Description

The Smart Plant is an electronic board designed to help gardeners monitor the health of their plants. With its advanced sensor suite, the Smart Plant can measure soil moisture, ambient light, air temperature and air relative humidity. In addition to its IoT capabilities, Smart Plant features a 2.9” e-paper display, allowing you to read your plant data at a glance.

Smart Plant is designed to be highly energy efficient, featuring deep-sleep features on its ESP32 microcontroller that allow its battery to last for weeks at a time. When it's time for a recharge, Smart Plant can be charged using a USB-C cable or a small solar panel, making it an eco-friendly choice for gardeners who want to minimize their environmental impact.

Details

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...

However, I wanted something more... so I made it...

I started by making a breadboard behaving as a "shield" for the LILYGO TTGO T5 V2.3.1_2.13 Inch E-Paper where I could plug a capacitive soil moisture sensor and two I2C modules for ambient light (MAX44009) and temperature & humidity (BMP280) measurement.


Smart Plant V0R1 assembled	Smart Plant V0R1 front	Smart Plant V0R1 back

The breadboard worked so I moved to a customized PCB, this time embedding a 555-based circuit for the capacitive soil moisture sensor and the ambient sensors (light and temperature). On this prototype, I also added a circuit to allow the selective powering of the sensors, with the aim of bringing down the total power consumption after entering the microcontroller into a deep-sleep mode.


Smart Plant V0R2 assembled	Smart Plant V0R2 front	Smart Plant V0R2 back

I also added a circuit for directly reading the soil conductivity through two electrodes (similar to what the Mi Flora does), but after testing it I ended up discarding it, for not finding a good solution to the electrolysis on the terminals that happened after some months of usage. I even added stainless steel rivets to cover the exposure of areas that could get affected, but with enough time it also got affected.

Since it wasn't a measurement parameter that I would miss that much, I moved with the rest of the board functionalities working (or rewiring and fixing the errors in order to get them working).

This trial and error path, brought me to the current design the Smart Plant (V1R1).


Smart Plant V1R1 assembled	Smart Plant V1R1 front	Smart Plant V1R1 back

On this board, I integrated an ESP32-S module and I upscaled the e-paper from the 2.13" on the TTGO to a more easy-to-read 2.9" display, together with all the sensors integrated and a LiPo charging circuit. But let's analyze each system individually:

ESP32-S

This is the brain behind, the microcontroller powering the board. Its IoT capabilities (Bluetooth and WiFi), together with the support for a good suite of GPIO, digital busses like the I2C, and the deep-sleep mode feature makes it the ideal candidate for a solution like this. In addition, the community support with firmware like ESPHome or platforms like Arduino set the decision and since I didn't want to get things more complicated than what I already had, I decided to use directly an ESP32 module.

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 because the integration into Home Assistant is (almost) immediate.

One of the critical tests asked for this new design was the low power consumption: for this test I configured the board to be awake 10s and into a deep-sleep mode for 1h. The results were pretty good, achieving an average of 450-500μA in deep-sleep mode and a combined consumption of 1mA per hour. This translates into approximately 5-6 weeks of usage for a 1000mAh battery updating the display (and the Home Assistant) each hour.

With the aim of reducing costs and due to the limited space on the board, I decide not to implement a USB-to-UART IC, such as the CP210x or the CH340G, instead, I use an external USB-to-UART device and the rest of firmware updates I do them OTA (Over The Air) with Home Assistant.

Battery Management

The battery management system consists of the LiPo charging circuit and the voltage regulation to provide...

Components

1 × Smart Plant board This is the designed board that host all the circuits and the components that bring the Smart Plant project alive

1 × 2.9" e-paper display The recommend (and tested working) display is the `296x128, 2.9inch E-Ink raw display panel (https://www.waveshare.com/product/2.9inch-e-paper.htm) that you can order directly on the manufacturer.

1 × 1000mAh LiPo battery The ideal dimensions shouldn't excess the 50x34x5mm in order to fit in the designed enclosure.

1 × 3D Printed enclosure The one I designed, despite not being fully waterproof, does a good job protecting the electronics agains eventual spilled drops of water while watering the pot

1 × Solar panel In addition to the USB-C, and with the aim of extending the service time between (USB) charges of the battery, the Smart Plant can be powered from a solar panel.

Project Logs

Collapse

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:

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.
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.

