What is Tessel?
In terms of hardware, Tessel has:
- Processor ARM 180 MHz
- 32MB SDRAM
- 32 MB Flash
- 20 GPIO pins
- Built-in WiFi (although the signal is weak so adding your own antenna is recommended)
The built-in WiFi is a great feature: in one simple command, my Tessel was connected to my home network, the details of which are then saved separately for all the programs you add, so that it will automatically reconnect every time.
There are 14 different hardware modules to add additional features such as infrared or RFID, although some are not yet shipping. They work similar to Arduino shields by inserting one of the module’s four Tessel connectors. If this happens in the same way as in Arduino, we should expect third party add-ons to appear pretty soon.
In the picture below: RFID and IR modules are connected to Tessel through 3 of 4 expansion ports.
Comparison with Raspberry Pi
Ease of use is the main differentiating factor. Installing Node.js on a Raspberry Pi is no easy task, and even with desktop graphical features disabled, Node runs at a snail’s pace. You will need to remotely connect to the Pi to edit files, and then there will be a wireless setup problem.