A while ago we came across a website on infrared remote controls which suggested a simple way to view IR signals using an Oscilloscope. The idea is to use a standard IR Led mounted into a BNC/RCA plug using a spare channel making an Oscilloscope infrared receiver. So we set about ordering the connectors, which arrived in the post today. Another way of looking at this device is as a ‘poor-mans’ IR receiver, but if you have an Oscilloscope to plug it into then maybe you are not so poor after all.
Many electronics enthusiasts will be familiar with how Infrared receivers demodulate IR signals. In this post we show a visualisation of the time lag and distortion of the signals as they pass through the IR receiver for demodulation and noise filtering. Most DIY projects use the raw timings from the IR receiver to decode individual signals. However, not many will be aware that IR receivers can distort the signal timings by significant amounts. Fortunately, common IR decoders take this into account and compensate for timing distortions introduced by infrared demodulators / receivers.
Recently we have been helping several members on the Arduino forum to record and playback their remote control signals from their Air Conditioners. These signals are typically much longer than those of TVs or common media devices. The 2 most popular libraries for Arduino, IRremote & IRlib are excellent, but have some limitations which we have covered in a previous post. In this post we address one particular issue that is proving challenging to users.
Over the last few months we have been regular contributors to the Arduino and other forums, answering questions about Infrared remote control projects. It became apparent that beginners typically trip up on many common ‘pitfalls’. So we decided to list off our ‘Top 10’.
We have been intending to add support for LIRC into AnalysIR for a long time. Recently one of our enthusiastic users, working on his Raspberry PI, needed some help getting Air conditioner signals from his ‘Air Conditioner’ infrared remote control decoded. His preference was for a LIRC based approach as he already had this working for his TV via his RPi using a cool web based interface from his smart phone.
Dublin, Ireland – 31st January 2014. We are happy to announce the latest ‘New Year’ release of AnalysIR to all our backers & supporters. Since the completion of the crowd-funding campaign on Indiegogo we have added over 125 updates and enhancements to AnalysIR, with more to come.
Here is a screenshot showing the new automatic signal cleaning feature in AnalysIR. You will notice in channel 2 (yellow & red) where I have overlaid the recorded signal from CH1 (green) on top of the cleaned signal in CH2 (yellow). The green & red signal is the recorded signal & the yellow signal is the ‘cleaned’ signal.
Note: Use CTRL+, CTL-, or CTRL0 – to zoom in & out on most browsers The reason for the signal degradation in the first place is due to the way all IR receivers work. Typically, marks will be shorter and spaces will be longer. Also, weak IR signals will also alter the duration of marks/spaces.
Combined with AnalysIR’s sensitivity setting for decoding it is possible to rebuild a perfect signal from a really poor signal.
With this new ‘Bonus Feature’, we can export almost perfect signals from AnalysIR and re-import the exported signal to compare against the original recorded signal. This will be a great benefit when designing IR devices or circuits.
The news is that today AnalysIR was accepted into the Microsoft BizSpark programme, which will help us out in our development efforts on the MS platform along with lots of other goodies.
The Bonus feature is the addition of support for Importing of Global Caché commands in GC-100, iTach, GC-IRL & GC-IRE formats into AnalysIR. This was suggested by one of our backers & we hope to close the loop by supporting export as well (Time permitting).
An interesting point is that GC sells a learning device (like an RS-232 dongle) for importing IR signals and it costs circa $100 on Amazon. It looks like when we get the export feature working, AnalysIR with an Arduino will be able to a lot lot more than this $100 device.
So the list of formats now supported for import includes:
– IRremote – IRLib – Pronto CCF – Global Caché GC-100 – Global Caché iTach – Global Caché GC-IRL – Global Caché GC-IRE
and we may add a couple more in the initial release. We also hope to support export of these protocols from AnalysIR – time permitting. This means that you will have a generic device than can record & decode via the Arduino – plus convert to/from all these formats. Impressive!
Thanks to our backer who has a Global Caché device and is willing to test the AnalysIR export once it is available.
Use coupon code 10offanalysir during checkout to get 10% off purchases of AnalysIR software (Maker & Pro Editions only), for a limited time only. Also check out our newly released MakeIR modules & shieldsvia our webshop.