picopasco

- to feed oneself a little bit

description

sensor monitor and control hardware/firmware for a personal economical and scalable grow system using a raspberrypi pico and standard off the shelf sensors and components.

present state

includes nutrient mixing capabilities and monitor of the following sensors.

• air temp
• water temp
• humidity
• volatile organic compounds
• carbon dioxide
• soil moisture - see irrigation
• tds
• ec
• pH

see vids and picts for more details.

wiring diagram:

features

• nutrient mixing

four liquid reservoirs using relay triggered solenoid valves for mixing water with up to three nutrients. User inputs nutrient tank capacity, target EC/TDS, nutrient mix ratios, and mixt interval then the system automatically mixes and fills the tank. Mix may also be triggered externally for point of use.

• water quality

The tds/ec sensor can be used as a continuous monitor to ensure the water quality is within the target range and compensate for drift by adding water or nutrients.

• irrigation

moisture sensor monitors the grow media and can trigger irrigation. The nutrient mix can then be used to irrigate multiple grow mediums like hydroponic, aquaponic, or terrestial systems. See picopasco-water for controlling irrigation based on moisture sensor feedback.

• air quality*

includes temperature, humidity, co2, and volatile organic chemical (voc) sensors.

*-present state only include closed loop feedback for mixing additional relays may be added to control irrigation, air quality, and/or lighting

• power

  • specifications

    • quiescent (sensor only) - 0.25 watt
    • maximum (all valves open with sensors scanning) - 4.00 watts* *operation limited to 1 pump at a time with relay triggering 1.75 watts

  • requirements

    • supply

      • on grid: ac to 5 volts transformer 5 watts
      • off grid solar battery bank approximate 15 watts >=15000 mah

libs:

• sgp30 gas sensor
• sht4x temp/rh

parts:

minimum (by firmware design)

• $6.00 rp2040 pico - (pico w optional)
• $5.50 grove sht4x temp/rh
• $17.50 grove sgp30 voc/co2
• $14.00 water quality tds/ec
• $34.99 pH sensor
• $7.99 relays 5 volt spst - 4x bank
• $12.98 5 volt pumps 4x - (alt solenoid option)

$98.96 Total cost of materials

optional

(intended by firmware design but not required)

• grove soil moisture

• rp2040 grove breakout

• 5 volt solenoid valves 4x

• sx1262 lora(wan) raspberry pi pico hat

future upgrade:

• rfm95 lora p2p
• lorae5 lorawan)
• wifi/bt/mqtt

status

• ✅ sensor firmware
• ✅ bench verify hardware
• ✅ wiring schematic and pinout
• ✅ relay trigger firmware (mixing)
• ✅ integrate sensor and mixing code (See V3.0+)
• ✅ platformio and arduino compatible
• ✅ pH sensor
• pid control mix to target setpoint pH/tds/ec - firmware in process
• sx1262 lora/wan - bench testing gpio20 conflict with relay changed to 15,16,17,18 v4.0
• wifi/bt/mqtt

plan

• controls

  • lighting timers
  • hvac triggers pid control

• connectivity

  • wifi
  • +lora(wan)
  • mqtt

• ui

  • local wifi/bt
  • remote mobile app

• portability

  • alternate mcu
    • xiao
    • esp32
    • wioterm
  • platformio build/flash verify

• vids

  • example of runtime firmware output
  • testing minimum response time of relays. 3 ms is the mininum trigger dwell otherwise relays fail to actuate mechanically.
  • max power consumed 350 ma @ 5 volts [1.5 watt] during dry pump cycling.
  • initial power on test partial vacuum build up induced syphoning effect.
    • solved with shorter tube length and shorter elevation head.
    • optional solenoid shut off valve in <AND> with pump SPST relay NO trigger will provide a failsafe engineering control.

• picts

If you are interested in contributing or participating in this project contact GrayHatGuy@GrayHatGuy.com