I am currently building a weather station that can measure temperature, pressure, humidity, and air quality, of which vaules are sent over wifi. The purpose of this build is to help me better understand how to build solar-powered and battery-powered applications.
Waiting on a reviewer. We'll let you know as soon as there's a decision.
|Drafted PCB Routing| In the many routing sessions, I was able to completely connect the components on the PCB to each other. The first thing I did was set the second layer to the ground plane in order for all components to have a reference layer. Then, I proceeded to route the power section. I used multiple power puddles, which is a new method that I am trying out. After the power section, I routed the MCU to the Sensors, and then did the RF section. For the RF section, I made sure to add tons of vias in order to protect the sensitive RF line from noise. When refining the routing, I had to reroute many things in order to make space; this is what took the most time of out the whole PCB routing session. All in all, I am ready to start finalizing the draft, and most likely, I am going to ship this project next session.
|FINISHED PCB LAYOUT| In this session, I was able to lay out my PCB. I created a draft Layout and then a final Draft. I split the PCB into 3 sections: Sensors, Power, and RF + inputs. I tried my best to make the PCB visually pleasing while keeping it electrically stable.
|FINISHED SCHEMATIC| Finishing the Schematic and assigning footprints took many sessions, which not all of them were logged. I added some Jumper points to be able to change some values for some of the ICs. Also, I chose actual parts for each component which was very time consuming. Next up is the PCB design.
|FINISHED SCHEMTIC DRAFT| In the many session I put into getting a rough draft of my weather station, I changed some ICs, added new things, and connected everything up. First of all, I added ESD protection ICs to both USB-C ports, and swapped the GPS module I had before, for one with a already integrated GPS receiver. Also, I swapped the AMS1117 3.3V linear regulator for a MCP16362T buck converter that will convert high solar panel voltage to 3.3V more efficiently, therefore saving battery power. Furthermore, I added a cell balancing circuit to keep the battery cells balance to prevent any future damage to the battery cells.
|Started BMS Schematic| In this session, I researched how to build the BMS system and implemented some of the circuitry needed to run the ICs.
|Worked on schematic| In this session I added more of the the decoupling and power components to the ICs, and drafted wiring of USB functionality to both MCUs.
|Organized Schematic| In this session, I added some new ICs and organized the schematic. It took a couple of days of research to start picking a good IC for the battery Management System, but I settled on the LTC4015 from Analog Devices. The LTC4015 supports LiFePO4 battery chemistry and includes built-in power-path circuitry and MPPT for solar panels. I decided on a 2S2P (2 batteries in series, with each series having 2 batteries in parallel) to get good voltage and capacity.
|Started Project| This is my first Session designing my Weather station PCB. I am building a weather station to expand my knowledge of sensors, low-power systems, battery-powered systems, and RF. In this first session, I added most of the sensors that are being used in the weather station and the two MCUs. All in all, this was a quick session to layout all the components I want in my weather station.
