Mini 1275GT reassembly and electrolysis of rusty parts!

Here's a few pictures of what's been absorbing most of my time lately....

It doesn't look like much, but there's all new brake lines fitted, lots of parts cleaned and painted and reunited with the car!

To clean up a lot of the metal parts, I've taken to electrolysis...

This involves making a mixture of about 10% ordinary washing soda (you can get this from Sainsbury's in the UK, £1.20 in my local store for a 1kg bag) and tap water.

You'll need a nice clean piece of ordinary mild steel (Don't use stainless). I used a plate, you can see it in the centre of the tank. And you'll need a power supply (I used my adjustable bench supply)

Connect the clean steel to the positive terminal, this becomes our sacrificial anode. You'll probably realise from the name, that this isn't a piece of steel you'll want to use again....



Attach the rusty part to the negative pole, and drop it in the tank.... Keep a small distance between the part and the steel plate.

Switch the supply on, and adjust the voltage until a bit of current flows. Small bubbles will rise to the surface. I found good results with about an amp of current flowing.

You'll want to do this in a very well ventilated area, as the bubbles are hydrogen and oxygen, and PLEASE switch off the supply before adding or removing things from the tank, a spark could ignite the gas.....

After a new hours remove your once rusty part.

You'll need to clean off the solution, dry it and paint it to prevent it rusting rapidly.

What's happened to the rust? It's on the anode ....

This is after just a couple of days of use... you can clean it up with a wire brush or grinder and it'll go again :)

Simple Arduino Thermostat with MAX7219 Display and DS18B20 sensor

Just shows how these jobs snowball....

James had seen Oto's dehumidifer controller, and said "I need something to monitor and control the temperature of my honey warming cabinet" (it's a beekeeping thing!)

A simple thermostat, with a nice clear LED display, and adjustable set point was born ....

You'll see the code, and most of the schematic is very close to the dehumidifier controller, so I'll not dwell too much on that.. the main difference is the use of the MAX7219 7 segment display, previously used on the GPS clock, and the DS18B20 temperature sensor, which I'd previously used in the pond pump controller.

Here's the code:
/ /* James' Thermostat controller Copyright A.G.Doswell May 2017 License: The MIT License (See full license at the bottom of this file) Visit Andydoz.blogspot.com for description and circuit. */ #include <OneWire.h> // from http://playground.arduino.cc/Learning/OneWire #include <DallasTemperature.h> // from http://www.hacktronics.com/code/DallasTemperature.zip. When adding this to your IDE, ensure the .h and .cpp files are in the top directory of the library. #include <EEPROM.h> #include "LedControl.h" LedControl lc = LedControl(12, 11, 10, 1); //Tells LedControl where our hardware is connected. #define ONE_WIRE_BUS 8 // Data wire from temp sensor is plugged into pin 8 on the Arduino OneWire oneWire(ONE_WIRE_BUS); // Setup a oneWire instance to communicate with any OneWire devices DallasTemperature sensors(&oneWire); // Pass our oneWire reference to Dallas Temperature. // define constants & global variables const int rlyPin = 3; //defines pin the relay is connected to. relay is active low int Timer = 0; //timer is off to start const int upPin = 6; const int downPin = 9; int setPoint; // temperature set point int setPointTimer = 0; // timer to prevent setPointAdjust loop from returning to main loop int setPointEEPROM; // Set point value stored in EEPROM int tempC; // Temperature in degrees C boolean heaterOn; // true if heater on void setup() { lc.shutdown(0, false); // Wake up the MAX 72xx controller lc.setIntensity(0, 8); // Set the display brightness lc.clearDisplay(0); //Clear the display pinMode (rlyPin, OUTPUT); // sets our relay pin digitalWrite (rlyPin, LOW); // sets the relay off for default condition. pinMode (upPin, INPUT_PULLUP); // sets up control pin pinMode (downPin, INPUT_PULLUP); // sets down control pin setPoint = EEPROM.read(0); // get the stored set point sensors.begin(); // start up the Dallas temperature sensors } void loop() { setPointAdjust (); // calls the adjust set point routine sensors.requestTemperatures(); // Request temperature tempC = sensors.getTempCByIndex(0); // set the temperature in degrees C from the first sensor in line, rather than by address. updateDisplay (); // update the display if (tempC >= (setPoint)) { // if the temperature is greater than or at the setpoint, switch the heater off digitalWrite (rlyPin, LOW); // switch heater off heaterOn = false;// set the flag (used in updateDisplay) } else { digitalWrite (rlyPin, HIGH);// switch heater on heaterOn = true; } } void setPointAdjust () { // check the up down controls, and adjust the set point as required if (digitalRead (upPin) == false) { // if the up switch is pressed, increment the set point setPoint++; if (setPoint >= 101) { // limit the set point to 100 degrees setPoint = 100; } updateDisplay (); delay (200); // sensible delay to stop the set point being incremented too fast setPointTimer = 100; // delay number of loops before returning to main loop } if (digitalRead (downPin) == false) { // same as above for decrement setPoint--; if (setPoint <= 0 ) { // minimum set point is 1 degree setPoint = 1; } updateDisplay (); delay (200); setPointTimer = 100; } if (setPointTimer == 0) { // delay return to loop for 100 operations, then write to EEPROM and return to main loop setPointEEPROM = EEPROM.read(0); if (setPointEEPROM != setPoint) { // if the value changed, write new value to the EEPROM EEPROM.write(0, setPoint); } return; } setPointTimer --; delay (50); setPointAdjust (); // loop back round unit the setPointTimer has expired } void updateDisplay () { // update the LED display int tempUnit = (tempC % 10); // units of temp int tempTen = (tempC / 10) % 10; // tens of temp int setPointUnit = (setPoint % 10); // units of setpoint int setPointTen = (setPoint / 10) % 10; // tens of setpoint lc.setDigit (0, 7, tempTen, false); // write info to display lc.setDigit (0, 6, tempUnit, false); lc.setRow(0, 5, B01100011); //degree symbol lc.setRow(0, 4, B01001110); // display C lc.setDigit (0, 3, setPointTen, false); lc.setDigit (0, 2, setPointUnit, false); lc.setRow(0, 0, B01001110); // display C if (heaterOn == true) { // set decimal place on if the heater is on, on last display. lc.setRow(0, 1, B11100011); // degree symbol with decimal place set } else { lc.setRow(0, 1, B01100011); //degree symbol } } /* Copyright (c) 2017 Andrew Doswell Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute and sublicense copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions: The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software. Any commercial use is prohibited without prior arrangement. THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHOR(S) OR COPYRIGHT HOLDER(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */




Ryan built up a nice enclosure....

















... and, in a stroke of genius, added a strip of red PVC insulating tape to improve the contrast of the display!