nRF52840 + Wio-SX1262 bootlooping

[overkillthemighty]

I have a Wio-SX1262 that got it's sense connector knocked off the bottom. The button and LED are not accessible, but everything else is connected to one of the header pins on the board. I connected it up to a nRF52840 that has had a rather unfortunate accident with it's 3 color LED but is otherwise fine AFAIK. (It is essentially connected pin for pin in a stack.) I went through the documentation and schematics and modified the variant.h for the xiao_ble option in the firmware as follows:

#ifndef _SEEED_XIAO_NRF52840_SENSE_H_
#define _SEEED_XIAO_NRF52840_SENSE_H_

/** Master clock frequency */
#define VARIANT_MCK (64000000ul)

#define USE_LFXO // Board uses 32khz crystal for LF
// #define USE_LFRC    // Board uses RC for LF

/*----------------------------------------------------------------------------
 *        Headers
 *----------------------------------------------------------------------------*/

#include "WVariant.h"

#ifdef __cplusplus
extern "C" {
#endif // __cplusplus

#define PINS_COUNT (33)
#define NUM_DIGITAL_PINS (33)
#define NUM_ANALOG_INPUTS (8) // A6 is used for battery, A7 is analog reference
#define NUM_ANALOG_OUTPUTS (0)

// LEDs

#define LED_RED 11
#define LED_BLUE 12
#define LED_GREEN 13

#define PIN_LED1 LED_GREEN
#define PIN_LED2 LED_BLUE
#define PIN_LED3 LED_RED

#define PIN_LED PIN_LED1
#define LED_PWR (PINS_COUNT)

#define LED_BUILTIN PIN_LED

#define LED_STATE_ON 1 // State when LED is lit

/*
 * Buttons
 */
#define PIN_BUTTON1 (PINS_COUNT)

// Digital PINs
#define D0 (0ul)
#define D1 (1ul)
#define D2 (2ul)
#define D3 (3ul)
#define D4 (4ul)
#define D5 (5ul)
#define D6 (6ul)
#define D7 (7ul)
#define D8 (8ul)
#define D9 (9ul)
#define D10 (10ul)

/*
 * Analog pins
 */
#define PIN_A0 (0)
#define PIN_A1 (1)
#define PIN_A2 (2)
#define PIN_A3 (3)
#define PIN_A4 (4)
#define PIN_A5 (5)
#define PIN_VBAT (32)
#define VBAT_ENABLE (14)

static const uint8_t A0 = PIN_A0;
static const uint8_t A1 = PIN_A1;
static const uint8_t A2 = PIN_A2;
static const uint8_t A3 = PIN_A3;
static const uint8_t A4 = PIN_A4;
static const uint8_t A5 = PIN_A5;
#define ADC_RESOLUTION 12

// Other pins
#define PIN_NFC1 (30)
#define PIN_NFC2 (31)

/*
 * Serial interfaces
 */
#define PIN_SERIAL1_RX (-1) // (7)
#define PIN_SERIAL1_TX (-1) // (6)

#define PIN_SERIAL2_RX (-1)
#define PIN_SERIAL2_TX (-1)

/*
 * SPI Interfaces
 */
#define SPI_INTERFACES_COUNT 1

#define PIN_SPI_MISO D9
#define PIN_SPI_MOSI D10
#define PIN_SPI_SCK D8

static const uint8_t SS = D3;
static const uint8_t MOSI = PIN_SPI_MOSI;
static const uint8_t MISO = PIN_SPI_MISO;
static const uint8_t SCK = PIN_SPI_SCK;

// supported modules list
#define USE_SX1262

// common pinouts for SX126X modules
#define SX126X_CS D3
#define SX126X_DIO1 D0
#define SX126X_DIO2 D4
#define SX126X_BUSY D1
#define SX126X_RESET D2
#define SX126X_DIO2_AS_RF_SWITCH
#define SX126X_DIO3_TCXO_VOLTAGE 1.8



