Optical Heart rate Monitor

just a test DO NOT ORDER EVER!!!!!!!!!1

PT8211 Audio Shield

PT8211 is an inexpensive 16 bit stereo DAC.

This small breakout board connects the PT8211 to Teensy 3.2, Teensy 3.5 or Teensy 3.6.

Detailed soldering steps are shown on the PJRC product page, where this PCB is sold as part of a DIY soldering kit. Of course, you can also get the bare PCB here on OSH Park if you like.

Here is the assembly with the PT8211 on a purple OSH Park Edition Teensy 3.2.

Bill Of Materials

1   PT8211 chip                Ebay merchants
1   Audio connector, 3.5mm     CP1-3525N-ND
1   10 ohm resistor            10EBK-ND
3   47 uF capacitor            493-15997-ND
1   0.1 uF capacitor           BC1084CT-ND

How to use Digikey’s website to find alternate parts when any of these aren’t in stock.

Almost any 5mm diameter aluminum electrolytic capacitor with 2mm lead spacing can work. While 47uF is recommended, you can see in the photos I built the first prototype using only 10uF (because they were in my spare parts drawer). Either works fine.

The PT8211 chip is very inexpensive, sold by many shady Ebay merchants from Hong Kong at very low prices. There doesn’t seem to be any sure way to buy this part, but just searching for “PT8211” on Ebay brings up many sellers.

Software Support

PT8211 is supported by the Teensy Audio Library.

You can simply drag the PT8211 onto the Design Tool canvas and connect it into your audio system, and of course click “Export” to generate the Arduino code.

It’s also possible to edit any of the audio library examples, which are designed for the Teensy Audio Shield. With Teensy selected in Tools > Boards, just click Arduino’s File > Examples > Audio menu to find dozens of examples. To convert these, just find AudioOutputI2S in the code and change it to AudioOutputPT8211.

Also delete any AudioControlSGTL5000 objects and code using them. The PT8211 is a very simple chip without any configurable parameters. You just send it digital audio and it turns the data into analog signals. Simple!

PT8211 Signals

PT2811 Datasheet

Signal     Teensy Pin     PT8211 Pin
------     ----------     ----------
 BCK            9              1
 DIN           22              3
 WS            23              2
 +3.3V       3.3V              5
 GND          GND              4

TC Electronics Level Pilot Replacement Board

audio part of a 4 output headphone distribution amplifier

Contracted board design for Kule Tech - design employers a smart thermometer for detecting milk pasteurization levels.

Part of the echOmods project, with a focus on the motherboard.

Chip whisperer Differential Probe

Weather station

6 USB Charging Ports

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Low Noise Amplifier for SDR Radio ADS-B reception Ver. 3.2 with 1090MHz ceramic-coaxial-resonator based bandpass filter, for aluminum case 25x25x80mm mount and 5 volt bias power. This board uses mostly the same components as the Ver 2.3 board linked below, but places the bandpass filter before the LNA and also requires 5VDC external bias power thru the output SMA connector. NOT-TESTED https://www.barbouri.com/2017/03/12/low-noise-amplifier-for-sdr-radio-ads-b-ver-2-3-with-1090mhz-ceramic-filter/

MCPCB substitute for Cree XLamp. Intended to work with thermal glue or epoxy. Common-anode/cathode configuration.

MCPCB substitute for Cree XLamp. Intended to work with thermal glue or epoxy. Individual connections.

MCPCB substitute for Cree XLamp. Intended to work with thermal glue or epoxy. 4-series configuration. With 0603 1- and 2-LED bypass jumpers.