DEV-00030 Opto Rating, and other questions

Development Boards MicroMod
1

Just purchased the DEV-00030. Nice product!

  1. What are the maximum input voltages for the opto-isolators?

  2. Is there an instruction manual for the board? (I have the schematic and the two-page PDF, but was looking for more of a users manual).

  3. Why does it have a resonator AND a crystal?

Thanks!

MML

2

mikemolang:
Just purchased the DEV-00030. Nice product!

  1. What are the maximum input voltages for the opto-isolators?

  2. Is there an instruction manual for the board? (I have the schematic and the two-page PDF, but was looking for more of a users manual).

  3. Why does it have a resonator AND a crystal?

Thanks!

MML

I haven’t used that board but…

  1. Schematic says they are 4N37 optoisolators. So look up that part and factor in the 330 ohm resistor and LED shown on the schematic, so that you choose a max voltage that does not exceed the max current specs of the external or internal LEDs. A guess would be: stay below 10mA.

  2. Olimex rarely creates a user manual. Try asking them after rummaging around their web site. On SparkFun’s product page, this link exists

http://www.sparkfun.com/datasheets/AVR/avr-io-b.pdf

  1. I see only a crystal in the schematic. Sometimes AVRs have a crystal or resonator for the main clock and a 32768Hz watch crystal for the real time clock - optional.