PDA could mean Portable Data Acquisition if National Instruments has a say. Their NI CF-6004 data acquisition (DAQ) module transforms the better-known PDA into a handheld instrument and takes advantage of the unit's built-in processing and wireless communication capability.
The DAQ is a 14-bit resolution, multifunction CompactFlash size card that plugs directly into a PDA's CompactFlash slot. The unit allows up to 200k samples/sec single-channel or 132k samples/sec aggregate sampling on four single-ended analog input channels. It includes NI-DAQmx Base driver software for programming analog input, digital inputs/outputs (I/O), and counters. Each of the four digital I/O channels can be individually programmed as either an output or an input for measuring LVTTL or LVCMOS signals. The output driver is a push-pull configuration.
LabVIEW users can easily transition to the portable format with the LabVIEW PDA software module by downloading a LabVIEW application developed on a PC to the PDA. For users without LabVIEW experience, example programs for PDA execution can be downloaded from NI's website. These programs demonstrate the kind of applications that can be developed. The number of programs that can be stored on the PDA depends on the PDA's memory capability. A program could range from 2 Kbytes to several hundred Kbytes, with the typical program around 200 Kbytes.
Stamp-Size Data Acquisition: Using the CompactFlash Slot in a PDA, National Instruments NI CF-6004 data acquisition module takes virtual instrumentation to portable applications, such as a handheld digital multimeter, function generator, or data logger that wirelessly communicates data to a PC.
Signal connectivity options include the choice of two cables, one with just bare wires for the four analog inputs and four digital inputs/outputs. The other cable has a D-Sub connector that connects to two types of connector blocks. One, a DIN mountable terminal block, allows users to connect their PDA to a fixed location. The other connector block is a shielded terminal block for more portable measurements. The unit targets signal measurements in the ±5V range. Powered by +3.3V from a PDA host, the NI CF-6004 draws 2 mA maximum at idle, 50 mA typical under continuous acquisition, and 68 mA maximum when all outputs are loaded. Potential applications include biomedical and wearable computing, field monitoring and diagnostics, and portable data logging and analysis. One of the more current applications is mobile prototype testing to verify a system's capability in the field.