PlantValue(i) & " "
' Next i
End Sub
Private Sub RequestByte()
'Send VA VB <cr> to the SSC-32
SerialPort1.Write("VA VB " & vbCrLf)
End Sub
Private Function ReadByte() As Byte
' Store a byte within the varialbe ReadByte,
' and send that variable back to the timer sub.
Return SerialPort1.ReadByte
End Function
End Class
Anyone who wants to can “borrow” it, as with all my posted code.
Now I just have to write a PID algorithm.
Andy linked me to:
embedded.com/2000/0010/0010feat3.htm
The only problem is…
I don’t know what “->” is.
Mike thinks that it’s a reference pointer, but my books tell me that “&” is a reference and “*” is a pointer.
Can anyone provide a link that explains exaclty what “->” is?
Thanks.
^.^
It’s easy Nick, it a pointer like this------>
Lol, such a help, Mike.
The other Mike gave me a site that explains it:
codersource.net/cpp_tutorial … inter.html
But… I can’t make much out of it.
What I got from it was that it’s called a “this” pointer (I suppose it’d be called a “my” pointer in VBE).
And, I believe that it points to a class, instead of a variable.
But… I don’t even understand what I’ve just written.
-.-"
And, from what I can tell, VBE.NET doesn’t support pointers of any type.
Does anyone know a way around using “this” pointers?
Or, can anyone anyone explain what’s actually happening during a “this” pointer execution?
what is “this” pointer, you speak of exactly?
no, it’s not a this pointer. A this pointer would be like My in VisualBasic.
Unless you’re doing C/C++ you won’t need to know the details of this, just know that it behaves very much like a “.” in terms of accessing elements of an object. In the case of the PID paper, its accessing elements of a struct.
If you’re still interested, the difference is what sort of access you have to the struct. If you had the actual struct, you’d access its elements with “.” notation. Instead they have a pointer which they are passing around so the “->” notation means follow the pointer to find the struct that it points at and access the named element. Details such as this are abstracted in most modern languages and you’ll probably never have to deal with it. 
Ok… well I had to figure out what structures were, first (it only took three of my five books ).
But, now, what you said makes a lot more sense.
So, in essence, I can just cut right to the chase and use “.” instead of his arrows, so long as I construct an actual structure.
Any idea why he used something that isn’t very intuitive for a coding example?
Perhaps pointers are a faster way to do it?
well he used C for the example and it makes perfect sense to C programmers. I’ll port the example over to .net and post it sometime today.
public class PID
{
public double dState; // Last position input
public double iState; // Integrator state
public double iMax, iMin; // Maximum and minimum allowable integrator state
public double iGain, // integral gain
pGain, // proportional gain
dGain; // derivative gain
public double UpdatePID(double error, double position)
{
double pTerm, dTerm, iTerm;
pTerm = this.pGain * error;
// calculate the proportional term
// calculate the integral state with appropriate limiting
this.iState += error;
if (this.iState > this.iMax) this.iState = this.iMax;
else if (this.iState < this.iMin) this.iState = this.iMin;
iTerm = this.iGain * iState; // calculate the integral term
dTerm = this.dGain * (position - this.dState);
this.dState = position;
return pTerm + iTerm - dTerm;
}
public PID()
{
dState = iState = 0;
iMax = 100; iMin = -100;
}
}Hello Nick,
Are you still working on the pressure sensors for the foot? Have you tried creating a static walking gait with your humanoid like you did with the scout?