no ARMs for D-Rex

[warm38]

Am I reading this totally wrong, or does the D-Rex NOT play nicely with the Plug-A-2138?

I'm familiar with the LPC213x family, which is why I got it. (Besides I don't do Forth.) I thought it would be great to have the D-Rex run with the ARM.
So now that I have some time, I finally started setting it up to talk to the D-Rex -- until I started looking at the pinouts.

I do not see any way for the Plug-A-2138 (or any other ARM) to work with the D-Rex without MANUALLY working the Left Hbridge.

J2 Pin 13 D-REX Hbridge 2 (left) matches with the 2138=J1 Pin 13
Possible LPC pin select uses (does NOT include Match or PWM)
P0_26 GPIO
P0_26 AD05

J2 Pin 14 D-REX Hbridge 2' (left) matches with the 2138=J1 Pin 14
Possible LPC pin select uses (does NOT include Match or PWM)
P0_25 GPIO
P0_25 AD04
P0_25 DAC


Match or PWM available to the ARM

Possible
LOCATION PORT CURRENT USE PWM/M D-Rex Use
--------- ----- ----------- ----- ---------
J1 Pin 1 P0.0 SOUT TxD0 PWM1
J1 Pin 3 P0.1 SIN RxD0 PWM3
J1 Pin 9 P0.28 M0.2 Hbridge1
J1 Pin 10 P0.27 M0.1 Hbridge1'
J1 Pin 11 P0.3 I2C M0.0 /Enable1
J1 Pin 12 P0.29 M0.3 /Enable2
J1 Pin 15 P0.5 SPI M0.1
J1 Pin 17 P0.9 EINT2 PWM6 Encoder1A
J1 Pin 18 P0.7 EINT1 PWM2 Encoder1B
J1 Pin 21 P0.17 M1.2
J1 Pin 22 P0.19 M1.2
J1 Pin 23 P0.18 M1.3
J1 Pin 24 P0.20 M1.3

J5 Pin 2 P0.3 I2C M0.0
J5 Pin 9 P0.8 AD11 PWM4 CurrentMonitor Motor1
J5 Pin 11 P0.12 AD13 M1.0 Vin
J5 Pin 14 P0.13 M1.1
J5 Pin 15 P0.22 M0.0
J5 Pin 16 P0.21 PWM5

P0.16 M0.2
-------------------------------------------------------------


It seems like a big waste of money to get something that doesn't work together. Shouldn't there be a disclaimer on the D-Rex: "does not work with ARM processors"? I had the Plug-A-2138 and was told "you can get the D-Rex and have a dual Hbridge for it." So I ordered it. And now I know I can't. Or, not very easily.

Are there any plans to fix the Plug-A-2138 or have a compatible D-Rex or have a conversion board?

What can I do with a useless D-Rex? Run a bunch of jumper wires to make things line up (I'm not a PCB designer/maker)? How long can they be? Since I'm not an analog guru (I can just barely get by with digital stuff) I hope there's no capacitors or such needed by the jumper wire jungle.

wade

[RMDumse]

Hi Wade,

Yes, we are checking into the issue you bring up. Most doing motors has been using the Pod's because they have superior motor control features, like the quadrature decoding the ARM's don't have. But we see your point. If you have an ARM, the 4 PWM's don't route to the right place to be easy to use with the D-Rex. We're looking into this to see what the best solution would be. Give us a couple days to look into it.

As always, we'll do our best to make you happy. We can certainly take the bridge back if nothing else appeals to you.

[warm38]

I would prefer some sort of a conversion board to route the signals so that they "play nice" with the D-Rex. (PWM going to the Hbridges and Timer Capture or EINT going to the encoders) I have a few projects involving motor control, so I'm hoping to get one working so that I can use reuse my work for the others.

I can always revert to using a couple of my NMIH-0050 units, but I like the 2 extra Amps on the D-Rex.

In either case, the Plug-A-2138 won't hook up easily to anything as it is. I can just as easily use the Rowley Crossfire_2138 or some other small ARM board (other than the NMI TinyARMs which don't five access to the other PWMs).

Let me know how you decide to resolve the ARM/D-Rex situation

[RMDumse]

The idea we are now exploring is making an adapter board with two stacks accomodated side by side. This would allow scrambling of some wires, such as the PWM lines. Also it would allow us to route an additional CS to the SPI pins, so more than one device could be on the SPI.

But it means the base board with the Pluga2138 and DRex would be side by side, and therefore quite a bit wider.

How does that appeal to you? Thoughts?

[warm38]

But it means the base board with the Pluga2138 and DRex would be side by side, and therefore quite a bit wider.

How does that appeal to you? Thoughts?

I could live with that.

The Pluga2138 doesn't have header sockets for stacking, so will that enable GPS or Zigby for future expansion?

[RMDumse]

You can get any of our PlugaXXX CPU's with stacking connectors by asking for the PlugaXXXS (for Stacking) version.

Yes, even a downward pin facing Pluga board could be extended with the new adapter we are now working on. LC and I discussed it again first thing today. We're experimenting with layouts now.

[warm38]

Any word on the adapter board for the non-stacking PlugaARMs?

BTW, any additional examples of code for the PlugaARMs? Is there a separate forum for that topic?

[nmitech]

warm38, below are the signals on the Pluga2138 that i will use for the Drex adapter board. Please Let me know what you think before i make the prototypes.

J2
(1) (2)
(3) (4)
(5) (6)
(7) (8)
(9) HBridge1(P0.7/PMW2) (10)HBridge1*(P0.21/PMW5)
(11)Enable1 (P0.26) (12)Enable2 (P0.25)
(13)HBridge2(P0.8/PMW4/TXD1) (14)HBridge2*(P0.9/PMW6/RXD1)
(15) (16)
(17)Encoder1A(P0.22/CAP0.0) (18)Encoder1B(P0.27/CAP0.1)
(19)Encoder2A(P0.28/CAP0.2) (20)Encoder2B(P0.29/Cap0.3)
...
...
---------------------------------------------------------------
J8
(1) (2)
...
...
(9)CurrMon Motor2(P.012/AD1.3) (10)CurrMon Motor1(P0.10/AD1.2)
(11)Voltage Vin(P0.15/AD1.5) (12)Voltage Motor(P0.13/AD1.4)
...
...


You can use this forum to discuss about the TiniARM & Plug-an-ARM.

[warm38]

Sorry I've been away for so long. I found AVR boards easier to work with. Now I'm trying to get my ARMs working too.

Your pin outs look OK to me. I never came back to this forum until now, instead I was looking at "New Prod" for a D-Rex adapter. I assumed the project was insignificant and dropped.

I guess I can always do a "dead bug" wired interface just to use the D-Rex.