/*
 * Wire Interfaces
 */
#define WIRE_INTERFACES_COUNT 1 // 2

#define PIN_WIRE_SDA (6)
#define PIN_WIRE_SCL (7)

static const uint8_t SDA = PIN_WIRE_SDA;
static const uint8_t SCL = PIN_WIRE_SCL;

#define PIN_LSM6DS3TR_C_POWER (15)
#define PIN_LSM6DS3TR_C_INT1 (18)

// PDM Interfaces
// ---------------
#define PIN_PDM_PWR (19)
#define PIN_PDM_CLK (20)
#define PIN_PDM_DIN (21)

// QSPI Pins
#define PIN_QSPI_SCK (24)
#define PIN_QSPI_CS (25)
#define PIN_QSPI_IO0 (26)
#define PIN_QSPI_IO1 (27)
#define PIN_QSPI_IO2 (28)
#define PIN_QSPI_IO3 (29)

// On-board QSPI Flash
#define EXTERNAL_FLASH_DEVICES P25Q16H
#define EXTERNAL_FLASH_USE_QSPI

// Battery

#define BAT_READ                                                                                                                 \
    14 // P0_14 = 14  Reads battery voltage from divider on signal board. (PIN_VBAT is reading voltage divider on XIAO and is
       // program pin 32 / or P0.31)
#define BATTERY_SENSE_RESOLUTION_BITS 10
#define CHARGE_LED 23 // P0_17 = 17  D23   YELLOW CHARGE LED
#define HICHG 22      // P0_13 = 13  D22   Charge-select pin for Lipo for 100 mA instead of default 50mA charge

// The battery sense is hooked to pin A0 (5)
#define BATTERY_PIN PIN_VBAT // PIN_A0

// ratio of voltage divider = 3.0 (R17=1M, R18=510k)
#define ADC_MULTIPLIER 3 // 3.0 + a bit for being optimistic

#ifdef __cplusplus
}
#endif

/*----------------------------------------------------------------------------
 *        Arduino objects - C++ only
 *----------------------------------------------------------------------------*/

#endif

Unfortunately it is bootlooping. When I monitor the serial output I get:

