Need a little help - I just bought a v3.1 Stalker from Mouser, I have had two of the V3.0 Stalkers for sometime. There's no output to the VCC and 3.3V pins on the power header, and no 3.3V output to the XBee socket.
Amazingly, the board works for loading sketches, just no output to the power header or XBee!
I ordered a replacement, and it's the same with the replacement. I did about a hundred cross-checks with my old Stalker and other Arduino boards. On all of those, I see the correct voltages on the power header.
I did some probing on the board and it appears that both v3.1 boards are lacking a transistor in the power supply (the one next to the I2C Grove socket) and a resistor next to the XBee socket. I traced the pads of the missing resistor, one pad is at 3.3V, the other is connected to the XBee VCC pin. So, sure seems like that's the cause. As for the transistor, it's more complicated to trace, as Seeed no longer has component id's printed on the board..
If you have a Stalker v3.1, can you take a look at it and see if these components are present? I'm currently waiting for Seeed to get back to me. I'll try to post a picture later.
Thanks!
Cropped pic from Seeed of the board layout, missing components are shown in green. Can't post pics of my board, photos are too big for the forum.
Have you already tried:
pinMode(9, OUTPUT);
digitalWrite(9, HIGH);
Arduarn, other than bring pin 9 high, what would that code snippet do? I can drive the digital pins high, but on the power header there's no output on the VCC or 3.3V pins, and no connection to VCC at all for the XBee.
pbanders:
Arduarn, other than bring pin 9 high, what would that code snippet do? I can drive the digital pins high, but on the power header there's no output on the VCC or 3.3V pins, and no connection to VCC at all for the XBee.
It is supposed to be connected on the board to two MOSFETS that control power. Did you try it?
OK, you're a genius. Where is this documented, I completely missed it. After bringing digital pin 9 high, I now have VCC and 3.3V on the header, and the XBee supply pin is at 3.3V. I assume this is a power-saving mode that's enabled by default?
Any other gems about the v3.1 like this you care to share? They also claim the power supply to the I2C port is switchable from 3.3 to 5V, how is that done? Thanks again....
Well the hint for me was that you had the old board which worked and the new one that didn't.
Looking at the Seeedstudio page for the 3.1 it said:
Seeeduino Stalker V3.1 is not just a simple update of V3.0.The main surprise you'll find about the board is impressively low power consumption, in sleep mode,
That's a big hint at what's changed. And further:
Please turn on the power before using Bee, grove port, 3.3v and 5v port
Ding.
I didn't initially see anything by skimming the Wiki documentation, but a look at the schematic showed the MOSFETs and control pin. Another look at the Wiki revealed, admittedly rather poorly stated, what was necessary:
D9 is controlling the power of Vcc of Bee socket, if you need power to a Bee, you should make D9 HIGH: digitalWrite(9, HIGH), and don't forget to pinMode(9, OUTPUT) in the Setup.
It would have been simpler if they had simply stated what the VB_CTRL meant in their pin map.
pbanders:
Any other gems about the v3.1 like this you care to share? They also claim the power supply to the I2C port is switchable from 3.3 to 5V, how is that done? Thanks again....
Sorry, never touched the board; just figured there would be an easy solution, which in this case was simply reading the provided documentation.
Have fun with it anyway.
Yeah, I just went and found those references, too. Just figured it would work like any of the older Stalker boards or like the other Arduino boards. Easy fix, as you say. Again, thanks for finding that and letting me know about it.
