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Lake · 03-30-2008, 02:22 PM

I made another post related to the electronics of the car in my main build thread. Duplicated below:

------
Here is the Data Acquisition Device (DAQ) I referred to earlier.

You can see I have a few random lights dials and switches on the easy access pins on the left. Those are just for testing the feedback loop through my software. There are break-out boards connected on the right which include many more pins than the left and also duplicate pins on the left. Once finally installed I'll just have two D-sub cables as the end of the wiring harness, but for now the screw terminals are really handy.

The LJ is quite the device. The full specs are on their website ( http://www.labjack.com/labjack_ue9.php?prodId=26 ). The main selling point for me is the Ethernet connection so I don't have to worry about drivers. Every platform does TCP/IP, and I can write my own code against that.

Here's another photo that gives you a broader picture of how things are to be connected:

Edit: The ethernet cables run off to my desktop switch for now. That way I can talk to the devices from the laptop to test code more quickly than installing it on the gumstix.

The little male to male USB adapter will end up being a hub for multiple devices. In this case it's only plugged into a USB/Serial adapter (I bought several of these little FTDI ones from Parallax) which in turn is plugged into one of the AEM Thermocouple Amplifiers. There are two TCs plugged into that.

The AEM TC Amps are pretty neat in that they provide both a serial data stream and a 0-5V analog signal for each of the 4 Thermocouples (that explains the wires going from the AEM TC Amp to the LabJack, another test channel) and for cheaper per channel than most TC Amps of any sort from MoTeC or even those meant industrial, or the lab, or whatever.

Alternatively:

I'm considering using a MoTeC E888 in place of the AEM TC Amps. The E888 feeds its data to the M600 via CANbus. The cause for reconsideration is that with the latest version of the M600's software I can send arbitrary telemetry data via the Serial telemetry stream. So the E888 sends its data to the M600, and the M600 rebroadcasts it (alongside other data) to the gumstix. This way the M600 knows all 6 (or 7) EGTs. The alternative was to wire the 7th channel via one of the analog outputs into the M600 so it would have an EGT feed. With the E888 I don't use an analog input on the M600, and I get several additional analog inputs + digital IO that can interact directly with the M600 or just be passed along to the gumstix.

03-30-2008, 02:22 PM	#4
Lake Newbie Join Date: Jan 2005 Posts: 53 My Photos: ()	I made another post related to the electronics of the car in my main build thread. Duplicated below: ------ Here is the Data Acquisition Device (DAQ) I referred to earlier. You can see I have a few random lights dials and switches on the easy access pins on the left. Those are just for testing the feedback loop through my software. There are break-out boards connected on the right which include many more pins than the left and also duplicate pins on the left. Once finally installed I'll just have two D-sub cables as the end of the wiring harness, but for now the screw terminals are really handy. The LJ is quite the device. The full specs are on their website ( http://www.labjack.com/labjack_ue9.php?prodId=26 ). The main selling point for me is the Ethernet connection so I don't have to worry about drivers. Every platform does TCP/IP, and I can write my own code against that. Here's another photo that gives you a broader picture of how things are to be connected: Edit: The ethernet cables run off to my desktop switch for now. That way I can talk to the devices from the laptop to test code more quickly than installing it on the gumstix. The little male to male USB adapter will end up being a hub for multiple devices. In this case it's only plugged into a USB/Serial adapter (I bought several of these little FTDI ones from Parallax) which in turn is plugged into one of the AEM Thermocouple Amplifiers. There are two TCs plugged into that. The AEM TC Amps are pretty neat in that they provide both a serial data stream and a 0-5V analog signal for each of the 4 Thermocouples (that explains the wires going from the AEM TC Amp to the LabJack, another test channel) and for cheaper per channel than most TC Amps of any sort from MoTeC or even those meant industrial, or the lab, or whatever. Alternatively: I'm considering using a MoTeC E888 in place of the AEM TC Amps. The E888 feeds its data to the M600 via CANbus. The cause for reconsideration is that with the latest version of the M600's software I can send arbitrary telemetry data via the Serial telemetry stream. So the E888 sends its data to the M600, and the M600 rebroadcasts it (alongside other data) to the gumstix. This way the M600 knows all 6 (or 7) EGTs. The alternative was to wire the 7th channel via one of the analog outputs into the M600 so it would have an EGT feed. With the E888 I don't use an analog input on the M600, and I get several additional analog inputs + digital IO that can interact directly with the M600 or just be passed along to the gumstix.