• Big Hardware Update

    Jonathan3 days ago 0 comments

    Intro:

    last week I was working on a few different parts of MycoHub's hardware, as well as pushing the software along for the controlled environment. 

    1.  Added the ceiling / Raspberry Pi pan to the MycoBox and varnished it
    2. Modeled how the Laminar flow will fit on the MycoLab (above the Raspberry Pi pan)
    3. Created a prototype board to organize the sensors' and relays' wiring to the Raspberry Pi
    4. Switched the AC port with a much smaller one

    1 ) Raspberry pi pan & the MycoBox ceiling 

    ^ MycoBox flipped upside down to varnish the ceiling, all of the interior wood is double varnished

    ^ Raspberry Pi pan (MycoBox attic / MycoLab basement)

    The Raspberry Pi is positioned in this 4.5" deep pan above the MycoBox. The sensors will drop into the MycoBox, the relay wires will come through a port on the left of the Raspberry Pi pan, and the wires from the fans on the right side of the box cross through this section to reach the relays on the left as well. This way all wiring is above the MycoBox and below the Mycolab, while the main power lines are kept safely in a junction box on the left side of the MycoBox.

    ^ Junction box for the 2 relays. This is just showing how the relays will fit inside the box, I will actually assemble and mount this tomorrow.

    ^ This 4.5" spacing, as mentioned in a previous post, gives enough room to add ventilation fans to the Raspberry Pi pan; which may not be necessary, but just incase things get hot after running the MycoBox for a 4 week fruiting session. It also raises the MycoLab to the perfect standing desk height for me, I'm 6'2". 

    2) 16" x 16" x 11.5" Laminar Flow

    ^ This is not constructed yet, just demonstrating the spacing and location of the laminar flow. The 16" wide filter gives enough room to inoculate grow bags comfortably, and it takes up less than half of the available table space. It's also of course very easy to start agar plates, or do any other lab work in front of this. 

    ^ This is image is just showing the amount of space left available. I haven't added the remainder of the ridge that lifts the MycoLab above the MycoBox, and need to get another board for the base of the MycoLab; I accidentally did a terrible job sizing and cutting the board the first time.

    ^ This is a 273 CFM centrifugal blower fan, which is enough to keep the air speed through the filter well above 100 fpm. I determined the minimum required fan speed by multiplying the 1.77 foot surface area of the filter by the 100ft/min rate air speed, which calculates to a 177CFM fan. The space behind the filter is 6" deep and will be a closed box that the fan mounts on top of. The fan itself will also be in a closed box with the only vent having a pre-filter on it, which is to keep larger particles from ever reaching the laminar flow filter. It will be built in a way that makes it easy to slide the filter out for replacement when the time comes.  This is pretty much the only hardware that won't be connected to the raspberry pi, there will simply be a switch for turning the fan on or off. 

    3) Raspberry Pi Prototype Board

    I created a prototype board to organize the bird nest of sensor and relay wires connecting to the Raspberry Pi GPIO. Instead of plugging into the default GPIO each sensor and relay gets a designated plug.

    ^ finished version 2 ( I had to scrap the first attempt and change the design). The left most pins are for the 8 channel relay (relay 2), and the row second from the left is for the 4 channel relay (relay 1). The top middle pins are for the MAX31855 thermocouple, and the 4 others in the middle are for DHT22 sensors. The first three DHT22s will be placed in the bottom, middle, and top section of the Mycobox, while the 4th is tracking the temperature and humidity outside of the box. The thermocouple is very precise and will have the most weight for controlling the PID that maintains the box temperature. Finally, the right most pins are for the co2 sensor, which is mounted...

    Read more »

  • Programming the WiFi/USB Scale

    Jonathan07/17/2021 at 00:33 0 comments

    Intro: 

    The scale is to track the exact weight in pounds of mycelium or mushrooms grown over the period of a session; spawn running or fruiting. For anyone that's interested in growing mushrooms for profit, it's good to know exactly what substrate and supplement mixture produces the most grams of mushrooms. Mushrooms or mycelium, it's good to know exactly how much is being produced under various conditions. 

