Bits & Bobs...

Hi everyone, first post on the forum...

Have just (mostly) completed a build of of a RFM12Pi, EmonTX and a low power temperature node. All the software is installed and I have happily tested temperature collection from all extremes of the house. Two questions:

I have used my Gertboard to upload sketches to the two ATMega328's. While they seem to work I am aware of a difference between the Gertboard and the EmonTX and wonderd if this could cause me problems down the line. Namely that the EmonTX runs at 16MHz whereas the Gertboard runs at 12MHz. Voltages are the same at 3.3V, but is there anything else in the basic setup of a ATMega328 I should be aware of?

On a seperate note, I ordered the wrong 3.5mm stereo sockets and don't really want to spend £5 p&p for £1.50 worth of components. Is it possible to buy some from the shop when I place my next order ?

 

Thanks

 

Robert Wall's picture

Re: Bits & Bobs...

Hi Bob, welcome.

I thought I'd answered your post a day or two ago, but apparently not!

On the sockets question, you need to negotiate with the shop just before you put your order in. I don't know how the kits are put together, so there may not be spares available. But it's well worth asking.

Bob Smith's picture

Re: Bits & Bobs...

Hi Robert,

With the sockets sorted, thanks to Glyn, I decided to order a USB to UART programmer from the shop so I could upload sketches from my PC.

All the necessary software and drivers installed ok under Windows 8, Arduino Uno and correct port selected, blue light on the programmer, but every time I try to upload even the simplest sketch I get the generic “avrdude: stk500_getsync(): not in sync: resp=0x00” message. This is the same for both the EmonTX and a low power temperature nodes and every ATMega I have tried.

I have searched the forums and the general response to others receiving this message seems to be a failed programmer. Is there any way to check this or could this be caused by previously using the Gertboard to upload sketches?

Any suggestions gratefully received…
 

Paul Reed's picture

Re: Bits & Bobs...

Have you selected the correct bootloader in the Arduino software, to match the bootloader installed in the Atmega?

i.e. >Tools>Board>Uno (if using a Uno optiboot loader)

Just a thought

 

Paul

Bob Smith's picture

Re: Bits & Bobs...

Hi Paul,

Yes, Arduino Uno selected but the bootloader question in general worries me. As all my ATMega's have been programmed previously using the Gertboard I have never had to put a bootloader on them.

I have tried using the programmer to put a bootloader on, but this also fails to upload. Almost convinced myself its the programmer.

Paul Reed's picture

Re: Bits & Bobs...

If you have a spare Arduino board, you can re flash the bootloaders as per this guide.

I've used it a few times now, and it worked for me.

Paul

Bob Smith's picture

Re: Bits & Bobs...

Thanks for the links Paul.

I will put a few more hours into this before I go back to the Gertboard...

Bob Smith's picture

Re: Bits & Bobs...

Early morning success...

Using the Raspberry Pi/Gertboard I set the board to Arduino Uno in the IDE and burnt the bootloader to one of my ATMega's.

Swapped out the ATMega to the EmonTx and bingo, I can now upload sketches using the programmer.

Will let you know if doing it this way causes any other issues.

Thanks for the help...

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