STICKY: You HAVE installed the jumper on J7 haven't you?

[alexeames]

Quite a few reported "issues" people have had with Gertboard Rev 2 ended up being due to the fact that they had not installed the jumper on J7 (like it tells you to do on page 9 of the manual)...

To send the 3.3V power supply to the components on the Gertboard, you need to install a jumper over the top two pins of the header J7. It is near the lower right corner of the board; see the photo and diagram in Figure 7.

And while we're here, make sure you haven't put the Gertboard on backwards. This is what it should look like...


And YES, the leds are meant to be lit when the Gertboard (V2) is powered up.

[silverfox0786]

i think the confusion is a little deeper than that

yes it says that on page 9 but then as you go along the manual

you will find the test programs when showing which jumpers to install to do certain tests does not mention or show in the figures that the J7 jumper needs to be attached

so people get confused as to whether it actually needs attachment or not

[alexeames]

There is no confusion. It should ALWAYS be on if the Pi is attached
(unless you have a non-standard setup and really know what you're doing).

[silverfox0786]

To send the 3.3V power supply to the components on the Gertboard, you need to install a jumper over the top two pins of the header J7. It is near the lower right corner of the board; see the photo and diagram in Figure 7.

Thats my point when i first started using the gertboard i was unaware of this as the statement above is ambiguous

it says to send 3.3v to components rather than it always needs to be connected at all times when using the board components

The statement suggest to the end user who has no knowledge that its optional

i would rephrase that

3.3V is not enabled by default on the Gertboard. This is a Mandatory Requirement to send power to the components, you need to install a jumper over the top two pins of the header J7. It is near the lower right corner of the board; see the photo and diagram in Figure 7
When bypassing the Gertboard and only using the pins of J2 Header GPIO from RasPi the jumper can be removed.and bottom Pin on J7 will give you 3.3V (Pin1-RasPi) with ground (Pin6-RasPi) connection from any GND point

[alexeames]

it says to send 3.3v to components rather than it always needs to be connected at all times when using the board components

Which is why I started this thread to give a totally unambigous conclusion that...

"The jumper on J7 should be installed on the top two pins at all times when your Gertboard is connected to your Pi"

It really is that simple and there should be no need for doubt. I expect that part of the manual will get some attention for the next revision. In the meantime, we have this sticky.

[silverfox0786]

Your right this thread is a good idea as even i was unaware of the jumpers function before

infact i think it was you that said even to me it is a MUST when i asked for support

[pstorey]

Just thought i'd wave the forgot to add the J7 jumper flag.

Great advice with simply stating it always needs to be installed..

[wally]

Hi,
thanks for making the J7 default setting clear.
What is a possible scenario J7 not to be set
or shorten 2-3 instead of 1-2 ?
Which Version/ Revision is the board "21.Oct.2012" ?
Always talking about Version/Revision but its not
printed on the board.
What is the "5V" jumper J24 for ?
Anything else to be set (jumper) before first run ?

thx wally

[Gert van Loo]

Those are good questions.

Hi,
thanks for making the J7 default setting clear.
What is a possible scenario J7 not to be set
or shorten 2-3 instead of 1-2 ?
...
thx wally

If you know that the gertboard will draw no more then 25mA.
That would be the case if you have max one or two LED's on, nothing running on the micro controller
and do not draw any significant current from the buffers set to 'output mode'

Which Version/ Revision is the board "21.Oct.2012" ?
Always talking about Version/Revision but its not
printed on the board.

There are only two revision: the kit and the ready made.
Most people know if they have soldered it themselves or not

What is the "5V" jumper J24 for ?

If you assemble the switch mode supply.
Look here for more info on that:
http://www.raspberrypi.org/phpBB3/viewt ... 88#p324121

Anything else to be set (jumper) before first run ?

No

[wally]

Gert,
If one knows this

There are only two revision: the kit and the ready made.
...
Most people know if they have soldered it themselves or not

it's quite clear even if one not belongs to the majority of paople

If you know that the gertboard will draw no more then 25mA.
That would be the case if you have max one or two LED's on, nothing running on the micro controller
and do not draw any significant current from the buffers set to 'output mode'

This is a scenario for (not short any of the J7 pins XOR shorten J7:2-3) ?

If you assemble the switch mode supply.

Never heard about or seen "The switch mode supply"
i read http://www.raspberrypi.org/phpBB3/viewt ... 88#p324121
by timb » Thu Apr 04, 2013 10:01 pm
by Gert van Loo » Fri Apr 05, 2013 12:14 am
and do not get behind, which power supply you are talking about.

Do you mean to solder a e.g. 7805SR-C and necessary peripherals
on the area with the not used free footprints and to connect external power to it ?
btw. this device is really expensive: farnell 23€

Seems i need to study the manuals more intensively
thank you for reply
wally

[Gert van Loo]

Seems i need to study the manuals more intensively

The switched mode supply is not in any manual.
It only appears in the schematic as "do not fit".
If your are an electronics expert and willing to take up a soldering iron you can install the parts.
I have tested it and it works.

[wally]

Gert,

first i need to rethinking on powermanagement for USB Hub, Raspi and connected Gertboard.
What PSU current should me free of all sorrows ?
1A is not sufficinet i fear for all

[Gert van Loo]

What PSU current should me free of all sorrows ?

The AP1509 can go up to 2A. I think that should solve most of your needs.

With hindsight I should have selected a different part. This one is 150KHz and thus needs
a rather chunky inductor. A 1MHz switcher would have been better.

[jkeating]

When I install the 3v3 jumper all of the LEDs on my board stay lit up all the time. Is that how its supposed to be?

[Gert van Loo]

When I install the 3v3 jumper all of the LEDs on my board stay lit up all the time. Is that how its supposed to be?

yes

[baantonia]

I was completely unaware of this and have been using the board without issue, the LEDs have been lit when I wanted them lit and the SPI ADC chip returned data. Going back to the documentation, the bottom of page 9 and the top of page 10 clearly shows this link made on J7, must have skipped this bit, whoops!

[Wizzabeck]

I'm getting a little confused. Having recently bought a gertboard and wallowed in the manual I missed the buttons test and went straight to leds. Like others I assumed the J7 jumper wasn't necessary and when I started the leds test, those wired up flashed on and off when the program was run and the rest switched on until the end. The board is attached to a PiZero. It was only when I decided to try the button test that the leds didn't co-operate. So why is it necessary to "always have the J7 jumper on" when it clearly is not necessary for at least the leds test (and in fact other things I have been doing with them). How are the leds powered?
TIA
Ken