Arduino compatible AVR Development Board

Design Files

Shield for the Arduino Mega, supporting up to five servos (current monitored and powered separately), eight 3-pin IR sensors and eight 4-pin ultrasonic sensors

http://raphaelchang.com/#projects/bms

UNTESTED board to merge a 2.8 tft and a pi zero, with access to the gpio

Board v 2.0 Accessory feather board for Huzzah based networked temperature controller. https://github.com/cj8scrambler/eagle/tree/master/HUZZAH_TEMP_CONTROL

Mini-Board V1Atmel Mega-8 through 328

This board allows for easy programming of an Atmel AVR in the Mega-8, Mega-168, Mega-328 etc series. The board has a 10-pin ISP header along with power indication LED and a place to install an external 10 to 20 MHz resonator. The board will plug into a standard breadboard.

If using a 5v supply, the resistor should be 220 ohms, if using 3.3v supply, then use a 100 ohm resistor.

USB Interruptor

This simple board plugs inline with a USB cable. It always passes the 5V power and normally passes the USB data signals. But when you press the button, the signals are momentarily disconnected.

Why would anyone want or need such a things? Well, for the last few months I’ve been developing a USB Host Library for powerful but complex EHCI USB port in Teensy 3.6. After several false starts and re-reading the USB 2.0 and EHCI 1.0 specs and datasheet over and over (did I mention this 480 Mbit/sec USB host port is powerful but really complex), it’s finally starting to come together.

Now I’m at the stage where it’s time to begin work on code to handle USB disconnect events. When you unplug the cable, the ECHI work queues need to be removed, periodic schedule bandwidth allocation/planning needs to be undone, memory needs to be freed (hopefully it’s all findable from linked lists), hub/port status needs to be updated, and probably a ton of other stuff needs to happen that I haven’t even considered yet…

Reaching over to physically unplug the USB cable gets old quickly! Really, really old, both hands off my keyboard… right when trying to focus. With 12 Mbit/sec USB ordinary switches can usually work, but this is 480 Mbit/sec and I’m already running it through a USB protocol analyzer and a few cables plugged in tandem, leaving not much signal quality margin left. So I made this handy little board with a proper USB 2.0 high speed mux chip. The control signal is just 3.3V logic, so I might even wire it up to something to automate the process.

Admittedly, not many people develop USB host drivers and software stacks (it’s turning out to be probably the toughest coding I’ve ever done), so this little board might not have really wide applications. But here’s all the details anyway. ;-)

Update: check out this similar board, using slightly different parts.

Parts Placement

Bill Of Materials

1   Resistor, 10K, 805              RHM10.0KCHCT-ND
1   Capacitor, 0.1uF, 805           478-1395-1-ND
3   Capacitor, 1uF, 805             587-1281-1-ND
1   Diode, Schottky, B120           B120-E3/5ATGICT-ND
1   MCP1700 3.3V regulator          MCP1700T3302ETTCT-ND
1   FSUSB30 USB Mux Switch          FSUSB30MUXCT-ND
1   USB Connector, Mini-B           609-4701-1-ND
1   USB Connector, Std A            ED90065-ND
1   Pushbutton                      P8016S-ND

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

A programming adapter for ATtiny13 and similar chips.

Arduino Uno shield for 16x32 RGB LED Panel with external push button and optocoupler for triggering additional switch.

Minimal HTU21,SHT21,SI7021 breakout

small prototype board using IMM-NR52832 module

Dual TX Power Adapter for RC Transmitters

Pressure Sensor MPX5xxx I2C 16bit ADC ADS1100 - Arduino /Raspberry Drucksensor

*Note this version updates version 2017/001-015 with a fix for the I2C disconnect jumper.

This is a LEGO Minifigure sized development board using an Atmel SAMD21E 32-Bit ARM chip. I basically followed the recommended layout/setup from the SAMD21 spec sheets.

Included on Mini SAM is a WS2812B LED pad connected to PIN 27, a 0603 LED connected to PIN 15, a reset button with support components per the datasheet, and a generic button that is active HIGH on PIN 28. The 0603 LED is connected in series with a 1Kohm resistor, part of R1, and care should be taken when selecting an 0603 LED such that at a supply of 3.3V, no more than 5mA is required.

Programming port is a standard10-pin SWD for ARM based processors, which is a 2x5 1.27mm pitch connector. The SWD line is pulled up with a 1Kohm resistor, part of R1. In the BOM, either purchase the 2x5 straight pin connector OR the 2x5 POGO connector and do not populate board.

