DEVLOG #3

What I did

So, I started with the Schematic on KiCad. I created symbols for the microcontroller and the LCD screen (since there weren’t ones on KiCad) and used the premade servo symbols for the continuous servos. I put them all on the page and wired them up in a way that made sense to me. I have never made a schematic before and did not know if my wiring was accurate. After that, I started on the BOM. I don’t have much on there yet, just details about the main components like the microcontroller and servos, but I will expand on it later.

Challenges

Making the schematic

I had quite a bit of trouble when making the schematic. This was mainly because I had never done this before and didn’t know what to expect. One challenge I faced was creating the symbol for the Microcontroller. I started by going to the product page on Seeed Studios website. I saw a diagram with all the pins and their functions, but I didnt know what to include. So I googled an image of a schematic using the microcontroller and found that people would often just label the external GPIO pins, so thats what I did. Another problem I faced was trying to find the pin numbers. I was able to find the name of each pin on the diagram from the website, but they didn’t list the pin numbers. So I decided to look at the data sheet. So I googled for the data sheet, found one from Seeed Studio, and copied the pin numbers from a table on the sheet. But I noticed that they didn’t label all the pins on there, specifically the 5V (VBUS) pin and GPIO43 (which turned out to be TX), which is when I began to look elsewhere. Then I noticed that other schematics were just labeling them as 1 - 14 along the pins, so that is what I did. I faced similar problems with the LCD, but I decided to exclude the pin numbers and to just name them depending on their function. After I had made both symbols, I moved onto the schematic. This was fairly simple, since I just had to connect the right pins. But I was a little skeptical as to whether I had wired up the power correctly, since I didn’t know how I was supposed to wire the battery to all the components. However, I looked at some simple example schematics with batteries to see how they were implemented, and based mine off of them. I decided to power the LCD from the microcontroller since it runs off of 3.3V and the battery is set to 5V, with the servos and microcontroller running directly off of the battery.

What is next

Next, I will probably order the parts that I know I will need and begin working with them. Sadly, the microcontroller is said to arrive a week from now, while all the other parts are going to arrive much sooner unless I purchase an unsoldered version of the board. I was thinking about buying an unsoldered version and then just tying wire around the pins to make connections since I don’t have a soldering iron, but I don’t know how good of an Idea that is. Any suggestions would be greatly appreciated.