This article documents the RF electronic part of a HF current probe project.
The AD8310 module was bought on eBay for about $10. Continue reading AD8310 module for HF current probe
Category: Electronics
CNC6040 router project – cut of enclosure for grbl_ESP32
One of the intended applications of the CNC router is to cut openings in metal and plastic enclosure boxes boxes for things like LCD displays, tactile button switches, connectors etc.
First ‘production’ job was a box to contain the grbl_ESP32 gcode interpreter, part of the CNC router if you like.
This module is the grbl_ESP32 box in the block diagram above. Continue reading CNC6040 router project – cut of enclosure for grbl_ESP32
CNC6040 router project – test cut of a Jiffy box
One of the intended applications of the CNC router is to cut openings in Jiffy boxes for things like LCD displays, tactile button switches, connectors etc.
After a lot of testing, it came time to try it on some target work.
Above is a scrap Jiffy box and the milling job is to cut holes for three pushbuttons (tactile momentary switches on a veroboard base with 10mm caps) and the holes for M3 screws and pillars. Continue reading CNC6040 router project – test cut of a Jiffy box
CNC6040 router project – spindle speed linearisation – using new grbl_ESP32 feature
A known issue with the common CNC6040 router and similar devices is very poor calibration / linearity of the spindle motor response to gcode Sx commands.
Above is the system block diagram. The grbl_ESP32 gcode interpeter processes a gcode S (speed) command, converting it to a variable duty cycle PWM waveform on parallel port pin 1. Continue reading CNC6040 router project – spindle speed linearisation – using new grbl_ESP32 feature
CNC6040 router project – spindle speed linearisation
A known issue with the common CNC6040 router and similar devices is very poor calibration / linearity of the spindle motor response to gcode Sx commands.
Above is the system block diagram. The grbl_ESP32 gcode interpeter processes a gcode S (speed) command, converting it to a variable duty cycle PWM waveform on parallel port pin 1. Continue reading CNC6040 router project – spindle speed linearisation
OpenLog for TinyTrak – inline DE9 adapter
OpenLog for TinyTrak described a data logger for APRS NMEA data.
This article shows an innovative inline adapter for adding an Openlog to an existing APRS installation where the GPS is powered with 5V via the DE9 connector.
Above, the adapter comprises a DE9 male and DE9 female connector cabled together as a through connection, and the Openlog is wired into one of the backshells, wrapped in heat shrink tube, and velcro’d to the backshell. Continue reading OpenLog for TinyTrak – inline DE9 adapter
Designing with binocular ferrite cores – published Al values
Designing with ferrite binocular cores can be frustrating as there are different formats in which data is provided, and data for different mixes on the same dimensioned cores appear inconsistent.
There are several source of the Al parameter for some common cores, often from resellers rather than manufacturers. Continue reading Designing with binocular ferrite cores – published Al values
Designing with binocular ferrite cores – Σ(A/l)
Designing with ferrite binocular cores can be frustrating as there are different formats in which data is provided, and data for different mixes on the same dimensioned cores appear inconsistent.
#61 mix
This article documents calculated geometry Σ(A/l) derived for a number of Fair-rite cores from their specified Al (at µi). Continue reading Designing with binocular ferrite cores – Σ(A/l)
Basic programming jig for STC15F104E and STC15F204E chips #3
The STC15Fx chips use a simple TTL/CMOS async programming interface that is suited to the common USB-RS232(TTL) adapters. This article describes a low cost programmer that also allows the programming application to Vcc (so initiating the boot loader automatically).
Above is the programmer ($2.50 on eBay) and a small adapter that plugs into the top row of the 2×5 header on the programmer.
DIP-28 are located carefully so that the pins 10-18 are in the socket, the same connections are used for both chip sizes for STC15F104E and STC15F204E. Continue reading Basic programming jig for STC15F104E and STC15F204E chips #3
XH plug savers on the STC U8W & U8 programmer
STC produce the U8W & U8 programmers for a range of their chips.
U8W
The thing has a JST 7way XH socket provided for an ISP connection to a target board. It is accessed through a cutout in the acrylic housing, but the cutout is no bigger than the shoulder on an XH plug and one cannot get tools in beside it to pry the plug out without pulling on the wires.
The good thing is that there is an inexpensive “XH plug saver” sold to the RC market, it provides a means of getting a convenient grip on the plug without pulling on the wires.
First step is to mill out the case opening to accommodate the XH plug saver.
Next, add the XH plug saver to the XH plug, and it all works. Continue reading XH plug savers on the STC U8W & U8 programmer