nRF52832 custom target and peripheral initialization problems

[cederom]

Hello world,

I have created a custom target for my design in custom_targets.json accoring to [1]. The goal is to have common firmware repository and code for different product variants / targets based on very similar hardware.

The problem is some pins seems to be somehow already used/declared/initialized for peripherals that I am not using. For instance GPIO that I use as input is always LOW. I cannot use some pins as IRQ inputs, ADC does not show correct values, etc.

Question: How to create a target that will not have peripherals initialized or anything done in the background? I just want to select peripherals and initialize them myself..

Any hints or references appreciated :-)

[1] https://os.mbed.com/docs/mbed-os/v5.8/tools/adding-and-configuring-targets.html

Below is my custom_targets.json:

{
     "my_first_target" : {
         "inherits": ["MCU_NRF52832"],
         "release_versions": ["5"],
         "device_name": "nRF52832_xxAA"
     },
     "my_second_target" : {
         "inherits": ["MCU_NRF52832"],
         "release_versions": ["5"],
         "device_name": "nRF52832_xxAA"
     },
     "MCU_NRF52832": {
         "inherits": ["Target"],
         "core": "Cortex-M4F",
         "macros": [
             "BOARD_PCA10040",
             "NRF52",
             "TARGET_NRF52832",
             "CMSIS_VECTAB_VIRTUAL",
             "CMSIS_VECTAB_VIRTUAL_HEADER_FILE=\"cmsis_nvic.h\"",
             "MBED_TICKLESS"
         ],
         "device_has": [
             "ANALOGIN",
             "FLASH",
             "I2C",
             "I2C_ASYNCH",
             "INTERRUPTIN",
             "ITM",
             "LPTICKER",
             "PORTIN",
             "PORTINOUT",
             "PORTOUT",
             "PWMOUT",
             "SERIAL",
             "SERIAL_ASYNCH",
             "SERIAL_FC",
             "SLEEP",
             "SPI",
             "SPI_ASYNCH",
             "STCLK_OFF_DURING_SLEEP",
             "TRNG",
             "USTICKER"
         ],
        "extra_labels": [
             "NORDIC",
             "NRF5x",
             "NRF52",
             "SDK_14_2",
             "SOFTDEVICE_COMMON",
             "SOFTDEVICE_S132_FULL"
         ],
         "config": {
             "lf_clock_src": {
                 "macro_name": "MBED_CONF_NORDIC_NRF_LF_CLOCK_SRC",
                 "help": "Select Low Frequency clock source. Options: NRF_LF_SRC_XTAL, NRF_LF_SRC_SYNTH, and NRF_LF_SRC_RC",
                 "value": "NRF_LF_SRC_XTAL"
             },
             "lf_clock_rc_calib_timer_interval": {
                 "macro_name": "MBED_CONF_NORDIC_NRF_LF_CLOCK_CALIB_TIMER_INTERVAL",
                 "value": 16
             },
             "lf_clock_rc_calib_mode_config": {
                 "macro_name": "MBED_CONF_NORDIC_NRF_LF_CLOCK_CALIB_MODE_CONFIG",
                 "value": 0
             }
         },
         "OUTPUT_EXT": "hex",
         "is_disk_virtual": true,
         "supported_toolchains": ["GCC_ARM", "ARM", "IAR"],
         "public": false,
         "detect_code": ["1101"],
         "program_cycle_s": 6,
         "bootloader_supported": true
     }
 }

[cederom]

What is more I got this warning in 5.12.3 mbed compile, it seems it was not here before?

WARNING: Custom target "MCU_NRF52832" cannot replace existing target.

[ciarmcom]

Internal Jira reference: https://jira.arm.com/browse/MBOCUSTRIA-1193

[40Grit]

Refer to some of the issues I have commented on this topic. I'm @loverdeg-ep on weekdays.

In the past I recall gpios for some reason being pulled active low by default.

@trowbridgec @theotherjimmy @terminal-sc @AGlass0fMilk @marcuschangarm

[cederom]

Thanks @40Grit / @loverdeg-ep that's exactly what I am experiencing right now too.. :-)

[cederom]

Hey @40Grit / @loverdeg-ep how did you overcome the pulled-low GPIO problem? I will have to solve that one too very soon.. if you have a working solution out of the box I would be more than glad to borrow it :-)

[40Grit]

Sorry, our team has been busy.

I will make a note to take a look when I get into the office today.

@farrenv

[40Grit]

Related MR #7220

What version of Mbed OS are you targeting? Looks like 5.8 from the documentation link?

[cederom]

Thanks for reference!! The problem is still on 5.12.3, but I am using 5.9.7 at the moment because laters have full-mbed-rebuild-each-time problem..

I am initializing the pull-up while declaring the InterruptInt(). Also tried to use mode(), with no change.

One of my pins is SWO.. maybe SWO somehow disturbs the GPIO/InterruptIn? Other pins do not have this problem..

[0Grit]

We have this implemented in our PinNames.h currently.

Still digging; design services has a way of frying neurons.

[0Grit]

https://github.com/ARMmbed/mbed-os/blob/master/targets/TARGET_NORDIC/TARGET_NRF5x/TARGET_NRF52/TARGET_MCU_NRF52840/TARGET_NRF52840_DK/PinNames.h#L254

Yes in your custom targets PinNames.h Change the default pull enum to something less assertive.

[0Grit]

@trowbridgec This is the issue I was referencing this morning. We seem to have gone back to the default of using a PullUp in our target. Keep that in mind if we have any current issues that smell like this.

[trowbridgec]

Ah, yes you have to be careful about that. The only other way I know to set this is to use a DigitalInOut and use the mode() function.