In my projects I needed a tool to monitor data in real time, the data is captured by a microcontroller and uploaded to the web using a wireless router. Initially I was trying to use yeelink since it is in chinese langguage and yet I'm a Malaysian Chinese.
One month ago, I have tried with Ubidots, there were a few things that caught my eye.
The TP-Link TL-MR3020 N150 3G/4G Travel Router is a very small device with a size of 74mm x 67mm x 22mm, it has only 4MB flash and 32MB memory. The router have about 428KB (67%) space available after installing OpenWRT Barrier Breaker 14.07, you may encounter shortage of storage when installing certain extensions due to limited of router space.
By employing OpenWrt's extroot, you can expand the storage capacity of your root file system using the additional space of an added storage device.
This is a Queuing System project requested by a clinic asistant which allows the doctor enter number from a keyboard and display it on a 32x16 LED panel.
This project uses two Arduino, the first Arduino functioned as a SENDER which included a PS2 keyboard and a mini LCD for number input. While the other Arduino is functioned as a RECEIVER which will trigger a "ding-dong" tone and display number on the 32x16 LED panel.
The SENDER uses a PS2 keyboard instead of USB keyboard, USB keyboard will cost higher since it require a USB host shield. You should get a Matrix keypad (please use google translate) in case the PS2 keyboard is not available in the market.
These two Arduino (SENDER & RECEIVER) is connected via a CAT5e network cable, the CAT5e cable provide power to the RECEIVER and also transfer data between two Arduino.