Gather the materials below and get ready to build the Thimble WiFi Robot! As you follow through our tutorial, please know that we see this as a living document. If you discover anything unclear in the instructions, let us know and we will do our best to fix it as fast as we can. Each page of every module on our learning platform has a section for discussion at the bottom of it, so please use that to let us know about anything that is unclear. We believe strongly in the philosophy of empathy-driven development, and if something is unclear to you, it is likely unclear to others.
Our tutorials are meant to be a fun way to explore the world of electronics. We have included not only instructions, but also some theory, history, and challenges for you to explore on your own. If you only want to build the robot, you can skip over these discussions and links, but we encourage you to spend some time exploring and discussing all the resources we included here.
|WiFi-Bot v2.0 PCB||1|
|Laser Cut Platform||1|
|Laser Cut Motor Mounts||2|
|Laser Cut Rotary Encoders||2|
|Wire (For Motors)||1|
|Female Headers 1x4||3|
|Photointerruptor (Optical Switch)||2|
|Ultrasonic Module (HCSR04)||1|
|WiFi Module (ESP8266)||1|
|Battery Holder (4XAA)||1|
|Batteries (4xAA not included)||1|
Tools you'll need
We've found most people prefer following along in the tutorial step by step, clicking on the videos and images that accompany each video to look at more detail. However, some people may prefer to watch the entire assembly process first.
Assembling the PCB
The first thing to do is un-box your kit and lay the components out on the table. We'll start by assembling the printed circuit board (PCB). In the Arduino world, PCBs are commonly referred to as "shields."
We included a small "puzzle hunt" with the first kit. If you'd like to solve it, your first clue is on the back of the Thimble PCB. Examine it carefully. If you get stuck, we'll be posting hints in the forum. Once you've solved it, please don't spoil it for others.
The PCB comes with all of the surface mount parts (highlighted in the photo below) pre-soldered to the board.
We'll start by inserting the stackable headers into the PCB and using solder to tack them into place. These headers allow us to insert the PCB into the Arduino (or Arduino-compatible board) while still allowing us access to the sockets on top of the Arduino in order to add additional circuitry.
Once you’re done putting in all the headers on both sides of the PCB, carefully flip the PCB over. Use your fingers to keep the headers intact as you flip it over so they don’t fall out. This can be a little tricky at first but you’ll get the hang of it.
Now we're ready to start soldering! As mentioned before, start by using solder to tack the headers in place (only solder one pin for each header). Grab your soldering iron and solder wire. Place the soldering iron on the top right pin; slowly push solder wire into the pad and soldering iron tip. Solder should start to flow as you push it (solder should resemble a little dot or joint).
At this point, all headers should be soldered firmly onto the PCB. If you have made it this far, give yourself a firm pat on the back. You have soldered more than most people do in their lifetime. :-D
You may want to wait to solder the green terminal blocks until after you have soldered all of the other headers (black pieces) to the board. The terminal blocks are slightly taller and may make it more difficult for you to hold the pieces in place when soldering on a table top.
Now it’s time to solder the other through-hole components onto the PCB. Using your hands, take the little green connectors (aka terminal blocks) and attach them together. There is a little notch that will allow each green connector to slide into one another.
Once you have all the parts tacked in place, flip the board over and you're ready to solder all of the pins. Again, remember to be careful to make sure there are no solder bridges. A solder bridge is where two or more pins have solder touching. This is bad as it results in an electrical short (both pins will have the same voltage). Depending on the circuit, this can cause damage if we apply electricity. However, again, if you find yourself in this situation, don't dismay - it can be fixed! Just scroll up and watch the video about using a solder sucker and solder wick.
For the electrical connection of the motors, you'll need two sets of two wires and the wire cutters. We use the black and white wires included in the kit, but you can use the color of your choice.
Grab the piece of wire you need and gently strip the ends of the wire with your wire cutters.
Place the wire through the copper contacts of the motor on both sides. Then solder the wire onto the joint. Repeat for the other motor. Make sure the wire has some flexibility to it and wrap it around the motor so it will not rip the copper contact off the motor. You may want to use some hot glue here (after it is soldered) to provide some strain relief and ensure the wire will not rip.
Now you're ready for the last part of assembling the robot - the mechanical assembly.