MSP430FR2355: Programming MSP430FR2355 using UART BSL

Hi Swetha,

Swetha Samay said:

I am trying to program MSP430FR2355 using UART BSL through the BSL rocket/scripter. But it gives [ACK_ERROR_MESSAGE]Unknown ACK value! Attached my files. Please let me know where I am going wrong.

I'd double-check your hardware connections. You can find them listed in Section 4.2 in the MSP-BSL Bootloader (BSL) Programmer for MSP430™ and SimpleLink™ MSP432™ MCUs user's guide.

Swetha Samay said:

Also if I want to use I2C BSL, do i need to have pull up resistors for the SCL, SDA lines? The launchpad for MSP430FR2355 does not seem to have them. Thanks!

I copied this NOTE from page 5 in the MSP-BSL Bootloader (BSL) Programmer for MSP430™ and SimpleLink™ MSP432™ MCUs user's guide.

I2C communication requires pullup resistors on the SDA and SCL lines. The pullup resistors can be soldered on the MSP-BSL PCB (see Section 4.4), or they can be included in the target application design; for example, by adding jumpers to the I 2C pullups on the MSP430 or MSP432 target socket board. TI recommends pullup resistors of 2 to 4 kΩ.

Regards,

James

Thanks for the information. Regarding the I2C BSL, I plan to solder the resistors on the MSP-BSL PCB.

So I should be connecting a pull up resistor to pins 1 and 9 on the MSP-BSL PCB. But in the bottom schematic I see R10 that I can add for the SDA line but I don't see any placeholder for the pin 9 SCL line. Please let me know if there is a way to add the pull up resistor to the SCL line on the MSP-BSL PCB.

Hello Swetha,

What you're describing makes sense, but I think Olimex overlooked what pins are connected to those two pull-up resistors, R10 and R11.

I downloaded the MSP-BSL source code and noticed that P4.5 (BSL-TX) is port-mapped to PM_UCB0SDA in the 'peripherals.c' file. Populating R10 would enable the I2C communication on that pin. However, in that same file, I noticed that P4.0 was port-mapped to PM_UCB0SCL. As you can see, R11 is connected to P4.4, not P4.0.

/*** Initialization of the USCI Module for I2C ********************************/

int8_t InitI2C(uint32_t bitrate)
{
  int8_t ret = 1;

  //Simple port mapping
  __disable_interrupt(); // Disable Interrupts before altering Port Mapping registers
  PMAPKEYID = PMAPKEY;
  P4MAP0 = PM_UCB0SCL;
  P4MAP3 = PM_NONE;
  P4MAP4 = PM_NONE;
  P4MAP5 = PM_UCB0SDA;
  PMAPKEYID = 0;
  __enable_interrupt();

  P4SEL |= BIT0 + BIT3 + BIT4 + BIT5;

  UCB0CTL1 = UCSWRST;                         // Enable SW reset

  UCB0CTL0 = UCMST + UCMODE_3 + UCSYNC;       // I2C Master, synchronous mode
  UCB0CTL1 = UCSSEL_2 + UCSWRST;              // Use SMCLK, keep SW reset

One option would be to modify the source code and port-map P4.4 to PM_UCB0SCL and P4.0 to PM_NONE. This means that your target's SCL connection would be Pin 3 and not Pin 9. Then, you can populate R10 and R11 and everything should work correctly.

A second option would be to add a resistor between the P4.0 and P4.1 pads on the bottom side of the MSP-BSL and configure the software to output a high on P4.1. This would pull up P4.0 and would allow you to use Pin 9 for your target's SCL connection.

The third option would be to just solder a pull-up resistor to VCC somewhere on the board and connect it to P4.0.

The last option would be to do the third option on your LaunchPad.

Perhaps I'm missing something here, but I'll share this feedback with Olimex to see if this can be improved. I hope these options help.

Regards,

James

Thank you for the options. Where can I find the 'peripherals.c' file? Is it in this MSP430BSL_1_02_00_01 folder? Please let me know.MSP430BSL_1_02_00_01.zip