Fighting with computers

Computers are not always friendly.

Tuesday, October 29, 2013

Teaching Rambo how to print

I could not resist the temptation and I bought a discounted RAMBo board a while ago. Today each
attempt to upload some code ended up in a list of messages like the ones below:

avrdude: stk500v2_ReceiveMessage(): timeout
avrdude: stk500v2_getsync(): timeout communicating with programmer

First idea was that the board might not contain a bootloader, but after using my recently acquired ICSP programmer and obtaining a dump of the ATMega 2560 from the board I could see it was exactly the same as the one from a regular Arduino Mega board. 

As it is a new board, there is a chance of being a DOA. But I was surprised that no LED was lit when I connected the USB port. However, I could see one of the LEDs from the serial port (I guessed this is what they were) blinking when I was trying (unsuccessfully) to upload a sketch to the board.

I realize that while I dumped the flash memory of the Mega, more LEDs were lit. It then hit me that maybe the only problem was that the board (the version I am using has no supply source selection) was not working because it was not being properly powered. So I connected a 12v power supply to the proper input and I was able to upload code to the board flawlessly. I should have tried this in the first place.

Monday, October 28, 2013

My printer port is gone!

After the last change of computer I was asked for help to installed the bootloader on an ATMega 1284P processor for controlling a 3D printer. I have been using for years the Arduino Parallel Port Programmer with great success (it worked every time if I remembered to power the board through USB at the same time).

But it turns out my new desktop computer does no longer has a parallel port. Not a big deal as all my printing happens through the network, but it was a no go for any type of other fancy uses of the parallel port (no, I do not have a CNC machine controlled with EMC2, though I have EMC2 software installed in my computer).

So I finally gave in and ordered a USBASP programmer that was less than 5€ off eBay and fixes the need for a tool for uploading bootloaders to new boards. It comes with a 10 to 6pin adapter too, which was needed for Arduino boards ISP connection.

You can use it from the command line with avrdude program or from Arduino environment selecting USBASP as the type of programmer. It is not very fast but it gets the work done. Highly recommended.