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I have a project where I am using a PICAXE controller to control water heating at solar thermal hot water systems. Things are going well and I am using the controller for monitoring as well - by outputting data every few mins to an Excel spreadsheet. I have several installations and I use...

There is a photo limit of 2. I've added two here, one is the gas lighter device I mentioned and the other shows the OLED display. Its the lower of the 2 display boxes.

I started a Thread on 9 Apr 2013 “EMC Testing” before attempting to get my control circuit based on a 20X2 through the UK EMC tests. People gave me helpful time and advice and I’m reporting back here after completion of the testing. This is the same material as in the main Forum thread...

Immunity - Cables to DS18B20 probes and OLED Any cables longer than 3m needed testing, which confirmed there were problems with both the leads to the temperature probes and the OLED. Noise added to the leads with a heavy coil thingy knocked out the signals. The book recommended to me by this...

Emissions and pwm The first tests showed the motor was associated with noisy radiated emissions above the permitted limit. · The problem only arose when the power to the pump was being reduced using pwmout. · Using a linear power supply rather than a switched mode power supply actually made...

I started a Thread on 9 Apr 2013 “EMC Testing” before attempting to get my control circuit based on a 20X2 through the UK EMC tests. People gave me helpful time and advice and I’m reporting back here after completion of the testing. Before I get going, I’ve tried to see if there has been any...

I posted a few weeks ago about Electromagnetic Compatibility (EMC) testing of my PICAXE based (potential) product. There were several issues highlighted that need addressing. With one at least I think I need help……… It’s the communication between the controller and the OLED display. The lead...

I used 2-gang patress boxes from Screwfix, about £1, and thier blanking plates, about 50p, or so and so I could afford several failures on the window size and finish. I used a router not a Dremel. The OLED is glued on the back with adhesive silicone (like clear bathroom sealant but better grab...

The circuit Thanks again for all the comments. Here is my circuit, somewhat simplified (eg no download cable and only one of multiple sensors shown). Some notes: The control circuit PCB is currently in a plastic box, but a metal one won’t be much more expensive. The pump has a brushless...

I am developing a solar thermal (hot water) system with a control system using the PICAXE 20X2 chip. I’ve done plenty of user trials and now I’m gearing up to commercialise. To get my CE marking I believe the system needs to pass some EMC tests – so that we know it won’t be upset by other...

2 more photos to show it connected up to LCD etc Martin - its a Kosher techsupplies DS1307. The DS18B20's are from China and they've performed well so far in my other projects.

Photo of circuit Here we go. As I said I've now added more. The circuit sketch is updated here, additions are in red and the "TS" connections are the signals to external temperature probes, DS18B20's. The diode can be seen. And here is an annotated photo. I will post again with 2...

Folks I can't see where I'm going wrong with my DS1307 project. The clock reports time very slow - about 40 secs reported for every actual min passed. Here is a sketch of the circuit: And here is the code. It's a 20X2 chip. I used the wizard under 'AXE110 Datalogger' to set the clock then...

Thanks all for your help on this and the answer is clear. Cheers Boriz for forthright comments. Perhaps the PICAXE people might respond to this point you make because the 18M2 High Power Board seems to omit the resistor in question. Here is the circuit from the relevant datasheet. Boriz...

I need to decide whether to use REG001 78L05 Fixed Voltage Regulators or the considerably more expensive REG005 5V voltage regulators which the tech-supplies website say are "low dropout voltage regulator (higher quality than 78L05)." I want a fully reliable circuit but don't want to waste...

Here it is. My work on the Project board is shown in orange. The FET circuit I copied from my power board and linked across is in black because I don't know how to change its colour. The supply is a 12V switched-power thingy - effectively a plug in phone charger

I've been struggling with getting reliable readings from my DS18B20 sensors when I also have hpwm code. I am running a variable speed pump based on temperature readings. I see from the manuals that the readtemp12 commands can interact with hpwm due to internal frequency changes and the manual...

Here are the photos of my soldering equipment and the LCD. I think I need a link to a good website on PCB soldering as well as better solder. In fact a YouTube clip would be just great. I think I can only upload 2 photos per post, so I'll post a couple more in a minute or two. I used highest...

I've bought about 15 of the budget LCD and OLED kits and I can't make them up consistently. I've had 1 or 2 in the past that just never worked and yesterday I made 2 and neither work. I've checked for shorts between the header pins and my other soldering points. I also checked that the pin...