The SDA/SCL pins are pulled high with 4.7KOhm resistors, R2, per SDA/SCL recommendations.

The voltage regulator is an AP2112K-3.3V which is rated at 600mA at 3.3V. Plenty of current for the SAMD21E and a few other accessories such as the WS2812B.

This version has SMT layout for two single row 2.54mm pitch headers on the back. It is designed to be protoboard friendly and when populated the headers are the same width as a DIL package (7.62mm or .3") and span the center of a protoboard.

PINs 27 and 28 are not connected to headers - due to lack of space - but instead have two pads near the bottom of the board. PIN 27 is connected to the on-board WS2812B. PIN 28 is connected to the on-board BUTTON.

The Analog Reference (PIN AREF) - has a pair of decoupling/filtering capacitors.

The micro-USB connector has an RC filter between the case/shield of the connector and GND. If R6 and C13 are left un-populated the case/shield is an open circuit - which is the next best option. Also included is space for a PRTR5V0U2X ESD protection circuit on USB Data lines. This may also be left un-populated and USB will function normally.

I have put together a sample BOM via Mouser.com which I’m including here. It can be used as a reference. Optional, but highly recommended components: SW2812B 3535 LED, 0603 LED, SW2 (BUTTON), R4, R5, R6, C13, and PRTR5V0U2X. R1 is for the 0603 LED and SWCLK - If not populating the 0603 LED this may be left un-populated as well and programming via SWD should still work as I’ve seen other boards without the 1Kohm resistor on SWCLK. R2 is the 4.7Kohm pull-up resistor pair for SDA/SCL. Many breakout boards using chips that run off SDA/SCL typically come with the 4.7Kohm pull-up resistor pair included - as such it may not be needed on Mini SAM - but it is included for ease of future components. Please review the schematic for additional details and be aware that the BOM on Mouser.com may be out of date. The SW2812B is not in the Mouser BOM - due to lack of parts.

Mouser BOM

I would suggest not purchasing the 2.54mm pitch SMT male headers from Mouser, as you can find this much cheaper elsewhere. The best I could find on Mouser is (2) 5-Pin and (2) 6-Pin headers. Mini SAM requires (2) 11-PIN headers. I suggest buying breakaway headers in 25-50 PIN lengths.

Arduino FIRMWARE/BOOTLOADER is complete, but I’m still testing all functions. So far all PINs work in digital setup and all analog PINs work accordingly. ANALOG and special function pins (MOSI, SDA, SCK, etc) can be accessed in Arduino by their name.

Please check my Github for the latest design files and bootloade/firmware.

More details can be found on Github

Amiga Floppy Reader

3.5mm Jack Breadboard Adapter

For an ESP8266, with programming connectors and switches and supporting Deep Sleep mode. Designed to connect to a BME280 Temp/Humidity/Barometer by wire using I2C.

BOM

• C1 1uF 1206 SMD
• C2 10uF 1206 SMD
• P1 JST XH B04B 4 Pin Straight
• P2 2 Pin Header Straight
• P3 6 Pin Header Straight
• P4 JST XH B02B 2 Pin Straight
• R1 0R 1206 SMD 1%
• R2 4.7K 1206 SMD 1%
• R3 4.7K 1206 SMD 1%
• R6 4.7K 1206 SMD 1%
• SW1 ALPS SKQGAFE010 SMD Tactile NO
• SW2 ALPS SKQGAFE010 SMD Tactile NO
• U1 ESP-12F
• U2 MCP1700T-3302E/TT SOT-23

The board design has been updated since this version:

• I missed off a pull up resistor on CH_PD (but can easily be tacked on the back of the board if you use this version)
• redesigned the layout so my fingers could get at the switches ;-)
• Added a switch to bypass the regulator so the circuit could be used either with 3.2v LifePO4, or 3.7v Li-ion batteries

All updates on my github repo here: https://github.com/theopensourcerer/esp8266_envmonitor

(UNTESTED)

ESP8266-12 based temperature sensor. Using a waterproof DS18B20 1-wire sensor. Board powered from 12v DC using a switching regulator (Murata OKI 78SR)

• All resistors are 1206 SMD 4.7k
• All capacitors are 1206 10uF ceramic
• Main connectors are JST XH style.
• Tactile Switches are ALPS SKQGAFE010 SMD Tactile NO
• Switching Regulator is OKI-78SR-3.3/1.5-W36-C

Project details all on Github: https://github.com/theopensourcerer/esp8266-external-temp-sensor

servo controller for waveguide switch