STATUS UPDATE: USB IR Toy v2

On Monday we post status updates on new projects. This will cover project development, and gritty details like last minutes changes and production problems.

USB IR Toy v2 has completed manufacturing and is in testing now. It will probably be available in the next couple of weeks.

The IR Toy has traveled a rocky road. V1 took a lot of tries to get right, but that still wasn’t enough. The first batch of v1 had numerous problems with the transmitter section: backwards LEDs due to a backwards silkscreen, a too-large current limiting resistor that resulted in bad range, and a high-power LED inappropriate for the design.  The second batch, v1a, corrected the LED orientation and resistor value, but the transmitting power remained fairly low.

We tried a bunch of different v2 prototypes before setting on a production-worthy successor to v1:

  1. REV1 added an IR frequency detector and breakout area to the v1 design, but did nothing to address the transmit strength
  2. REV2 added two more LEDs so higher power could be used with a smaller SMD resistor
  3. REV3 finally added a constant current driver for better transmit power. It also jumped to a 3.3volt PIC 18F25J50 design due to price increases for the 18F2550 chip. A lot of work is still needed to get the firmware going on the new chip, so this will be delayed and used as IR Toy v3 in the future
  4. REV4 uses a 18F2550, but we added the constant current driver from REV3 and moved to 0603 parts

REV4 is the final design. The IR range is greatly improved for those who use it, but not at a great additional cost for the majority who don’t use the transmitter.

The QSE159 sensor and rising cost of 18F2550 PIC chips increased our actual cost more than $1. We’ll probably have to pass it on as a price increase. It’s disappointing because $20 shipped worldwide is a great price. We’ll try to get the cost back down eventually by using a cheaper PIC chip in v3.

IR Toy v2 development details are on the wiki.  See the early revisions, current schematic, tests, and design calculations.

Get one of the last IR Toy v1 for $20, including worldwide shipping. V2 will be more expensive.

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