Your kit will contain two pairs of either through-hole or SMD resistors. The keyboard exposes an I2C bus which is most commonly used to communicate with an OLED. To work properly, the I2C bus requires the installation of these pull-up resistors.
Although this step is optional if you are not using I2C devices like OLEDs, installing them anyways won't hurt and prevents you from losing them in case you need them in the future.
Spares: You might have some spares left over after this step. That's expected: you'll be able to make some mistakes or lose a few without it being stressful ;)
Sizes: The resistors in your kit may differ slightly from the ones shown here. The kits are compatible with various sizes of axial and SMD resistors, and their exact value isn't important when used for keyboards. They're typically 4.7K or 10K ohm, but should be in the range of 2K to 10K. The more you know!
Installing through-hole resistors
If you’re using SMD resistors, please skip to the next section on this page.
Check which side is recommended for your kit by looking for a white resistor outline next to the resistor pads. They’ll be marked R1 and R2. On most kits this will be the top side. Only the Aurora Helix will have an R3 too.
Aurora Helix: The Aurora Helix is the only keyboard in the series that has an R3. Only install this if you're using a wired controller and QMK. It's used for side detection for the Helix, which is done differently in ZMK. The more you know!
On most kits they will physically fit on the other side too, but we don't recommend it. If you do go for this approach, make sure to double-check the clearance - especially when using a JST jack for a wireless controller.
Similar to the diodes, bend the resistors and insert them into the PCB. Unlike diodes, their orientation does not matter.
Bend the legs a little after inserting them so they’ll stay in place.
Solder them from either the top or the bottom.
Cut the legs off flush using a flush cutter. You won’t need to save these legs for a later step.
Remember, use one hand to hold the leg and the other to cut it - you don't want loose legs flying everywhere.
Installing SMD resistors
If you just installed through-hole resistors, please continue to the next page.
Check where they need to be installed for your kit by looking for a white resistor outline next to the resistor pads. They’ll be marked R1 and R2. On most kits this will be the top side. Only the Aurora Helix will have an R3 too.
Aurora Helix: The Aurora Helix is the only keyboard in the series that has an R3. Only install this if you're using a wired controller and QMK. It's used for side detection for the Helix, which is done differently in ZMK. The more you know!
Similar to the diodes, solder some tin on one of the two rectangular pads on the resistor footprint. Leave the pads with holes alone - you won’t need them for SMD resistors.
Grab a resistor using tweezers in one hand, and use your soldering iron with your other hand. Move the resistor next to a pad you just soldered, and heat up the solder until it melts.
Then, move the resistor in place, touching both the resistor terminal and the pad with your soldering iron until you notice a solder joint form — this usually only takes a second or two.
Remove the soldering iron, wait until the solder joint solidifies, and release the tweezers.
Unlike diodes, their orientation does not matter.
Solder the other joint. This one should go a lot easier as the first one is already holding the resistor in place, so you don't need to use tweezers anymore.
Repeat this process for the other resistor.