ESP8266 Community Forum

- Wed Jan 11, 2023 6:30 am #95775 I normally use a 220uF 6.3V reservoir. Bigger is not necessarily better here. One has to take into account ESR (equivalent series resistance) and frequency characteristics.

The purpose of the reservoir is to provide a low impedance source of current for handling pulse changes. The main power source and regulator should be able to respond to slower changes of the order of a few 10s of uS. This can be degraded by any lead inductance between the regulator and the module and is why the capacitor is best positioned close to the module.

I normally use tantulum capacitors for this. They are a bit more expensive than aluminium but are smaller, have much lower esr and this is maintained at high frequencies. One has to be a little careful to ensure they cannot be reverse connected as that can rapidly destroy them but that is not normally a problem in a simple reservoir application.

- Tue May 30, 2023 12:46 am #96489 Hi there! Welcome to the site! I understand that you're using a 8226 as a web server to display temperature and humidity readings from a DHT11 module in an outbuilding. It seems like you're facing an issue where you have to manually press the reset button after a power outage.

To address this problem, you can consider a few solutions:

Automatic Reset: One option is to automate the reset process using additional hardware or components such as a timer or a microcontroller. These can be programmed to detect power outages and trigger a reset sequence for your 8226 device.

Power Backup: Another approach is to provide a power backup solution for your 8226 device. This can be achieved using uninterruptible power supply (UPS) systems or battery backup solutions. These devices can provide temporary power during outages, allowing your web server to continue running without requiring a manual reset.

Remote Control: You could explore the possibility of remote control options for your 8226 device. This could involve using a remote power switch or a smart power outlet that can be controlled remotely. With this setup, you can remotely power cycle your web server when needed, eliminating the need for manual intervention.

Consider these options and choose the one that best suits your requirements. If you need more specific guidance or further assistance, feel free to provide additional details, and I'll be happy to help you further.