��@INFO  | ??:??:?? 4 

//\ E S H T /\ S T / C

DEBUG | ??:??:?? 4 Filesystem files:
DEBUG | ??:??:?? 4  prefs (directory)
DEBUG | ??:??:?? 4    config.proto (166 Bytes)
DEBUG | ??:??:?? 4    channels.proto (57 Bytes)
DEBUG | ??:??:?? 4    db.proto (349 Bytes)
DEBUG | ??:??:?? 4  adafruit (directory)
DEBUG | ??:??:?? 4  bond_prph (directory)
DEBUG | ??:??:?? 4  bond_cntr (directory)
DEBUG | ??:??:?? 4 Power::lipoInit lipo sensor is not ready yet
DEBUG | ??:??:?? 4 Use analog input 32 for battery level
INFO  | ??:??:?? 4 Scan for i2c devices
DEBUG | ??:??:?? 4 Scan for I2C devices on port 1
INFO  | ??:??:?? 4 No I2C devices found
DEBUG | ??:??:?? 4 acc_info = 0
INFO  | ??:??:?? 4 S:B:255,2.5.15
DEBUG | ??:??:?? 4 Reset reason: 0x0
DEBUG | ??:??:?? 4 Set random seed 1782906046
INFO  | ??:??:?? 4 Init NodeDB
INFO  | ??:??:?? 4 Load /prefs/db.proto
INFO  | ??:??:?? 4 Loaded /prefs/db.proto successfully
INFO  | ??:??:?? 4 Loaded saved devicestate version 23, with nodecount: 1
INFO  | ??:??:?? 4 Load /prefs/config.proto
INFO  | ??:??:?? 4 Loaded /prefs/config.proto successfully
INFO  | ??:??:?? 4 Loaded saved config version 23
ERROR | ??:??:?? 4 Could not open / read /prefs/module.proto
INFO  | ??:??:?? 4 Install default ModuleConfig
INFO  | ??:??:?? 4 Load /prefs/channels.proto
INFO  | ??:??:?? 4 Loaded /prefs/channels.proto successfully
INFO  | ??:??:?? 4 Loaded saved channelFile version 23
DEBUG | ??:??:?? 4 cleanupMeshDB purged 0 entries
DEBUG | ??:??:?? 4 Use nodenum 0xc3ee297a 
DEBUG | ??:??:?? 4 Expand short PSK #1
INFO  | ??:??:?? 4 Wanted region 0, using UNSET
DEBUG | ??:??:?? 4 Coerce telemetry to min of 30 minutes on defaults
DEBUG | ??:??:?? 4 Use GPIO33 for button
DEBUG | ??:??:?? 4 Use compiled/slipstreamed tzplaceholder
DEBUG | ??:??:?? 4 Set Timezone to GMT0
DEBUG | ??:??:?? 4 NeighborInfoModule is disabled
DEBUG | ??:??:?? 4 Rescan for I2C keyboard
DEBUG | ??:??:?? 4 Scan for I2C devices on port 1
DEBUG | ??:??:?? 4 Scan address 0x1f
DEBUG | ??:??:?? 4 Scan address 0x55
DEBUG | ??:??:?? 4 Scan address 0x5a
DEBUG | ??:??:?? 4 Scan address 0x5f
INFO  | ??:??:?? 4 External Notification Module Disabled
DEBUG | ??:??:?? 4 SX126xInterface(cs=3, irq=0, rst=2, busy=1)
DEBUG | ??:??:?? 4 SX126X_DIO3_TCXO_VOLTAGE defined, using DIO3 as TCXO reference voltage at 1.800000 V
INFO  | ??:??:?? 4 Start meshradio init
INFO  | ??:??:?? 4 Radio freq=906.875, config.lora.frequency_offset=0.000
INFO  | ??:??:?? 4 Set radio: region=UNSET, name=LongFast, config=0, ch=19, power=30
INFO  | ??:??:?? 4 myRegion->freqStart -> myRegion->freqEnd: 902.000000 -> 928.000000 (26.000000 MHz)
INFO  | ??:??:?? 4 numChannels: 104 x 250.000kHz
INFO  | ??:??:?? 4 channel_num: 20
INFO  | ??:??:?? 4 frequency: 906.875000
INFO  | ??:??:?? 4 Slot time: 77 msec
INFO  | ??:??:?? 4 Set radio: final power level=22
INFO  | ??:??:?? 4 SX126x init result 0
INFO  | ??:??:?? 4 Frequency set to 906.875000
INFO  | ??:??:?? 4 Bandwidth set to 250.000000
INFO  | ??:??:?? 4 Power output set to 22
DEBUG | ??:??:?? 4 Current limit set to 140.000000
DEBUG | ??:??:?? 4 Current limit set result 0
DEBUG | ??:??:?? 4 Set DIO2 as RF switch, result: 0
DEBUG | ??:??:?? 4 SX126X_RXEN not defined, defaulting to RADIOLIB_NC
DEBUG | ??:??:?? 4 SX126X_TXEN not defined, defaulting to RADIOLIB_NC
DEBUG | ??:??:?? 4 Use MCU pin -1 as RXEN and pin -1 as TXEN to control RF switching
INFO  | ??:??:?? 4 Set RX gain to boosted mode; result: 0
INFO  | ??:??:?? 4 SX1262 init success
DEBUG | ??:??:?? 4 LoRA bitrate = 118.394310 bytes / sec
INFO  | ??:??:?? 4 PowerFSM init, USB power=1
DEBUG | ??:??:?? 4 State: BOOT
DEBUG | ??:??:?? 5 [Power] Battery: usbPower=0, isCharging=0, batMv=4144, batPct=96
INFO  | ??:??:?? 5 [RangeTest] Range Test Module - Disabled
INFO  | ??:??:?? 8 [PowerFSM] Loss of power in Powered
INFO  | ??:??:?? 8 [PowerFSM] Loss of power in Powered
DEBUG | ??:??:?? 8 [PowerFSM] Init NRF52 Bluetooth
INFO  | ??:??:?? 8 [PowerFSM] Init the Bluefr

I am going to keep poking around, but I was wondering if anyone sees something I am not.