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Vikhyat Goyal
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Add driver for grove soil moisture sensor
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‎extra/Grove_Capacitive_Soil_Moisture_Sensor.ipynb‎

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{
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"cells": [
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{
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"cell_type": "markdown",
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"metadata": {},
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"source": [
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"# Grove Soil Moisture Sensor\n",
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"\n",
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"This example shows how to use the Grove Corrosion-resistant Capacitive Soil Moisture Sensor.\n",
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"The Grove Soil Moisture Sensor produces an analog signal, and requires an ADC. \n",
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"\n",
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"A Pynq Grove Adapter, or Pynq Shield and a Grove I2C ADC are required for this example. \n",
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"\n",
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"In the example, the ADC is initialized, a test read is done, and then the sensor is set to log a reading every 100 milliseconds. "
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]
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},
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{
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"cell_type": "markdown",
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"metadata": {},
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"source": [
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"## Overview\n",
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"\n",
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"The Grove - Capacitive Moisture Sensor (Corrosion Resistant) is a soil moisture sensor based on capacitance changes. Compared with resistive sensors, capacitive sensors do not require direct exposure of the metal electrodes, which can significantly reduce the erosion of the electrodes. Hence, we call it Corrosion Resistant.\n",
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"\n",
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"It is important to note that this sensor can only qualitatively test the humidity of the soil and cannot measure quantitatively. Which means when the humidity of the soil rises, the value of the output decreases; conversely, when the humidity decreases, the output value becomes higher.\n",
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"\n"
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]
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},
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{
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"cell_type": "markdown",
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"metadata": {},
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"source": [
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"## Helpful Links\n",
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"\n",
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"[Sensor webpage](https://wiki.seeedstudio.com/Grove-Capacitive_Moisture_Sensor-Corrosion-Resistant/)\n",
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"\n",
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"[PMOD to Grove adapter webpage](https://store.digilentinc.com/pynq-grove-system-add-on-board/)"
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]
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},
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{
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"cell_type": "markdown",
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"metadata": {},
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"source": [
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"## Using the Sensor"
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]
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},
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{
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"cell_type": "markdown",
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"metadata": {},
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"source": [
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"## Attention\n",
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"\n",
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"The part of the sensor inserted into the soil cannot exceed the highest position line (the white line).\n",
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"\n"
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]
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},
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{
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"cell_type": "markdown",
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"metadata": {},
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"source": [
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"### For this example, the PYNQ PMOD to Grove adapter is connected to PMODA, and the grove ADC is connected to group 'G4' on the adapter.\n"
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]
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},
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{
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"cell_type": "markdown",
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"metadata": {},
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"source": [
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"### 1. Load the base Overlay"
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]
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},
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{
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"cell_type": "code",
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"execution_count": 9,
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"metadata": {},
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"outputs": [],
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"source": [
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"from pynq.overlays.base import BaseOverlay\n",
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"base = BaseOverlay(\"base.bit\")"
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]
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},
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{
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"cell_type": "markdown",
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"metadata": {},
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"source": [
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"### 2. ADC read from sensor"
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]
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},
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{
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"cell_type": "code",
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"execution_count": 50,
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"metadata": {
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"scrolled": true
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},
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"outputs": [
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{
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"name": "stdout",
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"output_type": "stream",
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"text": [
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"2.029834 V\n"
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]
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}
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],
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"source": [
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"from pynq.lib.pmod import Grove_ADC\n",
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"from pynq.lib.pmod import PMOD_GROVE_G4 \n",
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"\n",
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"grove_adc = Grove_ADC(base.PMODA,PMOD_GROVE_G4)\n",
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"print(\"{} V\".format(round(grove_adc.read(),6)))"
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]
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},
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{
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"cell_type": "markdown",
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"metadata": {},
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"source": [
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"### 3. Scale Voltage value for ease of use"
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]
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},
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{
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"cell_type": "code",
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"execution_count": 51,
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"metadata": {
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"scrolled": true
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},
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"outputs": [
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{
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"name": "stdout",
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"output_type": "stream",
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"text": [
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"686\n"
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]
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}
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],
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"source": [
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"# We assume output is 1-2.5V\n",
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"# We scale it to 0-1000 for \"ease\" of use\n",
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"\n",
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"v = round(grove_adc.read(),6) - 1\n",
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"if v<0:\n",
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" print(\"Sensor not connected\")\n",
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"else:\n",
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" print(int(v* 666.666))"
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]
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},
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{
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"cell_type": "markdown",
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"metadata": {},
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"source": [
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"### 4. Starting logging once every 100 milliseconds and print recorded values"
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]
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},
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{
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"cell_type": "code",
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"execution_count": 75,
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"metadata": {},
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"outputs": [],
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"source": [
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"grove_adc.set_log_interval_ms(100)\n",
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"grove_adc.start_log()"
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]
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},
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{
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"cell_type": "code",
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"execution_count": 76,
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"metadata": {},
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"outputs": [
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{
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"name": "stdout",
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"output_type": "stream",
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"text": [
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"[0.0938, 0.0938, 0.0938, 0.0938, 0.0938, 0.0938, 0.0938, 0.0938, 0.0938, 0.0938, 0.0938, 0.0938, 0.0938, 0.0938, 0.0938, 0.0938, 0.0938, 0.0938, 0.0938, 0.0938, 0.0938, 0.0938, 0.0938, 0.0938]\n"
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]
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}
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],
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"source": [
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"log = grove_adc.get_log()\n",
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"print(log)\n",
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"\n"
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]
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},
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{
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"cell_type": "markdown",
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"metadata": {},
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"source": [
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"### 5. Get the average voltage value and scale it\n"
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]
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},
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{
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"cell_type": "code",
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"execution_count": 77,
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"metadata": {},
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"outputs": [
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{
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"name": "stdout",
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"output_type": "stream",
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"text": [
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"0.09379999999999994\n",
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"-604\n"
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]
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}
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],
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"source": [
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"av = sum(log)/len(log)\n",
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"print(av)\n",
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"final = int((round(av,6) - 1)*666.666)\n",
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"print(final)"
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]
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},
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{
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"cell_type": "markdown",
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"metadata": {},
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"source": [
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"### 6. Final humidity output"
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]
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},
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{
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"cell_type": "code",
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"execution_count": 78,
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"metadata": {},
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"outputs": [
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{
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"name": "stdout",
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"output_type": "stream",
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"text": [
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"Sensor is not connected.\n"
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]
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}
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],
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"source": [
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"if (final >0 and final <300):\n",
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" print (\"Soil Humidity is high.\")\n",
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"elif (final >300 and final <600):\n",
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" print (\"Soil Humidity is normal.\")\n",
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"elif final >600:\n",
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" print (\"Soil Humidity is low. Watering is required.\")\n",
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"else:\n",
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" print (\"Sensor is not connected.\")"
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]
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},
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{
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"cell_type": "code",
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"execution_count": null,
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"metadata": {},
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"outputs": [],
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"source": []
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}
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],
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"metadata": {
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"kernelspec": {
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"display_name": "Python 3",
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"language": "python",
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"name": "python3"
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},
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"language_info": {
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"codemirror_mode": {
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"name": "ipython",
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"version": 3
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},
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"file_extension": ".py",
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"mimetype": "text/x-python",
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"name": "python",
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"nbconvert_exporter": "python",
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"pygments_lexer": "ipython3",
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"version": "3.6.5"
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}
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},
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"nbformat": 4,
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"nbformat_minor": 1
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}

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