    Initial Idea:

    Initially the scale was to be wired directly to the raspberry pi, since the raspberry pi was originally to be positioned directly in front of the scale. I also planed to connect all 5 wires from the HX711 load cell amplifier, the board that reads the 4 load cells of the scale, directly to the raspberry pi. This takes up a lot of GPIO and requires the scale to always be directly attached to the raspberry pi, which isn't the best option

    New idea and why I'm changing the design:

    I'm now using a generic esp8266 WiFi board as the controller for the Sparkfun HX711 load cell amplifier. The esp8266 can easily receive HTTP commands from the raspberry pi, or be plugged in via usb serial communication. This way the scale can be used wirelessly, outside of the mycobox, or plugged in when it needs to be recharged. 

    This is a picture of the original HX711 board (Green) I tried to use, it had a problem with noise and required one of the pins to be desoldered and connected directly to another. I've done such hacks before but decided it's better to buy a better board (Red) that's not broken in the first place for this project.

    This is wiring is a 'wheatstone bridge" circuit for connecting the 4 load cells positioned on the board. The load cell amplifier in the middle has a 24 bit analog to digital converter that can report the readings from the load cells to a microcontroller. 

    This video shows the clearance of the scale, it's just high enough for the boards to not get in the way. 

    programming the scale is pretty simple as well, there is a great library that takes care of the hard work for you; it comes with a calibration script and plenty of other examples.

    In the above video I zeroed out the scale with the grow rack on it, then calibrated the scale with a 5lb bag of substrate.

    Summary:

    I've created an accurate rough draft of the wireless scale that will track how much mycelium or fruiting mass is grown during a session. I need to add some code to the esp8266 for receiving and sending http requests to the raspberry pi via wifi/ or communicating directly via usb serial if it's plugged in. I also will be adding a small rechargeable battery circuit so that the scale will have power even when it's not plugged in, making the wifi capability practical. But for now I'm switching back to programming the MycoBox "enviornment manager" program, since all of the sensors and relays are now functional. 

  • MycoHub wiring design consideration update

    Jonathan07/16/2021 at 15:22 1 comment

    Intro:

    I initially started this project intending it to be just the 'MycoBox', a raspberry pi monitored and controlled chamber for spawning and fruiting. However, I soon realized the MycoBox is nearly a perfect bench-top space for including a complete mycology lab as well! So, my wiring design is in need of an update. 

    Initial Idea:

    I like to keep data and clock lines from my controllers to my sensors as short as possible, as a best practice I think, so I intended to place the raspberry pi in an insulated box inside the chamber right below the sensor pole ( front door pole that holds the CO2, humidity, and temperature sensors). 

    This way I could run relay wires under the floor and over to the relay panel out of sight, and run a few data lines neatly up the pole to the sensors. 

    New idea & why I'm changing the design:

    •  I can keep the raspberry pi completely out of the chamber and place it in an air ventilated section above the MycoBox and below the MycoLab (components of the MycoHub).
    • The MycoLab slides into place on top of the MycoBox and can easily be lifted and placed aside to access a very accessible electronics pan. I think this is just a nicer UX for anyone that may need to maintenance the sensors, or relays, or access the raspberry pi, or any other electrical wiring. 
    • It will also be easy to include wiring and control for the mycolab here as well
    • when the MycoLab is seated into position on the MycoBox, it plugs into the power supply and control circuit
    • I wanted to raise up the MycoLab a bit by rimming the MycoBox with 2x4 boards so that it's at a more ergonomic standing lab height (you could use a stool as well)
    • The flat grey fan is my previous spacing idea, keeping the tray at 1.5" depth. However, I plan to raise the MycoLab up just a bit higher anyways, so now there's just a more generous amount of space to work with.
    • The increased pan depth also gives more room for adding a nice thick, not thin flimsy, board for the bottom of this space and the ceiling of the MycoBox; which I think is better. Also a bit more room for any insulating/heat resistant layering I put down in the tray. 

    Summary: The Raspberry Pi will live above the MycoBox and below the MycoLab in a ventilated access panel for easy construction and maintenance, instead of inside the MycoBox chamber.