Overview

The Smart Plant was designed to be flashed with the ESPHome firmware, however it can be directly programmed through Arduino or ESP-IDF. And since the code is yours, so it's the data you gather, stream it to your Home Assistant server and automate your irrigation on the plant's demand!

Want to get one?

In any case, all the design files are available on my Github, and I have prepared an extended documentation page for any user willing to know more about the project

Specifications:

Microcontroller: ESP32-S2-MINI-1-N4R2 with 4 MB in-package flash and 2MB PSRAM
Firmware compatible:
- ESPHome, highly recommendable for its native integration into Home Assistant
- Arduino
- ESP-IDF
Sensors:
- Soil moisture: Capacitive probe built-in
- Light: VEML7700-TR digital sensor
- Air Temperature & Humidity: AHT20 digital sensor
- Battery level: MAX17048 digital sensor
Power:
- 3.7V 1000mAh LiPo battery
- Charging through USB-C or solar panel (5V @500mA)
- Deep-sleep mode consumption: 450-500μA
- Standard mode consumption (10s awake, 1h deep-sleep): ~1mA
Interface:
- USB-C for charging and programming
- UART port
- 2.4GHz Wifi
Display: 2.9" black & white e-ink from Waveshare

Version log:

Version 0: Very early prototypes to serve as proof of concept.
1. V0R1: Protoboard with headers to be used as a shield for the TTGO T5 e-ink module
2. V0R2: PCB designed to host the same module but with some additional THT components integrated
Version 1: First designs on black PCBs with a more aesthetically oriented design.
1. V1R1: Integrated the ESP32-S module and a photodiode as a light sensor
2. V1R2: Corrected previous power module and replaced photodiode with LDR
Version 2:
1. V2R1: Replaced ESP32-S with ESP32-S2, added battery level sensor and digital light sensor.

The story behind

I started this project because I was missing some features on the popular Xiaomi Mi Flora. Those devices, despite being very useful, lack a key point: readability. Every time I wanted to check my plant's health I had to go to their app... With time I learned how to implement them into Home Assistant, receiving the data via Bluetooth on my RPi 4 and plotting the graphs I needed on my custom dashboards...

One day, I realized one of my Xiaomi's sensors was missing on the balcony pots. After an inquisitive search party, I found out that one of the black ravens from my neighborhood just decided to add this gadget to his collection of stolen items...

AI sketch of the suspected thief on the crime scene

With a pot missing a key instrument for the plant's survival, I decided to come up with an alternative gadget that, not only would keep the features of streaming the data into my Home Assistant setup, but also provide more of a user-oriented readability features.

Daily usage: automations

I chose ESPHome as the main firmware for the Smart Plant, not only because of the direct support for the e-paper panel and the rest of the sensors on board but also because the integration into Home Assistant (HA) is immediate.

Through HA you can flash ESPHome directly on the Smart Plant and start logging the parameters from the first minute. Additionally, you can prepare beautiful dashboards to display the data and set some automations.

In summer, I have the Smart Plants on my balcony plants (4 different pots). Each of my pots have an individual irrigation pipeline that I control through my other project Smart Garden and the assistance of some automations programmed in HA. The automations do basically:

At a certain time of the day (20:00), the system checks the moisture...

Smart Plant V2R1 for sale!
Jon • 01/21/2024 at 20:06 • 0 comments

Dear Hackaday community,

Exciting news for all you green-thumbed enthusiasts! The Smart Plant project has reached a new milestone, and I'm thrilled to announce that Smart Plant Kits are now available for purchase on:

Smart Plant Kits are available on Elecrow in a limited amount of units, so be fast and get yours! Each kit includes all the components you need to assemble your own Smart Plant device, along with detailed instructions to guide you through the process that you can find, as always, on the documentation.
Don't miss out on this opportunity to make your plants the smartest on the block!
From PCB to PCB Assembly with JLCPCB
Jon • 08/28/2023 at 17:16 • 0 comments
As part of a recent partnership with JLCPCB, an excellent PCBs (and PCB Assembly) manufacturing service that has manufactured the previous versions of the Smart Plant, I would like to share my personal experience and the seamless process of ordering PCBs with them.

1. Generate the Gerbers, BOM, and PnP files
- For the set of files, since I work on EAGLE, I use their CAM template (https://jlcpcb.com/help/article/9-How-to-Generate-Gerber-and-Drill-Files-in-Autodesk-Eagle), proven to work perfectly.
- Regarding the assembly files, I recommend following their tutorial with a specific ULP for EAGLE (https://jlcpcb.com/help/article/82-How-to-generate-BOM-and-CPL-from-Eagle-CAD-automatically)
2. Upload the Gerbers on their online platform and select the options you want: soldermask color, thickness, surface finishing... quite a lot of options and a very low starting price of just $2 for 5 pieces under 100x100mm!

3. If your project requires the assembly of components, here is where JLCPCB really stands out. Their internal access to thousands of components makes it very easy.

My recommendation for lowering your expenses and optimizing your design is to take into account their stock (doesn't need to be 100% available since they can backorder components for you) since your preliminary design phase. This way you can estimate the costs of the components and get the datasheet and footprints directly from them.

Also, in order to make the BOM export easier, if you use their ULP and for each component, you can add (in EAGLE) an attribute named LCSC with the value of the JLCPCB part #, there will be no confusion between components at the moment of ordering the PCBA. You can get to know more about this process in their tutorial

4. Once you have finished with the selection of PCB features, you can select, on the PCB assembly process whether you need an Economic or a Standard process. Unless you need to mount specific components (like certain ESP32 modules) that might require particular reflow temperature curves, the Economic option is the way.

5. Uploading the BOM and PnP, and verifying that all the components correspond with your intended ones, is very fast and easy.

In addition, you will be able to see a rendered image with the components in each place!

6. Before entering into production, their team will contact you in case they have questions regarding final positioning or polarities to avoid surprises and in a few days your order will depart from their facilities to you!
Since they work with worldwide shipping companies, in just a few days you will receive their blue box containing the boards. They come exceptionally well-packed and protected.
V1R2 is here!
Jon • 04/04/2023 at 14:51 • 0 comments
Following up with the great interest of some of you, I have good news: the next revision of the Smart Plant is here, the V1R2!

In this small revision, from which I ordered a first batch of 30 units, the following minor issues were fixed:
1. The Battery Management system is now fully embedded in one board, allowing not just the charging of the battery and the 3.3V regulation with the minimum standby consumption (for the deep-sleep periods) but also monitoring the battery through the ADC port (GPIO35) of the ESP-32 and implementing diodes for protecting the charging from a solar panel and the USB-C port.
2. The light sensor on the SMD factor has been replaced with a 5mm LDR footprint through-hole (THT) solderable. However, I haven't tested all the light conditions with a standard 5-10k GL55 photoresistor, but since it is a THT component the option to replace it with a 5mm photodiode is still there.