# Getting RTC driver working on i2c-3 (HyperPixel)

**URL:** <https://forums.pimoroni.com/t/getting-rtc-driver-working-on-i2c-3-hyperpixel/11982>\
**Category:** Support\
**Created:** [October 21, 2019, 11:15pm UTC](https://forums.pimoroni.com/t/getting-rtc-driver-working-on-i2c-3-hyperpixel/11982 "2019-10-21T23:15:06Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![GregOMC](https://avatars.discourse-cdn.com/v4/letter/g/c5a1d2/32.png) [@GregOMC](https://forums.pimoroni.com/u/GregOMC)\
**Post date:** [October 21, 2019, 11:15pm UTC](https://forums.pimoroni.com/t/getting-rtc-driver-working-on-i2c-3-hyperpixel/11982/1 "2019-10-21T23:15:07Z")

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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:

> [@Pi3 B+ , HyperPixel 4" , DS3231 timer , Debian](https://forums.pimoroni.com/t/pi3-b-hyperpixel-4-ds3231-timer-debian/10492/5):
>
> Thanks for your reply… So I did some experimenting and turns out, Clock works great when config.txt has remarked out. #Turn on HyperPixel lcd #dtoverlay=hyperpixel4:rotate and while LCD AND Clock connected, LCD works fine even with this enabled. This is to enable the DS3231 RTC clock dtoverlay=i2c-rtc,ds3231 So, I have different configuration for a different purpose. To swap LCD and HDMI depending if HDMI is detected. Basicly , if hdmi is detected, then it renames and uses the HDMI confi…

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](https://www.raspberrypi.org/forums/viewtopic.php?t=213312)  
Still no luck.

Any help appreciated!

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<div class="post-metadata">

**Author:** ![tvoverbeek](https://avatars.discourse-cdn.com/v4/letter/t/f08c70/32.png) [@tvoverbeek](https://forums.pimoroni.com/u/tvoverbeek)\
**Post date:** [March 1, 2020, 1:53pm UTC](https://forums.pimoroni.com/t/getting-rtc-driver-working-on-i2c-3-hyperpixel/11982/2 "2020-03-01T13:53:06Z")

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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)
```