Discussions

funky wrote 06/21/2023 at 12:18

I'm new with hackaday. Is there a way to order this device?

upd. Ach, found it, it was in the More → Tindle Marketplace menu: https://www.tindie.com/products/jgaguado/smart-plant/

Is the new batch expected?

Are you sure? yes | no

bcmallory wrote 06/15/2023 at 03:34

Jon, is there room to add easily more data points (sensors) from a general standpoint without affecting the current specifications like battery life. I started a similar concept using Amazon Sidewalk sensor with the intention of adding and expanding Wi-Fi limitations, like a greenhouse and used on a semi mass scale designed for commercial growth operations. For example the the legal medical cannabis industry. I’d love to learn more about your project and pick your brain.

Are you sure? yes | no

Jon wrote 06/30/2023 at 11:53

I'm not sure I understood correctly your message, can you send me a PM?

Are you sure? yes | no

DomoAlegres wrote 05/31/2023 at 19:09

Hi Jon,

I'm a bit of a learner.
I just got the "Smart Plant" card.
I have installed the ESPHome "Add-on" on my Home Assistant.
The Smart Plant card communicates well with my Home Assistant and I have already included it in my panel.
But I have a problem when trying to update it.
I get the following error and I don't know what is the problem.
Might be useful for other people too...
Thanks in advance.

--------------------------------------------

INFO ESPHome 2023.5.5
INFO Reading configuration /config/esphome/smart-plant-38d518.yaml...
INFO Detected timezone 'Europe/Madrid'
WARNING GPIO15 is a Strapping PIN and should be avoided.
Attaching external pullup/down resistors to strapping pins can cause unexpected failures.
See https://esphome.io/guides/faq.html#why-am-i-getting-a-warning-about-strapping-pins
Failed config

esphome: None
name: smart-plant-38d518
name_add_mac_suffix: False
includes:

Could not find file '/config/esphome/libraries/icon-map.h'. Please make sure it exists (full path: /config/esphome/libraries/icon-map.h).
- libraries/icon-map.h
project:
name: smart.plant
version: 1.2
on_boot:
priority: 600
then:
- lambda: Wire.begin();
delay(100);
build_path: .esphome/build/smart-plant-38d518
image: [source /config/esphome/.esphome/packages/a3053235/docs/source/files/configuration.yaml:77]
-
Could not find file '/config/esphome/plant_labels/Lemon_tree_label_page_1.png'. Please make sure it exists (full path: /config/esphome/plant_labels/Lemon_tree_label_page_1.png).
file: plant_labels/Lemon_tree_label_page_1.png
id: page_1_background
font: [source /config/esphome/.esphome/packages/a3053235/docs/source/files/configuration.yaml:81]
-
Could not find file '/config/esphome/fonts/Audiowide.ttf'. Please make sure it exists (full path: /config/esphome/fonts/Audiowide.ttf).
file: fonts/Audiowide.ttf
id: font_title
size: 20
-
Could not find file '/config/esphome/fonts/Audiowide.ttf'. Please make sure it exists (full path: /config/esphome/fonts/Audiowide.ttf).
file: fonts/Audiowide.ttf
id: font_subtitle
size: 15
-
Could not find file '/config/esphome/fonts/Audiowide.ttf'. Please make sure it exists (full path: /config/esphome/fonts/Audiowide.ttf).
file: fonts/Audiowide.ttf
id: font_parameters
size: 15
-
Could not find file '/config/esphome/fonts/materialdesignicons-webfont.ttf'. Please make sure it exists (full path: /config/esphome/fonts/materialdesignicons-webfont.ttf).
file: fonts/materialdesignicons-webfont.ttf
id: font_icon_battery
size: 20
glyphs:
- ó°º
- ó°»
- ó°¼

-------------------------------------------

Are you sure? yes | no

Jon wrote 06/01/2023 at 12:21

Dear @DomoAlegres ,

Just the configuration YAML file isn’t enough and you might get an error asking for missing items (the fonts and the images). The reason is because on the configuration we are asking for some files (the fonts that you want for the digits or the icons and the background image with the plant and the gauges).

