MOD-PULSE computer connection

zooox · November 10, 2016, 11:33:13 PM

Hello,

We recently bought the MOD-PULSE board and the MOD-USB-RS232 to run the Pulse Oximeter application made by TI. Currently, the board is being powered by an external source, and we are using the MOD-USB-RS232 to connect to the computer. We know the board is properly powered and working because it displays readings on the LCD.

We followed TIs instructions on driver and VI installation. However, despite the drivers apparently installing correctly, we still don't see a waveform on the VI. We selected the correct COM port, and made sure to install Labview Run Time Engine.

We're not sure what to try next. What else should we do?

Thanks

LubOlimex · November 15, 2016, 04:49:34 PM

Hey,

Did you configure the SMT jumpers to swap RX and TX on one of the boards? By default both MOD boards have TX and RX at the same pins at the UART connectors. Either change the jumpers on MOD-PULSE or those on MOD-USB-RS232 (this action requires some previous soldering experience and cutting and soldering).

Best regards,
Lub/OLIMEX

zooox · November 17, 2016, 06:39:23 AM

Thanks for the response.

We have not changed the jumpers on either of the products. We assumed that since we found a way to externally power the board that it would be unnecessary, but we'll try it anyway. Would doing this allow the board to communicate with the Labview VI?

LubOlimex · November 17, 2016, 03:57:24 PM

Yes, you need to change the posisiton of the jumpers on one of the boards. This would make the visualisation working.

The thing is that both boards carry the "MOD" prefix. Both boards are considered "slave" boards. They are meant to be connected to boards without the "MOD" prefix. When you attempt to connect two "MOD" boards together there is a problem with the RX line of the first board going to the RX line of the second board and TX lines also meeting TX. This means collision on the data signals of the serial interface.

If you change the jumpers position on one of the boards RX would go to TX and TX would go to RX which is the proper way.

Best regards,
Lub/OLIMEX

zooox · November 17, 2016, 09:26:29 PM

Ok, we are looking at the MOD-USB-RS232, we see pads for 3_Rx/3_TX and 4_Tx/4_RX, it does not look like there is a connection that needs to be cut. Is this true? Which pads do we need to solder? (Picture attached) http://i.imgur.com/pC1TdrB.jpg

Thanks for your help.

LubOlimex · November 18, 2016, 08:20:03 AM

There is a visible connection. It is board mounted wire between the pads. Refer to my picture on where to cut. It is a good practice to use a multimeter tool and measure for short circuit between the pads that you need to disconnect (if the unit beeps you didn't separate the connection, cut again). Again it is a good idea to use multimeter tool in beep mode after the soldering to confirm that you didn't oversolder all pads together.

The pictre is here: http://i.imgur.com/b8Vnadr.jpg

Best regards,
Lub/OLIMEX

zooox · November 18, 2016, 07:13:22 PM

We got it working. Thanks for your help!

zooox · December 12, 2016, 08:13:40 PM

Hey LubOlimex,

We have successfully been able to reprogram the board using a external debugger and flash programmer. We're currently trying to reprogram the MOD PULSE board with a modified version of the provided C code .(https://www.olimex.com/Products/Modules/Biofeedback/MOD-PULSE/open-source-hardware in the "Mod Pulse Demo Software")

I understand that you used IDE, but we are using Code Composer. Are there any specific libraries that you included? Is there anything we should know about this process with Code Composer?

Thanks

LubOlimex · December 15, 2016, 09:56:01 AM

This would probably require a lot of experience with CCS and re-writing the demo from scratch. Still, make sure to use the IAR demo as a basis.

If you are in a hurry, I would recommend using the time limited evaluation version of IAR for MSP430, instead of CCS.

Best regards,
Lub/OLIMEX

zooox · February 17, 2017, 11:05:46 PM

Hey Lub,

We have successfully uploaded the source code provided for the MOD-PULSE to the microcontroller without any changes to the code. However, the LCD display is not working properly (http://i.imgur.com/Nzo7ROH.png). We used a Texas Instruments MSP-FET430UIF debugger instead of the Olimex one. Could this be a potential reason why the LCD is not working?

Thanks,
ZooOx

LubOlimex · February 28, 2017, 04:31:54 PM

This shouldn't matter as long as the connection is properly established. The problem is somewhere else. Maybe the two power supplies from the JTAG and the battery meet. Can you try powering only from the JTAG (disconnect the battery)?

Did you check with different position of the power jumper?

Is this during debug?

Best regards,
Lub/OLIMEX