As Davis consoles and Envoys are fed by a 5 volt 300 mA power supply it is obvious that this can be insufficient. With the black ribbon NANOs situation is OK, as the 300 mA border is mostly not reached and NANOs onboard buffer capacitors can handle short voltage drop spikes fine. With the red ribbon NANOs the situation is handled by reducing the TX power emission via software by setting specific radio parameters of the VoCore2 SOC. We do that to allow you to operate the NANO as a true plugin without the need to use or purchase additional items.
As we are on the edge in regard to power consumption there can be situations where your power supply might be a bit under the official specs and the NANO might draw a bit more energy than our test samples. If those variances meet, voltage of the power supply might drop below a critical level and you might see spontaneous reboots of your NANO. If you are facing this you can apply two cures:
1) You can add batteries. Having batteries these will step in on the power demand spikes and will help the power supply to maintain the necessary voltage level. Think of the batteries as a power reserve, which is just used when the power supply struggles. Even if you don't face reboot situations, having these batteries is recommended. Batteries used in addition to the power supply are expected to last very long as they only step in on the rare occasions when needed.
2) You can get a more beefy power supply and all worries are gone forever. I have heard that Davis itself now sells 1A versions of the console power supply, so you might ask your dealer when you are keen to a Davis original replacement. How much current your power supply can deliver is written on the specs sticker at the bottom of the supply. When you are willing to get a third party one for less than 10 bucks from amazon, ebay, aliexpress or alike search for 5V 1A models with a barrel plug with 3.5mm outer diameter size and inner hole diameter of 1.35mm. Plus pole must be on the inner hole. Examples of fitting models:
- Amazon: https://www.amazon.com/atolla-Standard- ... y0_hl_23_6
- ebay: https://www.ebay.com/itm/Power-Supply-A ... 2505064439
- aliexpress: https://www.aliexpress.com/item/AC-100- ... 7db4M36NzF
We added a "Power Boost" option for the red ribbon NANOs to make full use of the WiFi transmission power of these models in case you are operating on batteries or (better) with a 1A power supply. This option can be selected on the "network" tab of affected models. Please don't use this if your power supply does not give the needed juice, it will be stuck in reboots for sure. To give you a chance to disable this feature the full WiFi emission power is enabled after waiting 10 minutes past starting the NANO.
Some of the Davis 300 mA power supplies are told to struggle on initial power-on of the NANO module. This is because the NANOs do have buffer capacitors (2000 uF) on board which draw a lot of current when filling up for the first time. When the NANO LED does not show any sign of life within 10 seconds after power-on, please disconnect power and quickly connect power again. By this the capacitors still have a certain voltage level, which makes starting up more easy for the power supply. Reboots later on are no problem. Only a few Davis power supplies behave like this, so chance is good you never need to power cycle a second time.