Long gone are the days of parallel ports and serial ports. Now the USB port reigns supreme! But USB is hard, and you just want to transfer your every-day serial data from a microcontroller to computer. What now? Enter the Adafruit CP2104 Friend!

This is a high-quality CP2104 USB-Serial chip that can upload code at a blistering 2Mbit/s for fast development time. It also has auto-reset for Arduino/ATmega328 boards so no noodling with pins and reset button pressings. The CP2104 has better driver support than the CH340 and can do very high speeds, and variable speeds without stability issues. Compared to the FT232RL and FT231X, the CP2104 has the same capabilities or better, at a great price! It even has the RX/TX LEDs to help you debug your data, they'll blink when the chip receives/transmits data.

By default, we've set it up so that it matches our FTDI cables. The 6th pin is RTS, the power wire is +5V and the signal levels are 3.3V (they are 5V compliant, and should work in the vast majority of 3.3V and 5V signal systems). Works excellently with any Arduino, ESP8266, ESP32 or any other microcontroller that uses an 'FTDI port' for communications and upload. You can also purchase a 6-pin extension cable from us, which will let you rearrange the wire order.

There's also a full collection of all the modem control pins you may need on the side, in case you need the DTR, RI, DSR, etc. pins.

Each order comes with a fully assembled and tested board. We give you a right-angle socket header and some male header strip. You can solder in the socket header on the edge to make it 'FTDI-like' or solder the male headers in to plug it into a breadboard and get access to all the pins.

For Linux you won't need a driver. For Windows, it will automatically grab the driver from Windows Update. For Mac OS X you can check out SiLabs driver page for the latest and greatest.

Here's another super handy add-on for your Raspberry Pi computer, perfect for 'head-less' setups! The PiUART adds a MicroUSB to serial connection so you can use any serial port software to connect to the Pi's console. It plugs in and is fast and easy to add whenever you need to connect to your Pi. Two LEDs connect to RX and TX on the serial converter chip so you get blinking whenever data is sent or received.

We had some space left over, so the PiUART also comes with an on-off switch with a 4 Amp transistor. You can power your Pi through the microUSB port and then use the switch whenever you want to cut power, without having to unplug the cable. Low-power usage Pi's like the Pi Zero and A+ can thus be powered and controlled from a single cable connected to your computer. Heavy-hitter Pi's like the Pi 2 and Pi 3 may draw too much power from a computer USB port, so check if your motherboard has a high-current USB port before trying.

Comes fully assembled and ready to go, plug into your Pi, and on Mac OS X install the driver - within 2 minutes and you'll be ready to go.

Works with any Raspberry Pi computer (Pi 1, 2, 3, Zero, etc)

Adding a character display to your project or computer has never been easier with the new Adafruit USB or TTL serial backpack! This custom-designed PCB can connect to the back of any 16x2 or 20x4 character LCD and does everything you could want: printing text, automatic scrolling, setting the backlight, adjusting contrast, making custom characters, turning on and off the cursor, etc. It can even handle our RGB backlight LCDs with full 8-bit PWM control of the backlight. That means you can change the background color to anything you want - red, green, blue, pink, white, purple yellow, teal, salmon, chartreuse, or just leave it off for a neutral background. On non-RGB backlights you'll be able to dim the backlight (it's on the same pin as the 'Red' LED)

Inside this backpack is an USB-capable AT90USB162 chip that listens for commands both a mini-B USB port and a TTL serial input wire. The USB interface shows up as a COM/serial port on Windows/Mac/Linux. The backpack will automatically select data from whichever input is being used. For the USB connection, it will work at any baud rate. For the TTL connection, the default baud rate is 9600 but you can send it a command to set the baud rate to 2400, 4800, 9600, 19200, 28800, or 57600 baud. (The baud rate is flashed on the LCD during powerup). Any customizations such as baud rate, backlight color, brightness, splash screen, etc. are stored permanently EEPROM.The command interface is compatible with the popular "Matrix Orbital" specifications so this backpack will work perfectly with computer applications or libraries that are expecting a "Matrix" LCD such as "LCD Smartie". We added a few extra commands for the RGB backlight and setting the LCD size. If you don't want to use the commands, you can just start sending ASCII to the LCD and it will magically appear as typed.

Does not include an LCD module! You'll need to pick out an LCD from the shop and solder it on the back.

Add lots of touch sensors to your next microcontroller project with this easy-to-use 8-channel capacitive touch sensor breakout board, starring the CAP1188. This chip can handle up to 8 individual touch pads, and has a very nice feature that makes it stand out for us: it will light up the 8 onboard LEDs when the matching touch sensor fires to help you debug your sensor setup.The CAP1188 has support for both I2C and SPI, so it easy to use with any microcontroller. If you are using I2C, you can select one of 5 addresses, for a total of 40 capacitive touch pads on one I2C 2-wire bus. Using this chip is a lot easier than doing the capacitive sensing with analog inputs: it handles all the filtering for you and can be configured for more/less sensitivity.Comes with a fully assembled board, and a stick of 0.1" header so you can plug it into a breadboard. For contacts, we suggest using copper foil, then solder a wire that connects from the foil pad to the breakout.Getting started is a breeze with our Arduino library and tutorial. You'll be up and running in a few minutes, and if you are using another microcontroller, its easy to port our code.

