Arlington TX - (817) 265-6435



HELP WANTED for Micro Controller design with RF interface

We are looking for someone to take over a project to design a data logger 
having the features listed below.  I envision it being done with a stamp 
micro-controller and an RF interface but you can offer alternatives.  A 
prototype is to be built and tested using standard available parts but not 
a PC.  A custom circuit board can be used.  No packaging or enclosure is 
required.  No custom IC chips to be used but CPLDs can be used.  The final 
design information should be sufficient for me to create another copy of 
the device.  Material costs should be quoted separately.  Priority from 
most important to least important in evaluating the bids would be:

- Material costs of the device
- Low power consumption
- Memory Size
- Simple, Compact hardware design (this device is not a PC)

The data logger must have the following hardware features

a) Input for ASCII serial data.
b) 2 digital on/off inputs.
c) Memory to log and store a minimum of  30 Kbytes of logged data.
d) Memory space to store a minimum of  400 bytes of changing variables.
e) Replaceable/rechargeable battery for backing up the memory and running 
   the circuit
f) External DC power input for charging the battery and running the 
   circuit at the same time.
g) RF interface for uploading stored data
h) Input to reprogram the algorithms.

The data logger will receive a certain amount of ASCII serial data from an 
external device at predetermined intervals.  Between each interval, this 
ASCII data, variables, and the state of both digital inputs would be 
passed to an algorithm.  This algorithm would be written by someone else 
and could be up to 32 Kbytes in size.  Depending on the results of the 
algorithm, a new ASCII string will be passed back to the system to be 
appended to memory and change some of the variables. The system must also 
tell the algorithm when a computer with an RF interface is in range.  
If so, then the algorithm may issue a command to the system to upload the 
data to the computer.  Once the computer verifies the data is valid, it 
should send a command to the system to reset the memory or else retry 
sending the data.  The algorithm will change from time to time so the 
system should accept an industry standard language and be reprogramable.  
You can setup the system using a program for which the algorithm is a 
subroutine of that program.

Quote the following as an option

a) Input for a standard "off the shelf" alphanumeric keyboard (your choice 
   of type) for additional ASCII input to be sent to a variable.

b) Output for 1 line text display, minimum of 20 characters for assistance 
   in seeing what is being input by the keyboard.  Data would not be 
   passed to the variable until the data in the display is edited 
   correctly and accepted with the enter key.


Call Tony at 817-265-9024.
Located in Arlington TX.