Therefore you need to upload into the folder with the configuration YAML file the required files. I strongly suggest using Visual Studio code and just drag and drop the items according to the structure mentioned on the esphome programming section (https://smart-plant.readthedocs.io/en/latest/programming.html)

Best regards,

Jon

Are you sure? yes | no

DomoAlegres wrote 06/01/2023 at 16:05

Hi Jon,

Thanks for the reply.
I was following the Github "programming.rst" document, but not all the information appears there, but it does appear complete on the page you indicated (https://smart-plant.readthedocs.io/en/latest/programming .html) and had misunderstood the process to follow.
I'm going to follow the steps listed here.
An additional question: Is there a procedure to clear the parameters of the "Smart Plant" card and return to the factory settings?
Thanks and best regards.

Are you sure? yes | no

michal wrote 04/14/2023 at 07:35

Hi Jon,

How do you handle time in your esp ? I can't see any external RTC, or XTAL for internal one. Do you get time from NTP ? What in case there is no internet connection ?

My experience with internal RTC during sleep is very poor, it is not accurate at all.

Are you sure? yes | no

Jon wrote 04/14/2023 at 08:05

Hi Michal, currently, the ESP's timekeeping relies solely on its internal RTC to keep the design compact and straightforward. And yes, you are right, the deep-sleep timing is not very precise. In my experience, I have observed a loss of around 1-2 minutes out of every hour, resulting in a deep sleep period that lasts around 58 minutes instead of 60. However, given that the clock's accuracy is not critical for my application, I do not see a compelling reason to integrate an external RTC into the current design.

Are you sure? yes | no

mrwho wrote 04/12/2023 at 21:24

Looks great, but still has a weak point. These capacitive soil moisture sensors don't hold up for very long.
Sooner or later either water seeps through the PCB layers or the laquer coat cracks (usually
starting from the tip = mechanical stress) and destroys the copper layers.

A connector for spare parts would be an advantageous design.

Are you sure? yes | no

Jon wrote 04/14/2023 at 07:55

Dear @mrwh, I appreciate your interest in the project. As you mentioned, while FR-4 (the fiberglass-reinforced epoxy laminate used as a substrate for my PCBs) is not hygroscopic, it can absorb moisture over time, which can negatively impact the performance of the PCB. Applying a conformal coating, such as silicone or acrylic-based coating, can create a barrier between the board and the environment, ensuring long-term reliability and performance.

However, from my experience with the early-stage versions of the project (V0R1), I have found that the solution you suggested may be less reliable in terms of durability. Not only you can end up with corrosion in the connector metallic pins depending on the ambient moisture, but also, the connector itself would have to behave as a mechanical interface between the upper part (display, electronics, battery and enclosure) and the bottom soil moisture probe. This means that, every time you touch the device, the connector will be subjected to mechanical stress, increasing the chances to fail.

Are you sure? yes | no

Marius Schäfer wrote 04/12/2023 at 17:03

Great project!

Are you sure? yes | no

Jon wrote 04/12/2023 at 17:50

Thanks Marius!

Are you sure? yes | no

Giulio Pons wrote 04/12/2023 at 16:28

Very nice. I like it a lot.

Are you sure? yes | no

Jon wrote 04/12/2023 at 17:01

Thanks Giulio!

Are you sure? yes | no

seancriggs wrote 02/24/2023 at 16:27

Fantastic project! Well thought through and developed!

Curious, how long did it take you from concept to v1?

Are you sure? yes | no

Jon wrote 02/24/2023 at 17:45

Hi Sean, thanks for your support! I would say around 6 months working intermittently on the weekends. I made some other boards in parallel to complement the "Smart Domotics" setup that I hope to post soon.

Are you sure? yes | no

Dan Maloney wrote 02/24/2023 at 00:29

Hi Jon --

Very nice build, everything looks so well thought out! I wrote this up for the blog, should publish soon. Good luck in the contest!

Are you sure? yes | no

Jon wrote 02/24/2023 at 10:10

Thanks Dan, looking forward to read it :)!

Are you sure? yes | no

Smart Plant

Description

Details

ESP32-S

Battery Management

Components

Project Logs

Collapse

From PCB to PCB Assembly with JLCPCB

V1R2 is here!

Discussions

Similar Projects

Bin Level Monitoring

Captain Pugsley - Smart motion sensor

Smart Powermeter

ESPmobe - battery powered ESP32 IoT-sensor

Smart Plant

Become a Hackaday.io member

Just one more thing

Description

Details

ESP32-S

Battery Management

Components

Project Logs Collapse

Enjoy this project?

Discussions

Become a Hackaday.io Member

Similar Projects

Does this project spark your interest?

Report project as inappropriate

Send message

Remove Member

Project Logs

Collapse