Efficient energy management of simple agricultural IoT devices
Budget: $30 – $250 USD
I'm developing a two devices system for monitoring ambient conditions, each one controlled by an ESP32. The measurement device uses a BME280 sensor and a LoRa module to transmit the data to the second one, the Gateway, tha receives the LoRa msg and publishes the info into a MQTT port using WiFi.
The first device consumes around 5 mA in deep sleep and 65mA during measurements; the second one consumes 10mA during sleepMode and 160 during LoRa + WiFi tasks (45 seconds). The Gateway rests under lightSleep and wakes up when new LoRa messages are incoming. The cycle repeats every 30 minutes. So the daily consume of the measurement device is 640 mW/day and the GW consumes 900 mW/day.
For the electric supply of the measurement device i'm using a chinese 500 mA, 5v solar panel, a replica of the Samsung 18650 battery with 2500mAh capacity and a LDO mode TLV757P (3.3V, 1A). For energy management I'm using a LM2596 regulator to low the voltage at 5 Volts to a TP4056 battery charger. Then, the LDO supplies constant 3.3 volts to the ESP32, LoRa and sensor.
For the gateway, I use a 12V, 10W solar panel, with a PMW voltage regulator, a 12V, 7Ah lead-acid rechargeable battery and a LM2596 regulator (to get 5V). The gateway PCB regulates the voltage to 3.3v with the TL757P LDO. The LM2596 regulator feeds a wireless 4G router.
Recently I've noticed that I should add a power path with a Schottky diode and a MOSFET after the charger so the system can manage the solar panel energy more efficiently. And I think I have too many filter capacitors before every chip mentioned.
I need a review of the schematics, verify if a power path solution is a better way than the present one, and advise some energy efficiency improvements of the PCB so it can run outdoors for several months. I can delivery the datasheets of every chip used, the schematics and the PCB board layout if needed.
The results has to be presented in a video meeting (english or spanish) and I pay 60 USD. No deliverable documents are required.
The first device consumes around 5 mA in deep sleep and 65mA during measurements; the second one consumes 10mA during sleepMode and 160 during LoRa + WiFi tasks (45 seconds). The Gateway rests under lightSleep and wakes up when new LoRa messages are incoming. The cycle repeats every 30 minutes. So the daily consume of the measurement device is 640 mW/day and the GW consumes 900 mW/day.
For the electric supply of the measurement device i'm using a chinese 500 mA, 5v solar panel, a replica of the Samsung 18650 battery with 2500mAh capacity and a LDO mode TLV757P (3.3V, 1A). For energy management I'm using a LM2596 regulator to low the voltage at 5 Volts to a TP4056 battery charger. Then, the LDO supplies constant 3.3 volts to the ESP32, LoRa and sensor.
For the gateway, I use a 12V, 10W solar panel, with a PMW voltage regulator, a 12V, 7Ah lead-acid rechargeable battery and a LM2596 regulator (to get 5V). The gateway PCB regulates the voltage to 3.3v with the TL757P LDO. The LM2596 regulator feeds a wireless 4G router.
Recently I've noticed that I should add a power path with a Schottky diode and a MOSFET after the charger so the system can manage the solar panel energy more efficiently. And I think I have too many filter capacitors before every chip mentioned.
I need a review of the schematics, verify if a power path solution is a better way than the present one, and advise some energy efficiency improvements of the PCB so it can run outdoors for several months. I can delivery the datasheets of every chip used, the schematics and the PCB board layout if needed.
The results has to be presented in a video meeting (english or spanish) and I pay 60 USD. No deliverable documents are required.
Related categories:
Electronics
Electrical Engineering
Energy
Circuit Design
Internet of Things (IoT)