Arduino Multi-Channel RTD Shield with RS232 and RS485

Our first shield design rolled out last week. You can find the Arduino Multi-Channel RTD Shield with RS232 and RS485 in our store.  We also strive to have the best documentation possible.  The docs for the RTD + RS232 + RS485 shield are available here.

We left it running for days to make sure everything was stable.  Everything seems to be running great.  We set it up to read the resistance values of precision resistors that were connected in a four-wire configuration.  It took about 40 milliseconds to cycle through all of the channels and get a new reading back to the Arduino.  On the shield it takes multiple readings and calculates the median value, which it saves and reports to the Arduino when queried.  This provides some basic filtering and eliminates any outliers that may have been encountered.

The shield is easy to use and has some nice features.  We tried to come up with examples that showed how all of the routines work.  If you have any questions, let us know!

Lessons Learned

  • Don’t try to access the EEPROM while in the I2C slave interrupt.  You can’t read the data from the EEPROM fast enough to properly service the I2C slave response to the master even with clock stretching enabled.