ErgoDox Wireless FAQ
How long is the battery life on a 400mAh battery?
Without solar charging and without a dongle, the left half (central half) would last around a month and the right half (peripheral half) would last around 9 months. Without solar charging and with a dongle, both halves would act as a "peripheral" half and the battery would last around 9 months. Please read about how a dongle improves battery life for a split keyboard.
With solar charging and a dongle, the battery life would be dependent on the amount of light available. Natural light from the sun works much better than artificial lighting as the former is brighter by a significant margin. The keyboard would automatically charge when there is enough light and fall back to using the battery otherwise. Whether solar charging merely improves battery life or is sufficient to not need charging depends on a number of factors. It's mostly affected by the brightness and quantity of light along with how much the keyboard is used.
Without a dongle, solar charging will not improve the battery life for the left/central half. The right/peripheral half on the other hand would still benefit.
Are there wireless signal issues with the aluminum case (Pro) compared with the layered case (Lite)?
We haven't seen any significant difference in the signal quality between the aluminum case and the layered case. In particular, the aluminum case has an acrylic bottom layer to ensure that the signal can propagate.
From our testing, the number of disconnects due to interference is about the same with the two case options. Our logs recorded a few disconnects each week on average. These disconnects often don't impact usage as some may happen when the keyboard is not in use; the connection is automatically reestablished anyways.
Our hardware supports Bluetooth Long Range PHY, which can be enabled to further improve the signal reliability in harsh environments. It comes at the cost of a slight increase in power consumption. It's not enabled by default as it hasn't been necessary.
How is the keyboard latency?
ZMK currently supports Bluetooth connection interval as low as 7.5ms, which means the average Bluetooth latency can be as low as 3.75ms.
- When using the dongle directly (or connected to the central half via USB C), a millisecond or two should be added to account for USB latency, key press debouncing, and general firmware logic processing.
- A device connected wireless to the central (whether it be an external dongle or one of the keyboard halves) will experience latency that is approximately twice the connection interval as data has to travel wirelessly twice.
It's difficult to quantify the latency objectively because there are so many factors that influence it. Changing the connection interval can decrease latency at the cost of using more power. Changing the key debouncing algorithm can also decrease latency at the cost of making the matrix scanning a bit less resilient.
The Nordic microprocessors that we use supports a Bluetooth extension called Low Latency Packet Mode, which allows the connection interval to be as low as 1ms. Combined with 1ms of USB polling and 1ms of processing time, it's theoretically possible to achieve total latency around 3ms. While this is something that can be added via a firmware upgrade, please note that we have no concrete plans of implementing Low Latency Packet Mode at this time. This largely is because our users have not had issues with the current connection interval and latency.
Can I use the keyboard with multiple devices?
Yes. If using a dongle, one computer can use the dongle as a USB keyboard and additional devices can connect to the dongle wirelessly.
If not using a dongle, multiple devices can connect to the central half wirelessly. The central half can also be plugged in via USB and used directly as a USB keyboard.
Can I use the keyboard in a wired manner?
If using a dongle, only wireless is supported for the connection between the keyboard halves and the dongle. In such case, the USB connection for the keyboard halves is solely for the purpose of charging. The dongle acts as a USB keyboard and can be used on devices without Bluetooth.
If using one of the keyboard halves (such as the left half) is used as the central in place of an external dongle, that half can be used directly over USB as a USB keyboard. However it will continue to communicate with the other half wirelessly.