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iothings:proiecte:2021:retroweatherstation [2022/01/24 03:24] florin.dragulin |
iothings:proiecte:2021:retroweatherstation [2022/01/27 22:10] (current) florin.dragulin |
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| {{:iothings:proiecte:2021:samsung_sve_11ms21.png?400| Samsung SVE 11MS21}} | {{:iothings:proiecte:2021:samsung_sve_11ms21.png?400| Samsung SVE 11MS21}} | ||
| - | Due to limited amount on the ESP32 bord, to drive those 20 pins I used a special IC which can handle higher voltages, Microchip HV5812, a serial 20-bit shift register with VDD = 4.5-5.5V for logic circuits and VPP = 20 – 80V for high voltage. | + | Due to limited amount on the ESP32 board, to drive those 20 pins I used a special IC which can handle higher voltages, Microchip HV5812, a serial 20-bit shift register with VDD = 4.5-5.5V for logic circuits and VPP = 20 – 80V for high voltage. |
| Data-In, CLK and Strobe will be driven by ESP32. To obtain 30-32V from my 9V DC power I used a switch mode power supply (SMPS) with MT3608 IC to have a higher efficiency. | Data-In, CLK and Strobe will be driven by ESP32. To obtain 30-32V from my 9V DC power I used a switch mode power supply (SMPS) with MT3608 IC to have a higher efficiency. | ||
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| *2. Slave station | *2. Slave station | ||
| - | It will be placed outside to sample temperature, humidity and pressure. To have communication with core station, I used the same microcontroller, ESP32 dev board. External parameters are capture using BMP280 with I2C interface at 3.3V logic level. | + | It will be placed outside to sample temperature, humidity and pressure. To have communication with core station, I used the same microcontroller, ESP32 dev board. External parameters are capture using BMP280 with I2C interface at 3.3V logic level |
| Outside outlets are not every time easy to get so a cordless station is needed. For that cheapest and fastest solution is to use a Li-Ion connected to 1W solar panel. Li-Ion cells have a maximum voltage at 4.2 – 4.3V when are at 100% state of charge (SOC), keep a steady voltage between 80% and 20% SOC, at 3.7V and then drop almost linearly to 2.3V. | Outside outlets are not every time easy to get so a cordless station is needed. For that cheapest and fastest solution is to use a Li-Ion connected to 1W solar panel. Li-Ion cells have a maximum voltage at 4.2 – 4.3V when are at 100% state of charge (SOC), keep a steady voltage between 80% and 20% SOC, at 3.7V and then drop almost linearly to 2.3V. | ||
