pcmhacking.net

If you don't want to wait, they're auctioning off a couple of prototype boards at the moment, but they're a little more expensive
http://www.ebay.co.uk/sch/raspberry_pi/ ... ksid=p3686

Yeah been following the development of it, looks good so far. Last I read there were some issues with part of the toolchain for the graphics side of it but otherwise should be a very handy little board.

I hooked it up to a running engine for the first time, I think I need to switch the LCD to 8 bit mode and look for other ways to speed up the screen refresh - it's a little slower than I'd like.
But at least it works
http://www.youtube.com/watch?v=x9GyRrYKxSk

Nice work I run my logger in 4 bit mode but with an AVR doing just the logger its prob faster than the router running an entire OS.

Some high resolution on the MAP

The router runs at 250MHz and I've stripped out a lot of the 'normal' processes to keep it fast - and my LCD is connected via a USB serial uart @ 38400bps.
The picaxe on the other end of the serial line does background serial rx into a 1kb buffer. The 'foreground' routine just loops checking for a serial rx interrupt, and sends each byte from the buffer to the LCD - starting from the last buffer pos up to the current buffer ptr.
The lcd bytes sent from the router to the screen are a mix of data and cmds for positioning etc - the picaxe currently doesn't do anything more than serial->4 bit parallel conversion.

I'm logging at around 5Hz and part of each cycle includes updating the LCD - and at 38400 I should be able to transfer enough data to update the screen at 40Hz so might have to test the screen on a pc to see whether it's the picaxe/screen or the router that's too slow.
One of those r-pi boards would run 3x faster and I could have the LCD on the GPIOs and do away with the picaxe all together, so might not persist with this until I can get one.

And, my MAP sensor is a high precision model
I've given I think 6 digits to each of the ADX objects that get diaplayed - the logger has no idea that MAP is going to the top right position, so doesn't do any rounding. Maybe I should apply the ADX's "Output Digits" value to the displayed values

I've been re-visiting a few of my unfinished projects recently, so decided to fire up the Raspberry Pi that I got a while ago to see if it was any use as a logger.
It took me a few hours to write a Perl module to drive an LCD from the GPIO pins (I'm amazed no-one had written one yet) and then about 10 minutes to port my logger code to the R-Pi.
End result is 8Hz logging, and a better screen refresh rate so it looks pretty promising
There's enough spare GPIO lines to add a few buttons - and spare SPI, i2c and uart ports which I'll use to add a RTC, 3 axis accellerometer and some ADC inputs at some stage later on.

The only parts required for this version of the logger are:
Raspberry Pi board ($38)
20x4 LCD ($7)
2Gb or larger SD card ($5)
Jumper wires to connect screen to R-Pi board ($3)
Optional - USB thumb drive for storing logs (otherwise it stores them on the SD card, but a USB drive is more convenient)
USB car charger or other 5v supply capable of supplying at least 1 amp
and some sort of case would probably help too

It's not in the same league as VL400's logger, but it's a bit of fun and does what I need.
http://youtu.be/iYu8XQRJmYE - the screen flicker is because I was writing some debug messages to the screen between each update and forgot to turn it back off

I was mucking around with my logger a while ago and wanted some analogue inputs for a 3 axis accelerometer.
I would have used SPI, but the one I had on hand was an ADXL335 analogue sensor so thought I'd use that.
Plus, I have a few more sensors I'd like to add to my car so extra inputs are always handy so I knocked together a USB 10 channel 10 bit ADC module.
I haven't got it properly integrated with the display yet but it's logging data well enough.
Here's a log of me giving it a bit of a shake - the red line is the Z axis, hence the 1g at rest compared to 0g for the X and Y axis: I still need to calibrate the channels - the Y/blue axis is out by about 0.2g...

Nice, very handy addition for dialing in a track car and being able to correlate the engine logs with what was happening to the car.

Now with integrated HD video recording, and I've started experimenting with telemetry overlays this afternoon...
[youtube]http://www.youtube.com/watch?v=iSj_P_VEoDk[/youtube]

YOUR FAR TOO CLEVER!!!

Nice work!