Recommendation of Rabbit Board

Rabbit
1

I’ve been looking at the Rabbit boards, notably the RCM3750, but I have some questions and/or requirements. Currently I’ve been working with an OOPic board with a PIC 16F877 but I’ve ran into some limitations with it.

Basically I’d like to have the following things:

  • At least (3) PWM Outputs to control H-Bridges
  • Serial input for reading from an internal GPS unit
  • Temperature/Humidity reading (future implementation)
  • LCD Control (through serial?)
  • Wireless or Ethernet connectivity (future implementation)
  • Several I/O ports for sensors (proximity, ultrasonic, etc)

I’ve looked at some of the boards and some of the forum posts and have gathered that the Rabbit boards don’t have true PWM output and/or control that say a PIC controller does. Is this true?

What, if any, boards would you guys suggest that would at least meet some of my needs (GPS and H-Bridge are critical)? Also is it necessary to purchase the prototype board or can you plug inputs/outputs directly onto the headers on the core board?

Thanks and sorry for allt he questions!

Kelly K.

2

[QUOTE=xcesmess;438]Also is it necessary to purchase the prototype board or can you plug inputs/outputs directly onto the headers on the core board?

Kelly K.[/quote]

Hi Kelly, if you don’t already have any Rabbit kit, then the prototying boards are excellent value for money. You get the programming cable, Dynamic C, power supply etc. If you use the board yourself, you will need to build a suitable 3.3V power supply, solder to the pins or use a socket or make you own PCB, purchase Dynamic C and the programming cable. I think for most people this is a lot of work and more cost. Best to buy the devkit.

I have all the 3000 based kit but have decided to try out the 4000 devices so I am buying an RCM4000 dev kit as this way I get it all and I can start developing the software before my PCB is ready!!

Hope this helps
Dave…

3

Well that seems to make sense now :slight_smile:

I’ll take a look at those GPS receivers and see if they’re in my price point. I already purchased one from Tyco (A-1035C) and because it outputs either CMOS or SPI but it has this silly micro connector on it that has to be special ordered… not my cup of tea (.1mm x .1mm). That was my reason for considering switching to a Garmin which had a standard wire connector.

One last question… according to the Garmin 15 specs… they say it has the following serial outputs:

CMOS Serial Output Levels
0V to 3.3V (Asynchronous Serial, UART Compatible Polarity)
(from http://www8.garmin.com/manuals/GPS15_TechnicalSpecification.pdf)

Would that unit also be able to hook directly to the Rabbit?

Should be my last question! :slight_smile:

Kelly

4

Thanks for the post Dave. I ended up getting the 3100 dev kit and got a bonus 3110 out of the deal! (didn’t realize it came with two)

Anyway… I’m fighting some issues with finding a compatible GPS receiver… trying to figure out if CMOS and TTL inputs are the same… sigh :slight_smile:

Thanks
Kelly

5

[QUOTE=xcesmess;480]Thanks for the post Dave. I ended up getting the 3100 dev kit and got a bonus 3110 out of the deal! (didn’t realize it came with two)

Anyway… I’m fighting some issues with finding a compatible GPS receiver… trying to figure out if CMOS and TTL inputs are the same… sigh :slight_smile:

Thanks
Kelly[/quote]

Hi Kelly, glad you got it sorted.

For info on the CMOS to TTL stuff try this site. Very helpful and not as complex as you might think.

http://digital.ni.com/public.nsf/websearch/826C981B3D0D3A9786256DD300188620?OpenDocument

If you are building your own kit, just avoid using TTL. I primarily use HCT as this is fast or faster than TTL and no special interfacing. In most cases a pull up resistor will do the job if your signals are not fast edges.!! Have fun.

For GPS check out www.holux.com. Not sure where you are located worldwise but they should have a distributor. There are actually quite a few GPS receivers out there with 3.3V CMOS so this will interface direct to the Rabbit. I use the Holux model in my designs.

Dave…

6

[QUOTE=xcesmess;482]Well that seems to make sense now :slight_smile:

I’ll take a look at those GPS receivers and see if they’re in my price point. I already purchased one from Tyco (A-1035C) and because it outputs either CMOS or SPI but it has this silly micro connector on it that has to be special ordered… not my cup of tea (.1mm x .1mm). That was my reason for considering switching to a Garmin which had a standard wire connector.

One last question… according to the Garmin 15 specs… they say it has the following serial outputs:

CMOS Serial Output Levels
0V to 3.3V (Asynchronous Serial, UART Compatible Polarity)
(from http://www8.garmin.com/manuals/GPS15_TechnicalSpecification.pdf)

Would that unit also be able to hook directly to the Rabbit?

Should be my last question! :slight_smile:

Kelly[/quote]

Hi Kelly,

The Holux GPS uses a standard 2mm pitch dual row connector.

The UART output from the Garmin will connect directly to the Rabbit with no additional interfacing required. You can then simply open a serial port and read the data from it and use the GPS library from Rabbit to decode the contents. Easy!!!

Dave…

7

Sweet…

Looks like I gots me a ‘submit order’ button to click then :wink:

Thanks!

Kelly