HOW-TO Add an Addtional IR Reciever to FIRST IR Board

[The Lucas]

A week or so ago I added an additional IR reciever in parallel on my FIRST IR Board. It works well, allowing IR sensors facing forward and backward to accept signals (good coverage area on the robot). The actual soldering required to install the external IR sensor was simpler than I expected (Reuben did a great job). Locating the correct places to attach the wires was a little difficult, but the pictures should help. I wanted to post these instructions earlier, but I haven't gotten around to it till now (right before ship). Hopefully, you still have time to attach the sensor before your first competition. Here it goes:

DISCLAIMER: Modify your IR Board at your own risk. Please don't blame me or Bob Grieb if your board is damaged during the mod. All mods have some degree of risk (that is also why they are so fun )

First here is the required/recommened hardware (thanks Tauntek for the list):
Vishay TSOP34838 IR Receiver Module
100 ohm 1/4 W resistor
4.7 uF 50V electrolytic capacitor
3 short (~8") thin (24-28 AWG) wires
Tauntek PC-RS2 blank PC board (optional, but a nice cheap PCB)
I bought all these components from Tauntek as part of my TinyIR2 order (I am using TinyIR2 as backup and it also has 2 IR sensors)
For simplicity, Tauntek can provide all these parts to you in one order, just tell Bob Grieb what you want to do (he is very helpful through email).

If you bought the PC-RS2 board from Tauntek, populate it according to the parts placement guide. If you dont have the board, just make sure to install the 4.7 uF cap across pins 2 & 3 of the IR Sensor (postive side of cap on pin 3). Here is a pic of my completed PC-RS2.

The 100ohm resistor must be put in series with pin 3 of the IR sensor. On the PC-RS2 board, solder one side of the resistor in the +V through hole. Solder a wire to the other side of the resistor. Solder the other 2 wires to their though holes on the board (or the pins on the IR sensor).

Now it is time to attach the wires to the FIRST IR board. BE VERY careful, the board is sensitive to both heat and ESD. I recommend looking at the pictures and marking the solder through holes with a Sharpie (you can see my marks) before taking the iron to the board. This picture has notes to indicate where each wire goes. I recommend soldering the tip of each wire ("tinning") first. Then melt the solder in the corresponding hole on the board and quickly insert the wire. That is how I recommend soldering it but there certainly are other methods/tools. OK, now that that everything is soldered I recommend checking for shorts before powering up (it would be very bad to do all this work only to fry the board on startup).

Now you have twice the IR coverage area and the new sensor can be direct any angle you want. Also, Realize that now you have twice the IR interference. Thanks to Bob Grieb for all his help understanding the board.

P.S. Has anyone already modded their board? Bob said multiple teams inquired about it.

[dtengineering]

Originally Posted by The Lucas

P.S. Has anyone already modded their board? Bob said multiple teams inquired about it.

We just de-soldered the IR receiver, then re-soldered it to a length of servo cable. Now we have the board able to mount on the robot's electronics board, but the receiver able to go anywhere.

We considered replacing the receiver with a non-38kHz one to reduce interference, but it seemed to make more sense to leave it "standard" so we could co-ordinate our robocoach signals with our alliance partners and get control from both ends of the field.

It may also be possible that a PNA4602M IR receiver could be used if the Vishays were difficult to find. Looking at their datasheets they appear to have many similar characteristics.

Jason

[Uberbots]

Originally Posted by dtengineering

We just de-soldered the IR receiver, then re-soldered it to a length of servo cable. Now we have the board able to mount on the robot's electronics board, but the receiver able to go anywhere.

We considered replacing the receiver with a non-38kHz one to reduce interference, but it seemed to make more sense to leave it "standard" so we could co-ordinate our robocoach signals with our alliance partners and get control from both ends of the field.

It may also be possible that a PNA4602M IR receiver could be used if the Vishays were difficult to find. Looking at their datasheets they appear to have many similar characteristics.

Jason

Yeah thats exactly what we did... now we have an array of 8 receivers (my dad went a little overboard...), and a remote with about 4 emitters... so i think we are set (=