HD44780 4-bit Parallel to 3x Serial (I2C, UART, SPI) adapter.

FET/BJT Mic Preamp (v1.4 with ground planes)

FET/BJT mic preamp (V1.4)

Control panel for mic preamp (square, fits in 1RU)

BLF flashlight driver, 20 mm, DD+m

Features

• 20 mm direct drive + 350 mA regulator LED driver
• No OTC - Intended for e-switch, memory-decay or no-memory firmware.
• R5 to eliminate unintentional Vcc boosting during PWM.
• R3, R4 for stable drive of FET.
• Oversized heat plane for the 7135 with good thermal link to the ground ring.
• Generous 0603 pad sizes that will accept 0805 parts as well.
• Universal package size for MCU. Tiny13-85 fits.

Revision changes

• New

Suggested parts list

• U1: Atmel Attiny25, SSU or SSN package
• U2: 7135 350 mA LED driver
• Q1: Vishay SiR800DP
• C1: 10 uF, X5R or better, 0805
• D1: Schottky diode, 200 mA 20 V or better, 0805 or SOD323
• R1: 22 / 330 kohm, 1%, 0603 (R1, R2 larger values for e-switch lights)
• R2: 4.7 / 100 kohm, 1%, 0603
• R3: 100 kohm, 5%, 0603
• R4: 47 ohm, 5%, 0603
• R5: 4.7 ohm, 5%, 0603

Moved mic up a bit to minimize button interference.

eMMC Test Project for CPC2.0 For information see my blog at https://intelligenttoasters.blog/2017/01/29/retro-cpc-dongle-part-18/

The Sunrise Alarm Clock project is a silent light-based alarm. Using an LED light strip or board, this project will simulate the rising sun to wake up the user with light.

This board interfaces with an Adafruit DS3231 breakout board and a 7 segment display breakout board.

In the current revision, there is no method for writing the time to the DS3231 module. Use female header to allow the removal of the module. Use a Raspberry Pi or equivalent to set the time over NTP.

Major Components

• Atmega328P-AU

• Adafruit DS3231 Breakout

• Adafruit Red 7-segment LED Breakout

• LD1086BDTTR 5-volt linear regulator

• PSMN022-30BL N-channel mosfet to switch LED light strip

LiPo-battery-powered sensor tile with multiple sensors, 1 MB SPI flash, and BLE managed by a STM32L432 host.

A very simple IN-12B Nixie breakout board

Parts needed

• 11 MMBTA42 transistors
• 12 30kOhm 0603 (Imperial) SMD resistors
• 12 1mm socket pins (can be found on Ebay)
• Some standard header pins (2 for GND, 2 for HV-IN, 11 for inputs)

Usage

• Provide ~180V between HV-IN and GND
• turn on any digit with a 3.3V or 5V logic input on corresponding pin

Known issues

• the additional GND and HV-IN header pins (for daisy chaining) may be blocked by the Nixie itself

Source files can be found on my Github. Feel free to submit PRs !

Resistor board for alarm systems

Analog rssi for EZUHF. Turns the EZUHF PWM signal into a 0 to 3V analog output. Now tested and working nicely

PURPOSE

Adapt the odd pad pitch of the RFM69CW or RFM69HCW to a breadboard friendly spacing and lay the pins out so that they match with the ATMega 328p-DIP ideally.

SIZE & COST

18.64mm x 21.16mm = $1.02 per board

DISCUSSION

An extremely small breakout board for adapting the odd pad pitch of the RFM69CW radio to breadboard friendly pin spacing. In particular some care was taken to place pins such that they work perfectly with an ATMega 328p-DIP (the chip in Arduinos). Used in this way, the board should span pins 15 through 22 on the 328p so as to match up MISO, MOSI, SS, SCK, VCC, and GND. The only other pin needed in some cirumstances is DIO0 which is mated up to PB1.

Source at github

This is a breadboard adapter for Digitabulum-r2. All signals are broken out and labeled.

Intended usage

This project has two purposes:

1) To be used as-is as a breadboard adapter and development tool.

2) To be used as a template for a custom Digitabulum backplane.

Features

• JTAG breakout
• 2.54 headers

Small i2c 3 channel LED driver. Powered by a PCA9633. Third Revision.