grantsmith
Joined: 06/07/2014 16:15:35
Messages: 4
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Hi,
Looking at http://www.anarduino.com/miniwireless/#schematic I deduce that the following pins are used by the internal electronics, assuming RTC, Radio and Memory are all being used by a sketch:
RTC: D3, A4, A5
Memory: D5, D11, D12, D13
Radio: D2, D10, D11, D12, D13
Questions:
1. Why is there a pull-up on D3 ? Can I use D3 and Interrupt 1 ?
2. If I don't use RTC, Memory or Radio (or any combination) in my sketch, does that mean the pins used above for those two are accessible ? Or will there be unpredictable side-effects ?
3. The schematic is for RFM12B - Has anything changed for the LoRa Miniwireless modules ?
4. If I power from 3.3V into VCC (NOT VIN), does this completely bypass the voltage regulator ? I want to create a low power/sleeping battery powered situation where the module is woken up by an interrupt on pin D3, without the inefficiencies of a voltage regulator in the way.
Thanks,
-Grant.
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Rick
Joined: 30/05/2014 22:08:56
Messages: 93
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grantsmith wrote:Hi,
Looking at http://www.anarduino.com/miniwireless/#schematic I deduce that the following pins are used by the internal electronics, assuming RTC, Radio and Memory are all being used by a sketch:
RTC: D3, A4, A5
Memory: D5, D11, D12, D13
Radio: D2, D10, D11, D12, D13
Questions:
1. Why is there a pull-up on D3 ? Can I use D3 and Interrupt 1 ?
2. If I don't use RTC, Memory or Radio (or any combination) in my sketch, does that mean the pins used above for those two are accessible ? Or will there be unpredictable side-effects ?
3. The schematic is for RFM12B - Has anything changed for the LoRa Miniwireless modules ?
4. If I power from 3.3V into VCC (NOT VIN), does this completely bypass the voltage regulator ? I want to create a low power/sleeping battery powered situation where the module is woken up by an interrupt on pin D3, without the inefficiencies of a voltage regulator in the way.
Thanks,
-Grant.
Hi Grant, here's my .02
Yes those are the pins in use.
1 - The schematic shown is the for the MW-12 with RFM12B in which interrupt enable is active LOW, so I added a pullup to differentiate between states even when the radio int pin is high impedance.
The pullup could be removed for other radio types, like rfm69 for example, whose state is opposite that of the 12b. Thanks, good point.
2 - If you don't want the RTC or MEM, then you can order the MW without these for a lot less. Otherwise, here are my comments: if the radio is put in a sleep state, then you should be able to use D2 and D10 without issues. As for the memory, you might have problems using D5 for other things during SPI bus operation.
3 - Yes, the FTDI 6-pin connect Power comes into VIN (and not VCC). In fact all MW have this as VIN input instead of VCC--with the exception of the first MW, which is the 12B version. When the current stock runs out, I'll do another pass on it, making it VIN as well.
4 - Yes, it bypasses it if you put 3.3V directly into VCC, and this is the way I previously used it as well. However--> As for low power, I would suggest going with our new MW Low Power Series. It features extremely low quiescent of < 50nA, which is pretty much best on the market. I'm in production now, so they should be available soon... Here's a teaser: http://forum.anarduino.com/posts/list/15.page
Thanks for your post...
Cheers,
-Rick
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