MSP430F2013 + MAX3100

Development Boards MicroMod
1

http://i204.photobucket.com/albums/bb29 … nfig-1.png

Hey,

I am having issues with trying to get a MAX3100 to work with a F2013. I have the two configured in the image above. The inputs (RX & TX) for the MAX3100 are coming from a MAX232 connected to a serial cable. The MAX232 works in loopback. On my oscilloscope when a key is pressed in the serial terminal i can see the signal coming out of TX of the MAX232 when the MAX3100 is removed. Once the MAX3100 is added back in, its TX becomes 3.6V and RX becomes 5. Nothing comes out of DOUT on the MAX3100.

Any ideas?

Thanks,

Bob

2

Are you sure you’ve got the MAX232 wired correctly? The pin on which received data appears will be R1out or R2out, the pins with names starting with a ‘T’ are for data going in the other direction.

Your circuit won’t work as shown, anyway, without a connection to the MAX3100 /CS pin. Nothing is supposed to come out of DOUT unless clock pulses are applied to SCLK while /CS is low.

3

I used the same setup that is in the [UART tutorial from SparkFun for the MAX232. The output from the MAX232 is 5v while the input to it is ~15v

For the /CS connecting it to GND should drive it low, correct?

Thanks,

Bob](http://www.sparkfun.com/commerce/present.php?p=BEE-4-UART)

4

Gnd can’t be anything but low!

Leon

5

I’m a little embarrassed. Should probably use thought process a little bit more.

6

flow.png1024×372 67.2 KB
http://i204.photobucket.com/albums/bb29 … k/flow.png

Here is the schematic that I currently have.

Thanks,

Bob

7

You need a crystal on the MAX3100!

Leon

8

And you can’t just ground /CS - it has to be toggled at certain points to talk to the MAX3100.

It’s probably not a good idea to leave the /SHDN pin floating, check the datasheet for what should be done with it if it’s not used.

9

FYI, though not to max232 but to a USB chip, this image shows 4 signals from the uCPU to the max3100:

http://www.maxim-ic.com/images/appnotes … 5Fig01.gif

and the app note from maxim:

http://www.maxim-ic.com/appnotes.cfm/an_pk/3025

10

The MAX232 should have two Cs connected to V+ and V-, one to Gnd and one to Vcc. I don’t think it will work with just one connected the way you have done it.

Leon