Just thought members might be interested in what I'm playing with at the moment, I'm involved in a project to design and build a data logger project for a friend, so for a start I've been playing with doing both the PIC side and the PC side as well, as it needs to be uploadable to a PC to display a graph of the resulting data.
There's a number of different points to consider, but while playing I thought a simple two channel voltage logger would be handy, so I put one together using an 8 pin PIC 12F1840 and an FTDI USB/Serial converter, which simply receives an instruction from the PC, does two readings (actually 20 and averages them) and sends them back. The PC then plots this as a graph.
I've also recently been playing with a DHT22 temperature/humidity sensor - and this morning I thought "why not log that as well" - so I've made a quick PIC program, based on the existing hardware I've been using (16F1827 based), and simply fed the output to the two channel logger software used with the 12F1840 voltage logger (which is why the labelling doesn't make any sense).
Here's a screen shot of it's first run:
The red trace is humidity (relative %), and the blue is temperature (degrees c) - the first 'blip' is me breathing directly on the sensor, and the second larger 'blip' is me squirting the sensor with a can of freezer. The sensor is taking a VERY long time to recover though, the temperature is back up to 14.8c now, but the humidity is still 99.9%
The PC program by the way is written using Lazarus, a free 'Delphi type' compiler.
There's a number of different points to consider, but while playing I thought a simple two channel voltage logger would be handy, so I put one together using an 8 pin PIC 12F1840 and an FTDI USB/Serial converter, which simply receives an instruction from the PC, does two readings (actually 20 and averages them) and sends them back. The PC then plots this as a graph.
I've also recently been playing with a DHT22 temperature/humidity sensor - and this morning I thought "why not log that as well" - so I've made a quick PIC program, based on the existing hardware I've been using (16F1827 based), and simply fed the output to the two channel logger software used with the 12F1840 voltage logger (which is why the labelling doesn't make any sense).
Here's a screen shot of it's first run:
The red trace is humidity (relative %), and the blue is temperature (degrees c) - the first 'blip' is me breathing directly on the sensor, and the second larger 'blip' is me squirting the sensor with a can of freezer. The sensor is taking a VERY long time to recover though, the temperature is back up to 14.8c now, but the humidity is still 99.9%
The PC program by the way is written using Lazarus, a free 'Delphi type' compiler.