eZ430-RF2500 with the MSP-EXP430FR5969

[tindel 0]

I was planning on creating a datalogger with the FR5969 eval kit with the option of using the RF2500 to transmit the data via RF to a computer.  The FR5969 does have a eZ430 port that I've soldered the 0.5" header at connector J21. I assumed that the RF and FR5969 would be able to talk to each other directly, but it appears that the TX lines and RX lines on both cards are tied together, not cross connected like I had hoped!

 

Any ideas on how to get the RF chip talking to the FR5969 and vice versa?  I did do some google searching and didn't really find anyone that has successfully done this.

 

Am I missing something?

[greeeg 460]

The connector you are referring too is actually designed as a programming header FROM the FR5969LP.

Allowing the EzFET at the top of your 5969LP to program the RF2500.

 

I'd recommend hooking it up externally using something like jumper cables.

 

Or you could run the wireless stack on your FR5969 and connect directly to the cc2400 wireless I on the RF2500 using SPI from the 0.1' headers.

[tindel 0]

Thanks greeeg for the reply.

 

That's what I was afraid of.  Something still doesn't make sense though... can you have two devices on the SBW programing interface?  The eval board doesn't have a good way to isolate the RF2500 from the FR5969... not that I can see.  Another idea I had... Is there a way to get the EzFET in a loopback mode so that I can communicate indirectly through the EzFET?  I suppose I could have the computer in the application UART loopback, but that defeats the purpose of my remote connectivity.

 

It also appears that the EXP430G2 has provisions to have the target (G2553, in my case) communicate with the EZ430... or so the user's guide says... the SBW interface of the EZ430 is conneccted to the emulator side of the isolation jumpers which makes sense because you can isolate the intended target.  The problem here, as well, is that the RX of the EZ430 is tied to RX of the target... and the same can also be said for the TX lines

 

I just feel that there's something I'm still missing... I really liked the elegance of having the RF interface connected through this nice connector and now it appears that it can't be done.

[tindel 0]

I think this is what I'm missing, but I don't quite understand what it's saying... from the EXP430G2 user's guide:

 

"The application UART, on the other
hand, is connected directly to the LaunchPad target device, and jumper J3 can be closed to monitor the
transmission from the LaunchPad target to the attached eZ430. This way both possible connections, from
the device to the PC and from the device to the eZ430, can be established without changing the direction
of the UART pins"

[zeke 693]

@tindel: To connect the RF2500 to the RF5969, you would have to wire it into the LaunchPad's 20 Pin interface. 

The serial port for the FR5969 LaunchPad is located on pins J1:3 (RXD) and J1:4 (TXD) which is the leftside connector on the LaunchPad.

 

Then you can program and operate it as you desire.

[tindel 0]

I was finally able to figure out how to do this... it was pretty easy... I've started with the G2553 demo board and setup the device for software UART.  It's working great.  There is an example in MSP430ware that shows how to bit-bang the data out of the chip (msp430g2xx3_ta_uart9600.c).  Once I modified the code for my use I was getting the TX out of the G2553 'UART RX' pin.  Only took me a few hours once I figured out what I needed to do.

 

The downside is that it takes another timer... or two depending on if you want TX / RX or both.

 

I plan to port my code over to the FR5969 demo board next to take advantage of some of that chips benefits.