Shared Projects

I made this tiny board to use as an interface between an Orange Pi Plus (which can get quite hot) and a little fan. I’m also using as large a heatsink I could find & fit into the available space, which nicely also makes contact with the RAM chips.

The circuit I used is here.

The parts listed below I got form DigiKey, except for the RPi header socket, which also came from Amazon (as I neglected to include it in the DigiKey order). The best fit I could find on Amazon is an 18-pin stackable header socket.

• Q1: Infineon IRLML2502GTRPBF
• D1: Panasonic DB3X209K0L
• R1: Vishay Dale CRCW1206100KJNEA
• J2: JST B2B-XH-AM(LF)(SN)

GitHub repo

See https://github.com/urjaman/pnd-ser-6pin

Tapuino Normal Sized Board

2532 to 2732 socket board

Allows a 27C512 to be used as a PLA replacement in a C64. C1 is 68 pF

C64 Tape Emulator Tapuino

Fan Controller for Turris Omnia

TESTED / WORKING

Cost: $3.85 for three.

Description: This board is part of a USB programming adapter for the surface-mount (8-SOIC) version of the PICAXE 08M2 microcontroller. It’s basically a cheap replacement for the Revolution Education AXE-027 USB programming cable.

This board includes the standard PICAXE programming circuit consisting of 22k series and 10k pull-down resistors on the Serial In pin, as well as a 0.1uF decoupling capacitor for the PICAXE. The PICAXE is held in a zero insertion force (ZIF) socket (see Bill of Materials, below). Desolder the ZIF socket from its carrier board and resolder it to this board.

The six-pin header on this board connects to a generic FTDI FT232RL USB to RS-232 converter module. Search eBay for “FT232RL Module” and look for the red module with a jumper to select between 3.3V and 5V TTL (set the jumper to 5V). Bend the right-angle header pins on this module so they’re straight up from the board, solder this adapter onto the pins (ZIF socket facing up), then cut the pins flush.

Since many of the FT232RL modules sold on eBay use counterfeit chips, FTDI’s EEPROM programming utility, FT_PROG (here) is not a reliable way to invert the TX and RX lines as required to mimic the AXE-027 cable. Instead of relying on the ability to program the chip’s EEPROM, this board simply uses inverters comprised of two 2N7002 N-channel MOSFETs (the SOT-23-3 footprints on the board).

My Windows 10 computer recognized the serial converter module and loaded drivers automatically, but if you need drivers for an earlier version of Windows, Linux or MacOS, the FTDI Virtual COM Port drivers are available here.

Bill of Materials:

• 1 ea. FT232RL USB to RS-232 converter module (on eBay, here)
• 2 ea. 2N7002 N-channel MOSFET (SOT-23-3)
• 1 ea. 0.1uF ceramic capacitor (0603)
• 2 ea. 1k-ohm resistor (0603)
• 1 ea. 10k-ohm resistor (0603)
• 1 ea. 22k-ohm resistor (0603)
• 1 ea. 8-SOIC ZIF socket (on eBay, here)

Outputs overlay video for an Intellivision Master Component. Output is sent to pin 8 on the cartridge port.

Combination of low-power AK9753 2x2 IR Array as watchdog and AMG8833 8 x 8 IR Array for human presence and contextual activity detection. Intended to mount on back of an nRF52 development board.

Phoenix (Centuri) to JAMMA Adaptor.

Maker OE Network connector

2x2 IR array for human presence detection.

bias board

variable gain amplifier