Update of MAX32664 version A internal system

[MartinaMonte]

I am developing a Pulse Oximeter and I have designed my own customized PCB. The PCB has nrf52832 as micro ( MDBT42Q ), MAX32664 version A as sensor hub, MAX30101 optical module and KX122-1037 accelerometer. The PCB connections have been designed following MAXREFDES200 design: both sensors are connected to the sensor hub through SENSOR SCL/SDA, while the sensor hub is connected to the nrf52832 SoC solution via SLAVE SDA/SCL.

SLAVE SCL, SLAVE SDA, RSTN, MFIO pins of the sensor hub (MAX32664) are exposed to update the firmware versione to the latest released (the sensor hub is sold by international distributors with the factory version of its own firmware. It is therefore necessary to update this version to the latest version released). From the MAX32664 datasheet is known that it is possible to do this procedure exploiting MAX32630FTHR and MAX32625PICO. In fact, Maxim provides a firmware image for the MAX32630FTHR that turns it into an msbl programmer for the MAX32664. Basically, by loading the .bin file on the development board through the MAX32625PICO microcontroller, it is possible to transform this board into a programmer for flashing the new firmware to the sensor hub.

The steps I followed are:

• Connect the JTAG Cable from the MAX32625PICO to the MAX32630FTHR, and connect both devices to a PC with a micro-USB cable.

 • Drag and drop the “MRD220 MAX32630 Host FW x˙x˙x ASCII.bin” file in the msbl flashing tools software package onto the DAPLINK drive. The LED on the MAX32625PICO started blinking as it programs the MAX32630FTHR for around 20seconds. The .bin file I used is the one found in the folder "MAXREFDES220_HR_SpO2_Win10_v4.0.0" downloaded from Analog Device WebSite.

• The pins of MAX32664 and MAX32630FTHR have been connected (P3_5 to SLAVE_SCL, P3_4 to SLAVE_SDA, P5_6 to RSTN, P5_4 to MFIO, GND to GND, 3v3 volt to VDD of the custom PCB (which through a voltage regulator brings 1.8V to the sensor hub).

•  Re-connect the MAX32630FTHR to the PC (Windows)

• Opened a command prompt in the directory where there are the executable (“download fw over i2c host.exe” , found in the folder "MAXREFDES220_HR_SpO2_Win10_v4.0.0" downloaded from Analog Device WebSite) and the .msbl ("MAX32664A_MaximFast_A_10.3.0" found in the  "MAX32664A_HR_SpO2_v10.3.0_(1)" folder downloaded from Analog Device, searching for MAx32664 product).

The last passage gives error: "unable to enter bootloader mode, err... -1"

But when I try to enter bootloader mode by code:

    nrf_gpio_cfg_output (mfioPin);    
    nrf_gpio_cfg_output (resetPin);
    
    // Set the RSTN pin low for 10ms.  
    nrf_gpio_pin_clear(resetPin);
    //  While RSTN is low, set the MFIO pin to low (MFIO pin should be set low at least 1ms
    //  before RSTN pin is set high.)
    nrf_gpio_pin_clear(mfioPin);
    //  After the 10ms has elapsed, set the RSTN pin high.
    nrf_delay_ms(10);
    nrf_gpio_pin_set(resetPin);
    //  After an additional 50ms has elapsed, the MAX32664 is in bootloader mode
    nrf_delay_ms(50);
    // Read byte  0x01 0x00 0x08
    nrf_gpio_cfg_output (resetPin) ;    
    nrf_gpio_cfg_output (mfioPin) ;    
  //  Set mode to 0x08 for bootloader mode 0x01 0x00 0x08
  uint8_t StatusByte = WriteByte_cmd(0x01,0x00,0x08,20,mfioPin);
  if( StatusByte == 0) {
    nrf_gpio_pin_clear(LED);
  }
  // 0x02 0x00
  nrf_delay_ms(1000);
  uint8_t ReturnByte = readByte (0x02, 0x00);
  if( ReturnByte == 0x08) {
    nrf_gpio_pin_set(LED);
  }

  // 0xAA 0x80 0x02 0x00 0x15*
    nrf_delay_ms(1000);
  uint8_t s = WriteByte_cmd_16(0x80,0x02,0x00,0x15,20,mfioPin);
  if( s == 0x00) {
    nrf_gpio_pin_clear(LED);
  }
  StatusByte = WriteByte_cmd(0x01,0x00,0x00,20,mfioPin);


It properly does it.

How can I solve my problem? I need to uodate the firmware of the sensor hub.

[Jared]

Hi,

Which SDK version are you using?

The issue isn't very clear but is it that the nRF52 is not sending the expected data over I2C? Have you tried probing the data and clock lines and verified?

regards

Jared

[MartinaMonte]

I am using nRF5_SDK_17.1.0_ddde560. When i download (via SWD from nrf52DK to my custom board) the code (written in SES) to enter bootloader (raising and lowering MFIO/RSTN), it works: I see the LED turning on / off according to the MAX32664 answer.

But, since I need to update the firmware of the sensor hub to use my code, I am trying doing it by using MAX32630FTHR. Doing it, following the steps I described before, I do not get a response from the sensor hub: In particular, this is what I have in the command prompt

The lines are properly powered (I measure 1.8V)

[Jared]

Hi,

"unable to enter bootloader mode, err... -1" is returned from where in the code?

MartinaMonte said:

The lines are properly powered (I measure 1.8V)

I meant that you should double check that the SCLK and SDA lines are correct,

regards

Jared 

[MartinaMonte]

Hi Jared,

SLAVE_SCL is connected to pin 24, SLAVE_SDA to 23 as from datasheet. Moreover, there are pull up resistors (4.7 kOhm).

The error comes from:
    ######### Bootloader #########
    def bootloader_single_download(self, reset):
        print('\nDownloading msbl file')

        if self.enter_bootloader_mode() != 0:
            print('Entering bootloader mode failed')
            return


    def enter_bootloader_mode(self):
        ret = self.send_str_cmd('bootldr\n')
        if ret[0] != 0:
            print('Unable to enter bootloader mode... err: ' + str(ret[0]))
        return ret[0]

    def send_str_cmd(self, cmd):
        length = 0;
        self.ser.write(cmd.encode())
        return self.parse_response(cmd.encode())

[MartinaMonte]

Moreover, I tried, by connecting nrf52-dk to my custom pcb via SWD: to set high / low mfio/rstn and it does it properly; and also to use twi_scanner example and it finds properly the sensors. So my deduction was that everything is properly connected and working