Plant Care¶

Plant Monitoring System

1. Plant Care ESP8266¶

1.1. Powering:¶

Solar power
Small space

Battery charging: Power Cell - LiPo Charger/Booster ¶

MCP73831 Single Cell LiPo charger met 500mA
TPS61200 Boost Converter
Selecteerbaar output voltage 3.3 or 5V
5V @ 600mA max
3.3V @ 200mA max
JST connector voor LiPo batterij
micro-USB connector voor charge power
Temp. beveiliging

Power Supply: 4 x 5V - 30mA Solar Panel 53x30 ¶

53x30 mm
Typical voltage: 5V
Typical current: 30mA

Battery: LiPo accupack 3.7 V 600 mAh ¶

Belgium Solar Hours in Januari = 1.9h/day → Energy = 0.95Wh/day → 12mA continuous current (3.3V)

1.2. Microcontroller:¶

Low Power Consumption
WiFi and TCP/IP stack available

Model¶

**Wemos D1 mini** / ESP 12e (ESP8266)

The ESP8266 is a low-cost Wi-Fi chip with full TCP/IP stack and MCU (microcontroller unit) capability produced by Shanghai-based Chinese manufacturer, Espressif Systems. [ESP8266 Overview]

802.11 b / g / n
Wi-Fi Direct (P2P), soft-AP
Built-in TCP / IP protocol stack
Built-in TR switch, balun, LNA, power amplifier and matching network
Built-in PLL, voltage regulator and power management components
802.11b mode + 19.5dBm output power
Built-in temperature sensor
Support antenna diversity
off leakage current is less than 10uA
Built-in low-power 32-bit CPU: can double as an application processor
SDIO 2.0, SPI, UART
STBC, 1×1 MIMO, 2×1 MIMO
A-MPDU, A-MSDU aggregation and the 0.4 Within wake
2ms, connect and transfer data packets
standby power consumption of less than 1.0mW (DTIM3)

Power Consumption¶

Parameters	Typical	Unit
Tx 802.11b, CCK 11Mbps, P OUT=+17dBm	170	mA
Tx 802.11g, OFDM 54Mbps, P OUT =+15dBm	140	mA
Tx 802.11n, MCS7, P OUT =+13dBm	120	mA
Rx 802.11b, 1024 bytes packet length, -80dBm	50	mA
Rx 802.11g, 1024 bytes packet length, -70dBm	56	mA
Rx 802.11n, 1024 bytes packet length, -65dBm	56	mA
Modem-Sleep ❶	15	mA
Light-Sleep ❷	0,9	mA
Deep-Sleep ❸	10	uA

❶ Modem-Sleep requires the CPU to be working, as in PWM or I2S applications. According to 802.11 standards (like U-APSD), it saves power to shut down the Wi-Fi Modem circuit while maintaining a Wi-Fi connection with no data transmission. E.g. in DTIM3, to maintain a sleep 300mswake 3ms cycle to receive AP’s Beacon packages, the current is about 15mA.

❷ During Light-Sleep, the CPU may be suspended in applications like Wi-Fi switch. Without data transmission, the Wi-Fi Modem circuit can be turned off and CPU suspended to save power according to the 802.11 standard (U-APSD). E.g. in DTIM3, to maintain a sleep 300ms-wake 3ms cycle to receive AP’s Beacon packages, the current is about 0.9mA.

❸ Deep-Sleep does not require Wi-Fi connection to be maintained. For application with long time lags between data transmission, e.g. a temperature sensor that checks the temperature every 100s, sleep 300s and waking up to connect to the AP (taking about 0.3~1s), the overall average current is less than 1mA.

1.3. Communication:¶

I²C: Internal Sensor - ESP¶

It is typically used for attaching lower-speed peripheral ICs to processors and microcontrollers in short-distance, intra-board communication. (I²C)

IEEE 802.11 b/g/n Wi-Fi - MQTT: Data publishing¶

It is useful for connections with remote locations where a small code footprint is required and/or network bandwidth is at a premium. (MQTT)

Sensors:¶

I²C¶

Analog¶

Bodemvochtigheidssensor
[STRIKEOUT:Capacitieve Bodem Sensor]

Costum¶

Temp. en vochtigheid - DHT22

1.4. Data analysis / Algorithm¶

3. Plant Care Monitorings Portal¶

4. Intern Protocol¶

Sensor communication¶

MQTT Topic: sunflower_project/<ID>/Sensor/<Sensor_Metric>/<Unix_Timestamp>

ID: (e.g.)``1437B2``
System_Metric: (e.g.) sensor_light
Unix_Timestamp: (e.g.) 1510255785

MQTT Message: value

System info¶

MQTT Topic: sunflower_project/<ID>/System/<System_Metric>/<Unix_Timestamp>

ID: (e.g.)``1437B2``
System_Metric: (e.g.) system_battery
Unix_Timestamp: (e.g.) 1510255785