Getting RTC driver working on i2c-3 (HyperPixel)

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1

I’ve had some success with using the HyperPixel 4.0 with the PiJuice HAT (and the PiJuice Zero pHAT). However I haven’t been able to get the RTC (ds1339) working however, since the dtoverlays don’t expect it on i2c-3.

The symbolic link that is suggested doesn’t seem to work for this, and I’ve had no luck with dtoverlays (i2c-gpio-rtc, or even making my own with target=<&i2c3>; dtbo).

I’ve followed i2c-rtc-gpio the instructions at:

Sadly, no joy - i2cdetect -y 3 yields the address 0x68, but no UU (kernal driver not added).

I’ve also tried compiling my own dtbo overlay with target i2c_arm replaced with i2c3 (as opposed to i2c_vc per this link)
https://www.raspberrypi.org/forums/viewtopic.php?t=213312
Still no luck.

Any help appreciated!

2

Since with the HyperPixel you are using the software i2c-bus (i2c-gpio) look at the overlay
i2c-rtc-gpio.
From the README in /boot/overlays:

Name:   i2c-rtc-gpio
Info:   Adds support for a number of I2C Real Time Clock devices
        using the software i2c controller
Load:   dtoverlay=i2c-rtc-gpio,<param>=<val>
Params: abx80x                  Select one of the ABx80x family:
                                  AB0801, AB0803, AB0804, AB0805,
                                  AB1801, AB1803, AB1804, AB1805

    ds1307                  Select the DS1307 device

    ds1339                  Select the DS1339 device

    ds3231                  Select the DS3231 device

    m41t62                  Select the M41T62 device

    mcp7940x                Select the MCP7940x device

    mcp7941x                Select the MCP7941x device

    pcf2127                 Select the PCF2127 device

    pcf2129                 Select the PCF2129 device

    pcf8523                 Select the PCF8523 device

    pcf8563                 Select the PCF8563 device

    rv3028                  Select the Micro Crystal RV3028 device

    addr                    Sets the address for the RTC. Note that the
                            device must be configured to use the specified
                            address.

    trickle-diode-type      Diode type for trickle charge - "standard" or
                            "schottky" (ABx80x only)

    trickle-resistor-ohms   Resistor value for trickle charge (DS1339,
                            ABx80x, RV3028)

    wakeup-source           Specify that the RTC can be used as a wakeup
                            source

    backup-switchover-mode  Backup power supply switch mode. Must be 0 for
                            off or 1 for Vdd < VBackup (RV3028 only)

    i2c_gpio_sda            GPIO used for I2C data (default "23")

    i2c_gpio_scl            GPIO used for I2C clock (default "24")

    i2c_gpio_delay_us       Clock delay in microseconds
                            (default "2" = ~100kHz)