CAP1188 - 8-Key Capacitive Touch Sensor Breakout - I2C or SPI (1:35)

This is a breakout board for Freescale’s MPR121QR2. The MPR121 is a capacitive touch sensor controller driven by an I2C interface. The chip can control up to twelve individual electrodes, as well as a simulated thirteenth electrode. The MPR121 also features eight LED driving pins. When these pins are not configured as electrodes, they may be used to drive LEDs.

There a four jumpers on the bottom of the board, all of which are set (closed) by default. An address jumper ties the ADD pin to ground, meaning the default I2C address of the chip will be 0x5A. If you need to change the address of the chip (by shorting ADD to a different pin), make sure you open the jumper first. Jumpers also connect SDA, SCL and the interrupt pin to 10k pull-up resistors. If you don’t require the pull-up resistors you can open the jumpers by cutting the trace connecting them.

There is no regulation on the board, so the voltage supplied should be between 2.5 and 3.6VDC. The VREG pin is connected through a 0.1uF capacitor to ground, which means, unless you modify the board, you can’t operate the MPR121 in low-supply voltage mode (1.71-2.75VDC).

This is a board designed for opto-isolation. This board is helpful for connecting digital systems (like a 5V microcontroller) to a high-voltage or noisy system. This board electrically isolates a controller from the high-power system by use of an opto-isolator IC. This IC has two LEDs and two photodiodes built-in. This allows the low-voltage side to control a high voltage side.

We often use this board to allow a microcontroller control servos or other motors that use a higher voltage than the TTL logic on the (3.3V or 5V) micro, and may cause electromagnetic interferance with our system as the motors turn on and off. This board will isolate the systems, creating a type of electrical noise barrier between devices.

This breakout board uses the ILD213T optoisolator and discrete transistors to correct the logic. Comes with two channels. Great for use in noisy circuits where signal lines require electrical isolation.

A normal LED opto-isolator will invert the logic of a signal. We threw some transistors on this compact board to correct the inversion. What you put into the IN pins, will be replicated on the the OUT pins, but at the higher voltage (HV).

This breakout board is the simplest way to create a project with a single "momentary" capacitive touch sensor. No microcontroller is required here - just power with 1.8 to 5.5VDC and touch the pad to activate the sensor.When a capacitive load is detected (e.g. a person touches the sensor-pad area) the red LED lights up and the output pin goes high. You can also solder a wire to the middle pad and create your own capacitive pad if the built-in one isn't suited to your project.If you want to save power, the LED can be disconnected from the output pin (cut the trace between the jumper marked as such). We designed this breakout to have the more-responsive "fast mode" which draws about 0.5mA. If you need ultra-low (~50uA) power usage, the mode jumper can be cut on one side & soldered closed on the other to fix it into that mode. Check the datasheet for specific power usage measurements.Comes with a fully assembled board, and a small stick of 0.1" header so you can solder and plug it into a breadboard. For additional contacts, we suggest using copper foil, then solder a wire that connects from the foil pad to the breakout.The datasheet has many details on sensitivity, power usage, etc.

Standalone Momentary Capacitive Touch Sensor Breakout (11:10)

This breakout board is the simplest way to create a project with a single "toggle" capacitive touch sensor. No microcontroller is required here - just power with 1.8 to 5.5VDC and touch the pad to activate the sensor.This sensor is a toggle output type: touch-on then touch-off. That means that when a capacitive load is detected (e.g. a person touches the sensor-pad area) the red LED will alternate turning off and the output pin will go high or low, respectively. This sensor is good for a project where you want to activate something on the first touch, then deactivate it when touching again, like a switch. You can also solder a wire to the middle pad and create your own capacitive pad if the built-in one isn't suited to your project.If you want to save power, the LED can be disconnected from the output pin (cut the trace between the jumper marked as such). We designed this breakout to have infinite time-out. The chip does support having the sensor time-out, so for example, if something is turned on, it will eventually turn off on its own. If you'd like to use this mode, cut the TIMER jumper and then connect a resistor/capacitor to the TIME pin. Check the datasheet for how to calculate the TIME pin to match your desired timeout.Comes with a fully assembled board, and a small stick of 0.1" header so you can solder and plug it into a breadboard. For additional contacts, we suggest using copper foil, then solder a wire that connects from the foil pad to the breakout.The datasheet has many details on sensitivity, power usage, etc.

Standalone Toggle Capacitive Touch Sensor Breakout (11:10)