Updates and Design Files
I hope you all had a great holiday season. It was great to be able to have everything sent out before so we could enjoy some time off.
We are now back at it again and working on documentation and are also hopping to have the ability to buy additional minions set up here in the next week or so.
A google group has been started over at https://groups.google.com/d/forum/minioncity by Baruch. I’ll be watching there as questions come up as well as comments to the blog.
So first off here is the schematic of the minions.
There are a few key differences from the normal arduino.
First off is the lack of an led on pin 13. Routing was getting a little tight so removed it. The two LEDS on the board are tied to TX and RX. Which is why you see them blink when downloading your code.
The second is the radio. It uses 5 lines to talk to the processor.
- MOSI
- MISO
- SCK
- D3
- D10
MOSI,MISO and SCK are part of the spi bus and are not part of the numbered ports in arduino. As a side note if you want to reprogram the processors bootloader you need a pullup resister on D10. D10 is the select line on the radio. The RF12 library uses an internal pullup resister to do the job but when you are resetting the processor to burn in a bootloader it is released and causes problems with the programmer. The battery shield added a 10k resister for programming.
D3 and D10 are part of the normal pins and shouldn’t be used when you are using the radio.
The eagle files for the main board and the battery shield are available at
http://www.minioncity.com/download/
(Schematics and board layout)
Great! Thanks.
I’m now feeling bad that I said to friends that the minion is great but seriously lacks documentation. This fills the gap nicely.
I’m wondering also what is then the relation between pin 16 and the amber led. It looked like the output on pin 16 lighted it up.
Pin 16 on the processor or the header breakout?
(16 on the processor is tied to the crystal and shouldn’t affect the LED)
pin 16 as referred from Arduino when I tried to probe all pins as leds. Well, I actually was wrong and it is pin 17. A simple blink sketch on pin 17 turns the led on and off with no serial traffic.
The extra pins have been mapped to the ICSP header. Their mappings are:
D14 – MISO – PB3
D15 – SCK – PB1
D16 – MOSI – PB2
D17 – SS – PB0
D17 or SS is also the RXLED see
http://arduino.cc/en/Hacking/PinMapping32u4
for more.
I’m a novice in this microcontroller world and I am completely baffled as to the different numbering and naming schemes. How do I find what Arduino pin number is assigned to on the Atmel chip and on the board?
The arduino world takes care of that for you. You just need to go by the labled number on the board. That will match up with the ones in the arduino enviroment.
D0-D13 are the normal digital inputs.
D14-D17 are special inputs that have more than one function. Such as the D17 it is used as both the RXLED and also the SlaveSelect on the spi bus. Since we are using the SPI bus with the radio you don’t want to touch D13-D16
D17 is fine to use because the RF12 library uses D10 instead of D17 as the select line.
Looking forward to be able to order a couple of these! Great work!
I would buy these if they were available somewhere for purchase.
Will these be available somewhere in the future?
Thanks,
Ray….
I missed out on Kickstarter… when can I order a few? Could you email me when you have more? Thanks!
We just started opening up to new orders, see our shop page (http://www.minioncity.com/shop/)
Nate
Are you accepting any more orders for minions? I got a couple through the kickstarter, but some more could be useful.