The Make It Last Build Series Newsletter, Build #2, Dispatch #1
We're so glad to have you onboard for the Make It Last Build Series, sponsored by Microchip and Energizer.
This is the second build in a series of three. The series focuses on the theme of working with low power devices that use as little power as possible to conserve energy. If you're just joining us now, you may want to review the material from the first build, the data logger project
. In that project, we covered the basics of building a microcontroller circuit from scratch, programming it, and configuring it to sip power from a pair of batteries. This time, we're going to extend that knowledge to create something truly interesting, unique, and fun: robotic plant life! We'll create a robotic plant seed, that will be able to lay dormant for months, and at just the right moment, bloom into a beautiful mechanical plant!
These newsletters provide weekly updates about the contest, including each step of the build and explanations for each of the pieces that make up a microcontroller system, and provide inspiration and guidance to help you put your project together. The official contest rules and regulations can be found on the contest landing page
, which also houses the official sign-up form and links to everything about the contest. We'd love to hear from you, so don't hesitate to contact Matt or Gareth with any questions or concerns you might have about the builds. We've also set up a forum topic
specifically for this contest, so be sure to stop by and introduce yourself!
As a reminder, this contest is open to anyone who wants to learn about microcontrollers. Whether you're a seasoned programmer who wants to learn a bit more about hardware, or a beginner just starting to get your feet wet, don't be shy! We're looking forward to seeing how much we can all learn in the coming months.
Matt and Gareth
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Robotic Plant Life
For this build, we're going to create a robotic plant "seed" that will use its microcontroller brain to montior its environment, and bloom just when the time is right. The whole project will be housed in an ordinary plant pot, and thanks to an energy-efficient design, should be able to lie dormant for months, or even years, on a single set of AA batteries. That means you could set it by your window and forget it, or give it as a gift to a patient robot enthusiast.
To accomplish this, we'll need to use the low-power techniques that we learned in the data logger build, along with a few new tricks. Picking up from the final circuit used in that build, we will add a more accurate clock so that the plant can wake up at precisely
the right date and time, a capacitve input so that it can respond to touch, and a servo motor to allow it to grow and bloom. Our example build will use these sensors; however, you could program yours to respond to anything you want — perhaps light and temperature, like a real plant, or sound. We'll also provide instructions on how to convert an ordinary tape measure into a computer-controlled plant stalk, how to construct a flower petal from some wire and plastic, and some methods for packaging it all up. So, check out the parts list to see what you need to scrounge, and start thinking of what kind of plant you'd like to make. We'll start building next week!
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Gathering the Parts
Here's a list of the parts that we will be using to build the robot plant. There are a lot of things listed; however, you might have many of them already, especially if you participated in the data logger build.
- Soldering iron (with solder, of course)
- Pliers/wire cutters
- Scissors/X-Acto knife
- 18lf25k22 processor (Digi-Key PIC18LF25K22-I/SP-ND, $3.14)
- 1x 1uF bypass capacitor (Digi-Key P5174-ND, $0.20)
- 3x 10k resistor (Digi-Key 10.0KASCT-ND, $1.10/10)
- 4x 220 resistor (Digi-Key 220QBK-ND, $.35/5)
- 32.768 kHz crystal (Digi-Key 631-1205-ND, $0.48)
- 2x 22pF cap (Digi-Key VY1220K31U2JQ63V0, $0.64)
- N-channel transistor (Digi-Key NTD4960N-35GOS-ND, $0.62)
- 22 AWG solid-core wire (Digi-Key C2004B-100-ND, $15.97/100ft)
- .1" male headers (Digi-Key A26509-40-ND, $1.60)
- 28-pin chip socket (Digi-Key 3M5480-ND, $0.33)
- 3x Energizer lithium batteries (Digi-Key N602-ND, $3.93) (or similar)
- 3xAA battery holder (Digi-Key SBC331AS-GRN-ND, $1.75)
- Protoboard (RadioShack 276-170, $2.99) or (Digi-Key 438-1022-ND, $13.78)
- 3x 3mm red LED (Digi-Key 754-1218-ND, $0.10)
- 3x 3mm green LED (Digi-Key 754-1217-ND, $0.10)
- Continuous rotation servomotor (Digi-Key 900-00008-ND, $12.99)
One or more of these sensors:
- Temperature sensor (Digi-Key MCP9700A-E/TO-ND, $0.34)
- Photocell light detector (Digi-Key PDV-P9004-ND, $1.58)
- Metal pieces for capacitive sensing (cool button, spoon, etc)
Mechanical (this section is more flexible):
- Tape measure (Home Depot, $6)
- Wire (22AWG solid-core fence wire)
- LDPE plastic or similar sheet stock
- Lightweight or stretchy fabric, about 4"x8" (muslin, T-shirt fabric, etc.)
- Elastic thread (Try here or here)
- Cardboard, big enough to cover the top of the flower pot
- Shapelock plastic (for mounting the servo/tape measure)
- Decorative flower pot/box (6" diameter)
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Microchip Discount Code
Want to pick up a PIC programmer or development kit? As part of the contest, Microchip is offering a 20% discount on the following development tools:
PICkit3 Debug Express
ICD3 In-Circuit Debugger
XLP 16-bit Development Board
F1 Evaluation Platform
F1 Evaluation Kit
If you've been thinking about getting started with PIC programming, this could be a great opportunity to get a good deal on a programmer. To request a discount code, send an email to email@example.com.
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