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Topic: USB IR Toy update (Read 17931 times) previous topic - next topic

Re: USB IR Toy update

Reply #15
Absolutely, thanks.

*RC2 to header
* IR Led driver to header
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Re: USB IR Toy update

Reply #16
Is there any disadvantage to flipping the programming header around 180 degrees?  That would put the AUX pin over nothing, which is guaranteed not to conflict with any programmer's circuit.

Re: USB IR Toy update

Reply #17
[quote author="ian"]
Absolutely, thanks.

*RC2 to header
* IR Led driver to header
[/quote]

Thanks that should be useful for driving other IR LED outputs.

I went back and looked at the Nirvis Slink-e to see how it had 8 IR outputs with a PIC 16C67.  It looks like it is using a single PWM line but driving the output enable of a 74LS374.   I think it would be possible to do something similar (with less lines) using the new output header.

Re: USB IR Toy update

Reply #18
[quote author="rct"]I went back and looked at the Nirvis Slink-e to see how it had 8 IR outputs with a PIC 16C67.  It looks like it is using a single PWM line but driving the output enable of a 74LS374.   I think it would be possible to do something similar (with less lines) using the new output header.[/quote]
Yes, the new output header would allow experimentation along these lines.

As an aside, the 74LS374 only handles 24 mA (2.6 mA when hi), so another chip is needed to boost the current.  With the right transistor, you could take the single line from the IR Toy header and directly drive 8 IR LEDs on one node, and save yourself from the real estate of two 18 to 20 pin chips.  The IR Toy has already been redesigned with a different FET to handle more current, and you could select yet another FET with even more power.  If you hit the limit, then you can double up - instead of 8 IR LEDs on one FET, you could do 4 on each of two, etc.  Just be sure to give each IR LED its own current-limiting resistor, and it should be fine to share all the current on one transistor.

Re: USB IR Toy update

Reply #19
[quote author="rsdio"]
As an aside, the 74LS374 only handles 24 mA (2.6 mA when hi), so another chip is needed to boost the current.
[/quote]

Yes the Slink-e (schematic) used a TD 62083 8 channel darlington sink driver (datasheet) to provide enough current for the 8 leds.  It draws power off the +9V supply to the box.

Re: USB IR Toy update

Reply #20
Thanks for the part number - it was too small to read in the GIF of the schematic.

My point is that you can replace both chips with a transistor or two, saving a lot of board space and money, not to mention passive current losses.  But you probably do have to pay attention to duty cycle and other things.

Re: USB IR Toy update

Reply #21
[quote author="rsdio"]
My point is that you can replace both chips with a transistor or two, saving a lot of board space and money, not to mention passive current losses.  But you probably do have to pay attention to duty cycle and other things.
[/quote]

I understand your point with regards to using a FET to replace the darlington array.  However I don't see how a transistor or two would let me control 8 IR LED (zones) independently.  In case it's it's not clear I'm looking for the capability to to send IR output to a specific zone, excluding the others.    

FWIW, My current use case for the Slink-e is I have 3 of its IR outputs going to 3 different rooms remotely controlling 3 different air conditioners (mitsubishi mr. slim).   They all use the same IR code set, no addressing as far as I've been able to find).   Note: The slink-e isn't being made any more, and I'll need to replace it at some point.   

One of the attractive things about the USB IR Toy is the price point., so I suppose I could also solve the problem by just buying multiple USB IR Toys, but there wouldn't be much learning involved in that.

I think there is another benefit the slink-e gets from using the 74l374, it has tri-state outputs.  I'm pretty sure (but need to test it) that the LEDs are completely off when not in use (Output enable not set).

Re: USB IR Toy update

Reply #22
[quote author="rct"]I understand your point with regards to using a FET to replace the darlington array.  However I don't see how a transistor or two would let me control 8 IR LED (zones) independently.  In case it's it's not clear I'm looking for the capability to to send IR output to a specific zone, excluding the others.    

FWIW, My current use case for the Slink-e is I have 3 of its IR outputs going to 3 different rooms remotely controlling 3 different air conditioners (mitsubishi mr. slim).   They all use the same IR code set, no addressing as far as I've been able to find).   Note: The slink-e isn't being made any more, and I'll need to replace it at some point.[/quote]That sounds like a cool project.  Yes, your requirements call for something different than just 8 duplicated outputs, which I assumed someone would want for extra power and distance.

In your case, it might be difficult to drive all 3 rooms with different commands at the exact same instant, but you could control one LED at a time.  If you built a circuit where some of the unused PIC pins provide a select address, then a decoder chip and current boost would work.  Depending upon your budget, you could use the 8-channel chips, or just stick to exactly 3 circuits.  Maybe a 2-to-4 decoder with 3 transistors.

Remote-controlling similar devices in different rooms: application for RF header

Reply #23
This is where my proposal of using the I/O header to connect RF modules (cheap from eBay etc.) directly to the USB Toy (using baseband OOK without IR carrier modulation for these) comes into play:

In most jurisdictions, there are some 2 or 3 ISM bands available, each with a number of channels and allowing various modulations - so one would need a fairly huge mansion to run out of different RF transmitters/transceivers to cover each room with its own wireless IR extender (e.g. something like http://www.airwave.com.tw/IR-Extender.html or http://www.marmitek.com/en/catalogus/pr ... roduct=220 - fitted with another RF receiver module if need be) - or on some devices, directly fit a module to feed in the RF receiver output where they'd expect the demodulated IR.

Re: USB IR Toy update

Reply #24
Sorry I didn't update this sooner. Here's the first prototype boards.

Changes from previous version:
1. IR RX to header
2. IR TX to header
3. Flipped ICSP header
4. Frequency counter connected to INT1 for alternate interrupt type

This will probably be incremented to v2 because of the new hardware features. The new 'v' command in firmware v1.05+ will report, for example, v205.

We'd really like to release this hardware as BY-SA, but the USB stack (microchip) and VID/PID sub-license make it a bit hairy. We haven't decided what to do yet.
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Re: USB IR Toy update

Reply #25
[quote author="ian"]We'd really like to release this hardware as BY-SA,[/quote]What is BY-SA?
Quote
but the USB stack (microchip) and VID/PID sub-license make it a bit hairy. We haven't decided what to do yet.
I cannot say what would work for everyone else, but I would be perfectly happy to compile the firmware myself, using the Microchip USB Stack sources that I already have obtained on my own, and Flash the firmware with a PICkit 2 with ICSP.

I realize that I might be in the minority, though, since most people might not want to mess around with MPLAB, etc.  But I thought I would put it out there as an example of what would be acceptable to me, at least.  Is it worth putting up a poll?  Can we even do polls on this forum?

Re: USB IR Toy update

Reply #26
Creative commons Attribution Share-Alike, it was the same with a non-commercial clause because of the agreements we signed for the USB VID/PID and USB stack.

I think you are among the <1% of users who would be able to compile and program the firmware yourself. This forum does polls, there's a new poll button next to the new topic button.
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Re: USB IR Toy update

Reply #27
Maybe you can post a "How to" on the compilation of the Microchip USB stack, or just show any modifications to the sources.

Re: USB IR Toy update

Reply #28
The postman brought these boards (pic), and some others.
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Re: USB IR Toy update

Reply #29
Assembled and tested, front and back pictures attached. I really like the key on the back, super classy.

Don;t have the IR detector yet, will get it in a few days and write supporting firmware.
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