This project contains a box to hide the nodeMCU esp8266 together with a 0.96" oled display. The box is then connected to an external usb power supply that is on the nodeMCU board.

First, the nodeMCU board is slid into the bottom box on four sticks, attached with a melt gun, and then the display is attached to the lid using a melt gun. The lid is slid onto the box. The box can be attached anywhere using double-sided adhesive tape. The lid can be removed from the box at any time.

If you want to use this case as it is in the photo to display PV data from a Solax inverter, you can download the source code below. You will need Home assistant and the ESPHome add-on installed for this. You can also use the icons, which are also downloadable.

esphome: name: photovoltaics friendly_name: photovoltaics esp8266: board: nodemcuv2 # Enable logging logger: # Enable Home Assistant API api: encryption: key: "yourkey" ota: platform: esphome password: "yourpassword" # num_attempts: 3 # safe_mode: no wifi: ssid: !secret wifi_ssid password: !secret wifi_password # Enable fallback hotspot (captive portal) in case wifi connection fails ap: ssid: "Photovoltaics Fallback Hotspot" password: "password" #switch: # - platform: gpio # pin: D4 #interni led # inverted: True # name: "NodeMCU internal LED" # id: internal_led time: - platform: homeassistant id: homeassistant_time timezone: Europe/Prague image: # The folder for images is (create) on HA in \config\esphome\_icons - file: "_icons/pv.png" id: imgPV - file: "_icons/bat.png" id: imgBat - file: "_icons/grid.png" id: imgGrid - file: "_icons/house.png" id: imgDum sensor: - platform: homeassistant id: fve_production entity_id: sensor.solax_pv_power_total internal: true - platform: homeassistant id: fve_consumption entity_id: sensor.solax_house_load internal: true - platform: homeassistant id: fve_battery entity_id: sensor.solax_battery_power_charge internal: true - platform: homeassistant id: fve_battery_soc entity_id: sensor.solax_battery_capacity internal: true - platform: homeassistant id: fve_grid entity_id: sensor.solax_grid_import internal: true font: - file: 'arial.ttf' id: font1 size: 13 - file: 'arial.ttf' id: font2 size: 12 i2c: sda: D2 scl: D1 scan: false display: - platform: ssd1306_i2c model: SSD1306_128X64 address: 0x3C id: my_display lambda: |- it.image(0, 2, id(imgPV)); if (id(fve_production).state <= 999) { it.printf(15, 0, id(font1), TextAlign::TOP_LEFT, "%.0f W", id(fve_production).state); } else { it.printf(15, 0, id(font1), TextAlign::TOP_LEFT, "%.2f kW", id(fve_production).state/1000); } it.image(0, 19, id(imgDum)); if (id(fve_consumption).state <= 999) { it.printf(15, 33, id(font1), TextAlign::BOTTOM_LEFT, "%.0f W", id(fve_consumption).state); } else { it.printf(15, 33, id(font1), TextAlign::BOTTOM_LEFT, "%.2f kW", id(fve_consumption).state/1000); } it.image(0, 35, id(imgGrid)); if (id(fve_grid).state <= 999) { it.printf(15, 49, id(font1), TextAlign::BOTTOM_LEFT, "%.0f W", id(fve_grid).state); } else { it.printf(15, 49, id(font1), TextAlign::BOTTOM_LEFT, "%.2f kW", id(fve_grid).state/1000); } it.strftime(0, 51, id(font1), " %d.%m.%Y %H:%M", id(homeassistant_time).now()); it.image(116, 2, id(imgBat)); it.printf(115, 0, id(font1), TextAlign::TOP_RIGHT, "%.0f%%", id(fve_battery_soc).state); it.image(116, 19, id(imgBat)); if ((id(fve_consumption).state) >= 0) { if ((id(fve_consumption).state) <= 999) { it.printf(115, 19, id(font2), TextAlign::TOP_RIGHT, "%.0f W", id(fve_battery).state); } else { it.printf(115, 19, id(font2), TextAlign::TOP_RIGHT, "%.2fkW", id(fve_battery).state/1000); } } else { if ((id(fve_consumption).state) >= -999) { it.printf(115, 19, id(font2), TextAlign::TOP_RIGHT, "-%.0f W", id(fve_battery).state); } else { it.printf(115, 19, id(font2), TextAlign::TOP_RIGHT, "-%.2fkW", id(fve_battery).state/1000); } } captive_portal: